Science.gov

Sample records for air-ground traffic management

  1. ADS-B within a Multi-Aircraft Simulation for Distributed Air-Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Palmer, Michael T.; Chung, William W.; Loveness, Ghyrn W.

    2004-01-01

    Automatic Dependent Surveillance Broadcast (ADS-B) is an enabling technology for NASA s Distributed Air-Ground Traffic Management (DAG-TM) concept. DAG-TM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, aircraft exchange state and intent information over ADS-B with other aircraft and ground stations. This information supports various surveillance functions including conflict detection and resolution, scheduling, and conformance monitoring. To conduct more rigorous concept feasibility studies, NASA Langley Research Center s PC-based Air Traffic Operations Simulation models a 1090 MHz ADS-B communication structure, based on industry standards for message content, range, and reception probability. The current ADS-B model reflects a mature operating environment and message interference effects are limited to Mode S transponder replies and ADS-B squitters. This model was recently evaluated in a Joint DAG-TM Air/Ground Coordination Experiment with NASA Ames Research Center. Message probability of reception vs. range was lower at higher traffic levels. The highest message collision probability occurred near the meter fix serving as the confluence for two arrival streams. Even the highest traffic level encountered in the experiment was significantly less than the industry standard "LA Basin 2020" scenario. Future studies will account for Mode A and C message interference (a major effect in several industry studies) and will include Mode A and C aircraft in the simulation, thereby increasing the total traffic level. These changes will support ongoing enhancements to separation assurance functions that focus on accommodating longer ADS-B information update intervals.

  2. NASA Langley and NLR Research of Distributed Air/Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Ballin, Mark G.; Hoekstra, Jacco M.; Wing, David J.; Lohr, Gary W.

    2002-01-01

    Distributed Air/Ground Traffic Management (DAG-TM) is a concept of future air traffic operations that proposes to distribute information, decision-making authority, and responsibility among flight crews, the air traffic service provider, and aeronautical operational control organizations. This paper provides an overview and status of DAG-TM research at NASA Langley Research Center and the National Aerospace Laboratory of The Netherlands. Specific objectives of the research are to evaluate the technical and operational feasibility of the autonomous airborne component of DAG-TM, which is founded on the operational paradigm of free flight. The paper includes an overview of research approaches, the airborne technologies under development, and a summary of experimental investigations and findings to date. Although research is not yet complete, these findings indicate that free flight is feasible and will significantly enhance system capacity and safety. While free flight cannot alone resolve the complex issues faced by those modernizing the global airspace, it should be considered an essential part of a comprehensive air traffic management modernization activity.

  3. Advanced Air Transportation Technologies (AATT) Project: Distributed Air-Ground Traffic Management

    NASA Technical Reports Server (NTRS)

    Mogford, Richard; Green, Steve; Ballin, Mark

    2002-01-01

    This viewgraph presentation provides an overview of active Distributed Air Ground Traffic Management (DAG-TM) work and reported on its overall progress to date. It does not include details on the concept elements (CEs).The DAG-TM research project is defined as a concept development and definition project and no tools will be delivered. Of the 14 CEs, three are being explored actively: CE-5, CE-6, and CE-11. Overviews of CE-5 (Free Maneuvering for User-Preferred Separation Assurance and Local TFM Conformance), CE-6 (En Route and Transition Trajectory Negotiation for User-Preferred Separation and Local TFM Conformance) and CE-11 (Self-Spacing for Merging and In-Trail Separation) are presented.

  4. Profile negotiation: An air/ground automation integration concept for managing arrival traffic

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Arbuckle, P. Douglas; Green, Steven M.; Denbraven, Wim

    1993-01-01

    NASA Ames Research Center and NASA Langley Research Center conducted a joint simulation study to evaluate a profile negotiation process (PNP) between a time-based air traffic control ATC system and an airplane equipped with a four dimensional flight management system (4D FMS). Prototype procedures were developed to support the functional implementation of this process. The PNP was designed to provide an arrival trajectory solution that satisfies the separation requirements of ATC while remaining as close as possible to the airplane's preferred trajectory. The Transport Systems Research Vehicle cockpit simulator was linked in real-time to the Center/TRACON Automation System (CTAS) for the experiment. Approximately 30 hours of simulation testing were conducted over a three week period. Active airline pilot crews and active Center controller teams participated as test subjects. Results from the experiment indicate the potential for successful incorporation of airplane preferred arrival trajectories in the CTAS automation environment. Controllers were able to consistently and effectively negotiate nominally conflict-free trajectories with pilots flying a 4D-FMS-equipped airplane. The negotiated trajectories were substantially closer to the airplane's preference than would have otherwise been possible without the PNP. Airplane fuel savings relative to baseline CTAS were achieved in the test scenarios. The datalink procedures and clearances developed for this experiment, while providing the necessary functionality, were found to be operationally unacceptable to the pilots. Additional pilot control and understanding of the proposed airplane-preferred trajectory and a simplified clearance procedure were cited as necessary for operational implementation of the concept. From the controllers' perspective, the main concerns were the ability of the 4D airplane to accurately track the negotiated trajectory and the workload required to support the PNP as implemented in this study.

  5. Airborne Use of Traffic Intent Information in a Distributed Air-Ground Traffic Management Concept: Experiment Design and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Adams, Richard J.; Barmore, Bryan E.; Moses, Donald

    2002-01-01

    This paper presents initial findings of a research study designed to provide insight into the issue of intent information exchange in constrained en-route air-traffic operations and its effect on pilot decision making and flight performance. The piloted simulation was conducted in the Air Traffic Operations Laboratory at the NASA Langley Research Center. Two operational modes for autonomous operations were compared under conditions of low and high operational complexity. The tactical mode was characterized primarily by the use of state information for conflict detection and resolution and an open-loop means for the pilot to meet operational constraints. The strategic mode involved the combined use of state and intent information, provided the pilot an additional level of alerting, and allowed a closed-loop approach to meeting operational constraints. Operational constraints included separation assurance, schedule adherence, airspace hazard avoidance, flight efficiency, and passenger comfort. Potential operational benefits of both modes are illustrated through several scenario case studies. Subjective pilot ratings and comments comparing the tactical and strategic modes are presented.

  6. Airborne Use of Traffic Intent Information in a Distributed Air-Ground Traffic Management Concept: Experiment Design and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Adams, Richard J.; Barmore, Bryan E.; Moses, Donald

    2001-01-01

    This paper presents initial findings of a research study designed to provide insight into the issue of intent information exchange in constrained en-route air-traffic operations and its effect on pilot decision making and flight performance. The piloted simulation was conducted in the Air Traffic Operations Laboratory at the NASA Langley Research Center. Two operational modes for autonomous operations were compared under conditions of low and high operational complexity. The tactical mode was characterized primarily by the use of state information for conflict detection and resolution and an open-loop means for the pilot to meet operational constraints. The strategic mode involved the combined use of state and intent information, provided the pilot an additional level of alerting, and allowed a closed-loop approach to meeting operational constraints. Operational constraints included separation assurance, schedule adherence, airspace hazard avoidance, flight efficiency, and passenger comfort. Potential operational benefits of both modes are illustrated through several scenario case studies. Subjective pilot ratings and comments comparing the tactical and strategic modes are presented.

  7. Design and evaluation of an advanced air-ground data-link system for air traffic control

    NASA Technical Reports Server (NTRS)

    Denbraven, Wim

    1992-01-01

    The design and evaluation of the ground-based portion of an air-ground data-link system for air traffic control (ATC) are described. The system was developed to support the 4D Aircraft/ATC Integration Study, a joint simulation experiment conducted at NASA's Ames and Langley Research Centers. The experiment focused on airborne and ground-based procedures for handling aircraft equipped with a 4D-Flight Management System (FMS) and the system requirements needed to ensure conflict-free traffic flow. The Center/TRACON Automation System (CTAS) at Ames was used for the ATC part of the experiment, and the 4D-FMS-equipped aircraft was simulated by the Transport Systems Research Vehicle (TSRV) simulator at Langley. The data-link system supported not only conventional ATC communications, but also the communications needed to accommodate the 4D-FMS capabilities of advanced aircraft. Of great significance was the synergism gained from integrating the data link with CTAS. Information transmitted via the data link was used to improve the monitoring and analysis capability of CTAS without increasing controller input workload. Conversely, CTAS was used to anticipate and create prototype messages, thus reducing the workload associated with the manual creation of data-link messages.

  8. Piloted simulation of an air-ground profile negotiation process in a time-based Air Traffic Control environment

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Green, Steven M.

    1993-01-01

    Historically, development of airborne flight management systems (FMS) and ground-based air traffic control (ATC) systems has tended to focus on different objectives with little consideration for operational integration. A joint program, between NASA's Ames Research Center (Ames) and Langley Research Center (Langley), is underway to investigate the issues of, and develop systems for, the integration of ATC and airborne automation systems. A simulation study was conducted to evaluate a profile negotiation process (PNP) between the Center/TRACON Automation System (CTAS) and an aircraft equipped with a four-dimensional flight management system (4D FMS). Prototype procedures were developed to support the functional implementation of this process. The PNP was designed to provide an arrival trajectory solution which satisfies the separation requirements of ATC while remaining as close as possible to the aircraft's preferred trajectory. Results from the experiment indicate the potential for successful incorporation of aircraft-preferred arrival trajectories in the CTAS automation environment. Fuel savings on the order of 2 percent to 8 percent, compared to fuel required for the baseline CTAS arrival speed strategy, were achieved in the test scenarios. The data link procedures and clearances developed for this experiment, while providing the necessary functionality, were found to be operationally unacceptable to the pilots. In particular, additional pilot control and understanding of the proposed aircraft-preferred trajectory, and a simplified clearance procedure were cited as necessary for operational implementation of the concept.

  9. Surface Traffic Management Research

    NASA Technical Reports Server (NTRS)

    Jung, Yoo Chul

    2012-01-01

    This presentation discusses an overview of the surface traffic management research conducted by NASA Ames. The concept and human-in-the-loop simulation of the Spot and Runway Departure Advisor (SARDA), an integrated decision support tool for the tower controllers and airline ramp operators, is also discussed.

  10. Virginia's traffic management system

    SciTech Connect

    Morris, J.; Marber, S. )

    1992-07-01

    This paper reports that Northern Virginia, like most other urban areas, faces the challenge of moving more and more vehicles on roads that are already overloaded. Traffic in Northern Virginia is continually increasing, but the development surrounding Interstate 395, 495, and 66 makes little room available for roadway expansion. Even if land were unlimited, the strict requirement of the Clean Air Act make building roads difficult. This paper reports that ensuring the most efficient use of the interstate highways is the goal of the Virginia Department of Transportation's (VDOT's) traffic management system (TMS). TMS is a computerized highway surveillance and control system that monitors 30 interstate miles on I-395, I-495, and I-66. The system helps squeeze the most use from these interstates by detecting and helping clear accidents or disabled vehicles and by smoothing traffic flow. TMS spots and helps clear an average of two incidents a day and prevents accidents caused by erratic traffic flow from ramps onto the main line. For motorists, these TMS functions translate into decreased travel time, vehicle operating costs, and air pollution. VDOT's TMS is the foundation for the intelligent vehicle-highway systems of tomorrow. It employs several elements that work together to improve traffic flow.

  11. Traffic Flow Management and Optimization

    NASA Technical Reports Server (NTRS)

    Rios, Joseph Lucio

    2014-01-01

    This talk will present an overview of Traffic Flow Management (TFM) research at NASA Ames Research Center. Dr. Rios will focus on his work developing a large-scale, parallel approach to solving traffic flow management problems in the national airspace. In support of this talk, Dr. Rios will provide some background on operational aspects of TFM as well a discussion of some of the tools needed to perform such work including a high-fidelity airspace simulator. Current, on-going research related to TFM data services in the national airspace system and general aviation will also be presented.

  12. Airborne Use of Traffic Intent Information in a Distributed Air-Ground Traffic Management Concept: Experiment Design and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Adams, Richard J.; Duley, Jacqueline A.; Legan, Brian M.; Barmore, Bryan E.; Moses, Donald

    2001-01-01

    A predominant research focus in the free flight community has been on the type of information required on the flight deck to enable pilots to "autonomously" maintain separation from other aircraft. At issue are the relative utility and requirement for information exchange between aircraft regarding the current "state" and/or the "intent" of each aircraft. This paper presents the experimental design and some initial findings of an experimental research study designed to provide insight into the issue of intent information exchange in constrained en-route operations and its effect on pilot decision making and flight performance. Two operational modes for autonomous operations were compared in a piloted simulation. The tactical mode was characterized primarily by the use of state information for conflict detection and resolution and an open-loop means for the pilot to meet operational constraints. The strategic mode involved the combined use of state and intent information, provided the pilot an additional level of alerting, and allowed a closed-loop approach to meeting operational constraints. Potential operational benefits of both modes are illustrated through several scenario case studies. Subjective data results are presented that generally indicate pilot consensus in favor of the strategic mode.

  13. Air traffic management evaluation tool

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar (Inventor); Sheth, Kapil S. (Inventor); Chatterji, Gano Broto (Inventor); Bilimoria, Karl D. (Inventor); Grabbe, Shon (Inventor); Schipper, John F. (Inventor)

    2010-01-01

    Method and system for evaluating and implementing air traffic management tools and approaches for managing and avoiding an air traffic incident before the incident occurs. The invention provides flight plan routing and direct routing or wind optimal routing, using great circle navigation and spherical Earth geometry. The invention provides for aircraft dynamics effects, such as wind effects at each altitude, altitude changes, airspeed changes and aircraft turns to provide predictions of aircraft trajectory (and, optionally, aircraft fuel use). A second system provides several aviation applications using the first system. These applications include conflict detection and resolution, miles-in trail or minutes-in-trail aircraft separation, flight arrival management, flight re-routing, weather prediction and analysis and interpolation of weather variables based upon sparse measurements.

  14. Automatic speech recognition in air-ground data link

    NASA Technical Reports Server (NTRS)

    Armstrong, Herbert B.

    1989-01-01

    In the present air traffic system, information presented to the transport aircraft cockpit crew may originate from a variety of sources and may be presented to the crew in visual or aural form, either through cockpit instrument displays or, most often, through voice communication. Voice radio communications are the most error prone method for air-ground data link. Voice messages can be misstated or misunderstood and radio frequency congestion can delay or obscure important messages. To prevent proliferation, a multiplexed data link display can be designed to present information from multiple data link sources on a shared cockpit display unit (CDU) or multi-function display (MFD) or some future combination of flight management and data link information. An aural data link which incorporates an automatic speech recognition (ASR) system for crew response offers several advantages over visual displays. The possibility of applying ASR to the air-ground data link was investigated. The first step was to review current efforts in ASR applications in the cockpit and in air traffic control and evaluated their possible data line application. Next, a series of preliminary research questions is to be developed for possible future collaboration.

  15. Air traffic management evaluation tool

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar (Inventor); Sheth, Kapil S. (Inventor); Chatterji, Gano Broto (Inventor); Bilimoria, Karl D. (Inventor); Grabbe, Shon (Inventor); Schipper, John F. (Inventor)

    2012-01-01

    Methods for evaluating and implementing air traffic management tools and approaches for managing and avoiding an air traffic incident before the incident occurs. A first system receives parameters for flight plan configurations (e.g., initial fuel carried, flight route, flight route segments followed, flight altitude for a given flight route segment, aircraft velocity for each flight route segment, flight route ascent rate, flight route descent route, flight departure site, flight departure time, flight arrival time, flight destination site and/or alternate flight destination site), flight plan schedule, expected weather along each flight route segment, aircraft specifics, airspace (altitude) bounds for each flight route segment, navigational aids available. The invention provides flight plan routing and direct routing or wind optimal routing, using great circle navigation and spherical Earth geometry. The invention provides for aircraft dynamics effects, such as wind effects at each altitude, altitude changes, airspeed changes and aircraft turns to provide predictions of aircraft trajectory (and, optionally, aircraft fuel use). A second system provides several aviation applications using the first system. Several classes of potential incidents are analyzed and averted, by appropriate change en route of one or more parameters in the flight plan configuration, as provided by a conflict detection and resolution module and/or traffic flow management modules. These applications include conflict detection and resolution, miles-in trail or minutes-in-trail aircraft separation, flight arrival management, flight re-routing, weather prediction and analysis and interpolation of weather variables based upon sparse measurements. The invention combines these features to provide an aircraft monitoring system and an aircraft user system that interact and negotiate changes with each other.

  16. 41 CFR 109-40.301 - Traffic management functions administration.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Traffic management... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 40-TRANSPORTATION AND TRAFFIC MANAGEMENT 40.3-Traffic Management § 109-40.301 Traffic management functions administration. The DOE traffic management functions...

  17. 41 CFR 109-40.301 - Traffic management functions administration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Traffic management... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 40-TRANSPORTATION AND TRAFFIC MANAGEMENT 40.3-Traffic Management § 109-40.301 Traffic management functions administration. The DOE traffic management functions...

  18. 41 CFR 109-40.301 - Traffic management functions administration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Traffic management... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 40-TRANSPORTATION AND TRAFFIC MANAGEMENT 40.3-Traffic Management § 109-40.301 Traffic management functions administration. The DOE traffic management functions...

  19. 41 CFR 109-40.301 - Traffic management functions administration.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Traffic management... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 40-TRANSPORTATION AND TRAFFIC MANAGEMENT 40.3-Traffic Management § 109-40.301 Traffic management functions administration. The DOE traffic management functions...

  20. 41 CFR 109-40.301 - Traffic management functions administration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Traffic management... AVIATION, TRANSPORTATION, AND MOTOR VEHICLES 40-TRANSPORTATION AND TRAFFIC MANAGEMENT 40.3-Traffic Management § 109-40.301 Traffic management functions administration. The DOE traffic management functions...

  1. Dynamic Density: An Air Traffic Management Metric

    NASA Technical Reports Server (NTRS)

    Laudeman, I. V.; Shelden, S. G.; Branstrom, R.; Brasil, C. L.

    1998-01-01

    The definition of a metric of air traffic controller workload based on air traffic characteristics is essential to the development of both air traffic management automation and air traffic procedures. Dynamic density is a proposed concept for a metric that includes both traffic density (a count of aircraft in a volume of airspace) and traffic complexity (a measure of the complexity of the air traffic in a volume of airspace). It was hypothesized that a metric that includes terms that capture air traffic complexity will be a better measure of air traffic controller workload than current measures based only on traffic density. A weighted linear dynamic density function was developed and validated operationally. The proposed dynamic density function includes a traffic density term and eight traffic complexity terms. A unit-weighted dynamic density function was able to account for an average of 22% of the variance in observed controller activity not accounted for by traffic density alone. A comparative analysis of unit weights, subjective weights, and regression weights for the terms in the dynamic density equation was conducted. The best predictor of controller activity was the dynamic density equation with regression-weighted complexity terms.

  2. Air Traffic Management Research at NASA Ames

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.

    2012-01-01

    The Aviation Systems Division at the NASA Ames Research Center conducts leading edge research in air traffic management concepts and technologies. This overview will present concepts and simulation results for research in traffic flow management, safe and efficient airport surface operations, super density terminal area operations, separation assurance and system wide modeling and simulation. A brief review of the ongoing air traffic management technology demonstration (ATD-1) will also be presented. A panel discussion, with Mr. Davis serving as a panelist, on air traffic research will follow the briefing.

  3. Traffic Management for Satellite-ATM Networks

    NASA Technical Reports Server (NTRS)

    Goyal, Rohit; Jain, Raj; Fahmy, Sonia; Vandalore, Bobby; Goyal, Mukul

    1998-01-01

    Various issues associated with "Traffic Management for Satellite-ATM Networks" are presented in viewgraph form. Specific topics include: 1) Traffic management issues for TCP/IP based data services over satellite-ATM networks; 2) Design issues for TCP/IP over ATM; 3) Optimization of the performance of TCP/IP over ATM for long delay networks; and 4) Evaluation of ATM service categories for TCP/IP traffic.

  4. A Framework for Dimensioning VDL-2 Air-Ground Networks

    NASA Technical Reports Server (NTRS)

    Ribeiro, Leila Z.; Monticone, Leone C.; Snow, Richard E.; Box, Frank; Apaza, Rafel; Bretmersky, Steven

    2014-01-01

    This paper describes a framework developed at MITRE for dimensioning a Very High Frequency (VHF) Digital Link Mode 2 (VDL-2) Air-to-Ground network. This framework was developed to support the FAA's Data Communications (Data Comm) program by providing estimates of expected capacity required for the air-ground network services that will support Controller-Pilot-Data-Link Communications (CPDLC), as well as the spectrum needed to operate the system at required levels of performance. The Data Comm program is part of the FAA's NextGen initiative to implement advanced communication capabilities in the National Airspace System (NAS). The first component of the framework is the radio-frequency (RF) coverage design for the network ground stations. Then we proceed to describe the approach used to assess the aircraft geographical distribution and the data traffic demand expected in the network. The next step is the resource allocation utilizing optimization algorithms developed in MITRE's Spectrum ProspectorTM tool to propose frequency assignment solutions, and a NASA-developed VDL-2 tool to perform simulations and determine whether a proposed plan meets the desired performance requirements. The framework presented is capable of providing quantitative estimates of multiple variables related to the air-ground network, in order to satisfy established coverage, capacity and latency performance requirements. Outputs include: coverage provided at different altitudes; data capacity required in the network, aggregated or on a per ground station basis; spectrum (pool of frequencies) needed for the system to meet a target performance; optimized frequency plan for a given scenario; expected performance given spectrum available; and, estimates of throughput distributions for a given scenario. We conclude with a discussion aimed at providing insight into the tradeoffs and challenges identified with respect to radio resource management for VDL-2 air-ground networks.

  5. Traffic Flow Management Wrap-Up

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon

    2011-01-01

    Traffic Flow Management involves the scheduling and routing of air traffic subject to airport and airspace capacity constraints, and the efficient use of available airspace. Significant challenges in this area include: (1) weather integration and forecasting, (2) accounting for user preferences in the Traffic Flow Management decision making process, and (3) understanding and mitigating the environmental impacts of air traffic on the environment. To address these challenges, researchers in the Traffic Flow Management area are developing modeling, simulation and optimization techniques to route and schedule air traffic flights and flows while accommodating user preferences, accounting for system uncertainties and considering the environmental impacts of aviation. This presentation will highlight some of the major challenges facing researchers in this domain, while also showcasing recent innovations designed to address these challenges.

  6. Neural network system for traffic flow management

    NASA Astrophysics Data System (ADS)

    Gilmore, John F.; Elibiary, Khalid J.; Petersson, L. E. Rickard

    1992-09-01

    Atlanta will be the home of several special events during the next five years ranging from the 1996 Olympics to the 1994 Super Bowl. When combined with the existing special events (Braves, Falcons, and Hawks games, concerts, festivals, etc.), the need to effectively manage traffic flow from surface streets to interstate highways is apparent. This paper describes a system for traffic event response and management for intelligent navigation utilizing signals (TERMINUS) developed at Georgia Tech for adaptively managing special event traffic flows in the Atlanta, Georgia area. TERMINUS (the original name given Atlanta, Georgia based upon its role as a rail line terminating center) is an intelligent surface street signal control system designed to manage traffic flow in Metro Atlanta. The system consists of three components. The first is a traffic simulation of the downtown Atlanta area around Fulton County Stadium that models the flow of traffic when a stadium event lets out. Parameters for the surrounding area include modeling for events during various times of day (such as rush hour). The second component is a computer graphics interface with the simulation that shows the traffic flows achieved based upon intelligent control system execution. The final component is the intelligent control system that manages surface street light signals based upon feedback from control sensors that dynamically adapt the intelligent controller's decision making process. The intelligent controller is a neural network model that allows TERMINUS to control the configuration of surface street signals to optimize the flow of traffic away from special events.

  7. Air Traffic Management Technology Demostration: 1 Research and Procedural Testing of Routes

    NASA Technical Reports Server (NTRS)

    Wilson, Sara R.; Kibler, Jennifer L.; Hubbs, Clay E.; Smail, James W.

    2015-01-01

    NASA's Air Traffic Management Technology Demonstration-1 (ATD-1) will operationally demonstrate the feasibility of efficient arrival operations combining ground-based and airborne NASA technologies. The ATD-1 integrated system consists of the Traffic Management Advisor with Terminal Metering which generates precise time-based schedules to the runway and merge points; Controller Managed Spacing decision support tools which provide controllers with speed advisories and other information needed to meet the schedule; and Flight deck-based Interval Management avionics and procedures which allow flight crews to adjust their speed to achieve precise relative spacing. Initial studies identified air-ground challenges related to the integration of these three scheduling and spacing technologies, and NASA's airborne spacing algorithm was modified to address some of these challenges. The Research and Procedural Testing of Routes human-in-the-loop experiment was then conducted to assess the performance of the new spacing algorithm. The results of this experiment indicate that the algorithm performed as designed, and the pilot participants found the airborne spacing concept, air-ground procedures, and crew interface to be acceptable. However, the researchers concluded that the data revealed issues with the frequency of speed changes and speed reversals.

  8. Remotely Accessed Vehicle Traffic Management System

    NASA Astrophysics Data System (ADS)

    Al-Alawi, Raida

    2010-06-01

    The ever increasing number of vehicles in most metropolitan cities around the world and the limitation in altering the transportation infrastructure, led to serious traffic congestion and an increase in the travelling time. In this work we exploit the emergence of novel technologies such as the internet, to design an intelligent Traffic Management System (TMS) that can remotely monitor and control a network of traffic light controllers located at different sites. The system is based on utilizing Embedded Web Servers (EWS) technology to design a web-based TMS. The EWS located at each intersection uses IP technology for communicating remotely with a Central Traffic Management Unit (CTMU) located at the traffic department authority. Friendly GUI software installed at the CTMU will be able to monitor the sequence of operation of the traffic lights and the presence of traffic at each intersection as well as remotely controlling the operation of the signals. The system has been validated by constructing a prototype that resembles the real application.

  9. Joint NASA Ames/Langley Experimental Evaluation of Integrated Air/Ground Operations for En Route Free Maneuvering

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Kopardekar, Parimal; Battiste, Vernol; Doble, Nathan; Johnson, Walter; Lee, Paul; Prevot, Thomas; Smith, Nancy

    2005-01-01

    In order to meet the anticipated future demand for air travel, the National Aeronautics and Space Administration (NASA) is investigating a new concept of operations known as Distributed Air-Ground Traffic Management (DAG-TM). Under the En Route Free Maneuvering component of DAG-TM, appropriately equipped autonomous aircraft self separate from other autonomous aircraft and from managed aircraft that continue to fly under today s Instrument Flight Rules (IFR). Controllers provide separation services between IFR aircraft and assign traffic flow management constraints to all aircraft. To address concept feasibility issues pertaining to integrated air/ground operations at various traffic levels, NASA Ames and Langley Research Centers conducted a joint human-in-the-loop experiment. Professional airline pilots and air traffic controllers flew a total of 16 scenarios under four conditions: mixed autonomous/managed operations at three traffic levels and a baseline all-managed condition at the lowest traffic level. These scenarios included en route flights and descents to a terminal area meter fix in airspace modeled after the Dallas Ft. Worth area. Pilots of autonomous aircraft met controller assigned meter fix constraints with high success. Separation violations by subject pilots did not appear to vary with traffic level and were mainly attributable to software errors and procedural lapses. Controller workload was lower for mixed flight conditions, even at higher traffic levels. Pilot workload was deemed acceptable under all conditions. Controllers raised several safety concerns, most of which pertained to the occurrence of near-term conflicts between autonomous and managed aircraft. These issues are being addressed through better compatibility between air and ground systems and refinements to air and ground procedures.

  10. Personal Property Traffic Management Regulation

    DTIC Science & Technology

    1991-10-01

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  11. Automated Traffic Management System and Method

    NASA Technical Reports Server (NTRS)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2000-01-01

    A data management system and method that enables acquisition, integration, and management of real-time data generated at different rates, by multiple heterogeneous incompatible data sources. The system achieves this functionality by using an expert system to fuse data from a variety of airline, airport operations, ramp control, and air traffic control tower sources, to establish and update reference data values for every aircraft surface operation. The system may be configured as a real-time airport surface traffic management system (TMS) that electronically interconnects air traffic control, airline data, and airport operations data to facilitate information sharing and improve taxi queuing. In the TMS operational mode, empirical data shows substantial benefits in ramp operations for airlines, reducing departure taxi times by about one minute per aircraft in operational use, translating as $12 to $15 million per year savings to airlines at the Atlanta, Georgia airport. The data management system and method may also be used for scheduling the movement of multiple vehicles in other applications, such as marine vessels in harbors and ports, trucks or railroad cars in ports or shipping yards, and railroad cars in switching yards. Finally, the data management system and method may be used for managing containers at a shipping dock, stock on a factory floor or in a warehouse, or as a training tool for improving situational awareness of FAA tower controllers, ramp and airport operators, or commercial airline personnel in airfield surface operations.

  12. The Future of Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Denery, Dallas G.; Erzberger, Heinz; Edwards, Thomas A. (Technical Monitor)

    1998-01-01

    A system for the control of terminal area traffic to improve productivity, referred to as the Center-TRACON Automation System (CTAS), is being developed at NASA's Ames Research Center under a joint program with the FAA. CTAS consists of a set of integrated tools that provide computer-generated advisories for en-route and terminal area controllers. The premise behind the design of CTAS has been that successful planning of traffic requires accurate trajectory prediction. Data bases consisting of representative aircraft performance models, airline preferred operational procedures and a three dimensional wind model support the trajectory prediction. The research effort has been the design of a set of automation tools that make use of this trajectory prediction capability to assist controllers in overall management of traffic. The first tool, the Traffic Management Advisor (TMA), provides the overall flow management between the en route and terminal areas. A second tool, the Final Approach Spacing Tool (FAST) provides terminal area controllers with sequence and runway advisories to allow optimal use of the runways. The TMA and FAST are now being used in daily operations at Dallas/Ft. Worth airport. Additional activities include the development of several other tools. These include: 1) the En Route Descent Advisor that assist the en route controller in issuing conflict free descents and ascents; 2) the extension of FAST to include speed and heading advisories and the Expedite Departure Path (EDP) that assists the terminal controller in management of departures; and 3) the Collaborative Arrival Planner (CAP) that will assist the airlines in operational decision making. The purpose of this presentation is to review the CTAS concept and to present the results of recent field tests. The paper will first discuss the overall concept and then discuss the status of the individual tools.

  13. Technical Seminar: "Modeling and Optimization in Air Traffic Management"

    NASA Video Gallery

    Traffic Flow Management (TFM) is the efficient organization of traffic flows to meet demand taking into account capacity constraints at airports and in en route airspace. TFM involves thousands of ...

  14. Integrated Traffic Flow Management Decision Making

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon R.; Sridhar, Banavar; Mukherjee, Avijit

    2009-01-01

    A generalized approach is proposed to support integrated traffic flow management decision making studies at both the U.S. national and regional levels. It can consider tradeoffs between alternative optimization and heuristic based models, strategic versus tactical flight controls, and system versus fleet preferences. Preliminary testing was accomplished by implementing thirteen unique traffic flow management models, which included all of the key components of the system and conducting 85, six-hour fast-time simulation experiments. These experiments considered variations in the strategic planning look-ahead times, the replanning intervals, and the types of traffic flow management control strategies. Initial testing indicates that longer strategic planning look-ahead times and re-planning intervals result in steadily decreasing levels of sector congestion for a fixed delay level. This applies when accurate estimates of the air traffic demand, airport capacities and airspace capacities are available. In general, the distribution of the delays amongst the users was found to be most equitable when scheduling flights using a heuristic scheduling algorithm, such as ration-by-distance. On the other hand, equity was the worst when using scheduling algorithms that took into account the number of seats aboard each flight. Though the scheduling algorithms were effective at alleviating sector congestion, the tactical rerouting algorithm was the primary control for avoiding en route weather hazards. Finally, the modeled levels of sector congestion, the number of weather incursions, and the total system delays, were found to be in fair agreement with the values that were operationally observed on both good and bad weather days.

  15. Scheduling logic for Miles-In-Trail traffic management

    NASA Technical Reports Server (NTRS)

    Synnestvedt, Robert G.; Swenson, Harry; Erzberger, Heinz

    1995-01-01

    This paper presents an algorithm which can be used for scheduling arrival air traffic in an Air Route Traffic Control Center (ARTCC or Center) entering a Terminal Radar Approach Control (TRACON) Facility . The algorithm aids a Traffic Management Coordinator (TMC) in deciding how to restrict traffic while the traffic expected to arrive in the TRACON exceeds the TRACON capacity. The restrictions employed fall under the category of Miles-in-Trail, one of two principal traffic separation techniques used in scheduling arrival traffic . The algorithm calculates aircraft separations for each stream of aircraft destined to the TRACON. The calculations depend upon TRACON characteristics, TMC preferences, and other parameters adapted to the specific needs of scheduling traffic in a Center. Some preliminary results of traffic simulations scheduled by this algorithm are presented, and conclusions are drawn as to the effectiveness of using this algorithm in different traffic scenarios.

  16. Managed traffic evacuation using distributed sensor processing

    NASA Astrophysics Data System (ADS)

    Ramuhalli, Pradeep; Biswas, Subir

    2005-05-01

    This paper presents an integrated sensor network and distributed event processing architecture for managed in-building traffic evacuation during natural and human-caused disasters, including earthquakes, fire and biological/chemical terrorist attacks. The proposed wireless sensor network protocols and distributed event processing mechanisms offer a new distributed paradigm for improving reliability in building evacuation and disaster management. The networking component of the system is constructed using distributed wireless sensors for measuring environmental parameters such as temperature, humidity, and detecting unusual events such as smoke, structural failures, vibration, biological/chemical or nuclear agents. Distributed event processing algorithms will be executed by these sensor nodes to detect the propagation pattern of the disaster and to measure the concentration and activity of human traffic in different parts of the building. Based on this information, dynamic evacuation decisions are taken for maximizing the evacuation speed and minimizing unwanted incidents such as human exposure to harmful agents and stampedes near exits. A set of audio-visual indicators and actuators are used for aiding the automated evacuation process. In this paper we develop integrated protocols, algorithms and their simulation models for the proposed sensor networking and the distributed event processing framework. Also, efficient harnessing of the individually low, but collectively massive, processing abilities of the sensor nodes is a powerful concept behind our proposed distributed event processing algorithms. Results obtained through simulation in this paper are used for a detailed characterization of the proposed evacuation management system and its associated algorithmic components.

  17. Decentralized and Tactical Air Traffic Flow Management

    NASA Technical Reports Server (NTRS)

    Odoni, Amedeo R.; Bertsimas, Dimitris

    1997-01-01

    This project dealt with the following topics: 1. Review and description of the existing air traffic flow management system (ATFM) and identification of aspects with potential for improvement. 2. Identification and review of existing models and simulations dealing with all system segments (enroute, terminal area, ground) 3. Formulation of concepts for overall decentralization of the ATFM system, ranging from moderate decentralization to full decentralization 4. Specification of the modifications to the ATFM system required to accommodate each of the alternative concepts. 5. Identification of issues that need to be addressed with regard to: determination of the way the ATFM system would be operating; types of flow management strategies that would be used; and estimation of the effectiveness of ATFM with regard to reducing delay and re-routing costs. 6. Concept evaluation through identification of criteria and methodologies for accommodating the interests of stakeholders and of approaches to optimization of operational procedures for all segments of the ATFM system.

  18. Comprehensive Software Eases Air Traffic Management

    NASA Technical Reports Server (NTRS)

    2007-01-01

    To help air traffic control centers improve the safety and the efficiency of the National Airspace System, Ames Research Center developed the Future Air Traffic Management Concepts Evaluation Tool (FACET) software, which won NASA's 2006 "Software of the Year" competition. In 2005, Ames licensed FACET to Flight Explorer Inc., for integration into its Flight Explorer (version 6.0) software. The primary FACET features incorporated in the Flight Explorer software system alert airspace users to forecasted demand and capacity imbalances. Advance access to this information helps dispatchers anticipate congested sectors (airspace) and delays at airports, and decide if they need to reroute flights. FACET is now a fully integrated feature in the Flight Explorer Professional Edition (version 7.0). Flight Explorer Professional offers end-users other benefits, including ease of operation; automatic alerts to inform users of important events such as weather conditions and potential airport delays; and international, real-time flight coverage over Canada, the United Kingdom, New Zealand, and sections of the Atlantic and Pacific Oceans. Flight Explorer Inc. recently broadened coverage by partnering with Honeywell International Inc.'s Global Data Center, Blue Sky Network, Sky Connect LLC, SITA, ARINC Incorporated, Latitude Technologies Corporation, and Wingspeed Corporation, to track their aircraft anywhere in the world.

  19. Transportation and General Traffic Management, Change 2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This Handbook sets forth those transportation and general traffic management responsibilities, guidelines, and procedures governing the use of commercial and Government transportation for NASA. Transportation is an integral function of the logistic process, involving all activities incident to the movement of persons and things. The fundamental and continuous objectives of transportation are to control and diminish the time-distance of lines of communication by the most suitable means. The function of transportation is accomplished through, and encompasses all, the planning, direction, supervision, and execution of the technical, operational, and administrative tasks required to procure or furnish efficient and economical conveyance of cargo and personnel by all modes of commercial and Government transportation. This Handbook is applicable to NASA Headquarters and Field Installations.

  20. Pilot and Controller Workload and Situation Awareness with Three Traffic Management Concept

    NASA Technical Reports Server (NTRS)

    Vu, Kim-Phuong L.; Strybel, Thomas Z.; Kraut, Joshua; Bacon, Paige; Minakata, Katsumi; Battiste, Vernol; Johnson, Walter

    2010-01-01

    This paper reports on workload and situation awareness of pilots and controllers participating in a human-in-the-loop simulation using three different distributed air-ground traffic management concepts. Eight experimental pilots started the scenario in an en-route phase of flight and were asked to avoid convective weather while performing spacing and merging tasks along with a continuous descent approach (CDA) into Louisville Standiford Airport (SDF). Two controllers managed the sectors through which the pilots flew, with one managing a sector that included the Top of Descent, and the other managing a sector that included the merge point for arrival into SDF. At 3-minute intervals in the scenario, pilots and controllers were probed on their workload or situation awareness. We employed one of three concepts of operation that distributed separation responsibility across human controllers, pilots, and automation to measure changes in operator situation awareness and workload. We found that when pilots were responsible for separation, they had higher levels of awareness, but not necessarily higher levels of workload. When controllers are responsible and actively engaged, they showed higher workload levels compared to pilots and changes in awareness that were dependent on sector characteristics.

  1. Delay Banking for Managing Air Traffic

    NASA Technical Reports Server (NTRS)

    Green, Steve

    2008-01-01

    Delay banking has been invented to enhance air-traffic management in a way that would increase the degree of fairness in assigning arrival, departure, and en-route delays and trajectory deviations to aircraft impacted by congestion in the national airspace system. In delay banking, an aircraft operator (airline, military, general aviation, etc.) would be assigned a numerical credit when any of their flights are delayed because of an air-traffic flow restriction. The operator could subsequently bid against other operators competing for access to congested airspace to utilize part or all of its accumulated credit. Operators utilize credits to obtain higher priority for the same flight, or other flights operating at the same time, or later, in the same airspace, or elsewhere. Operators could also trade delay credits, according to market rules that would be determined by stakeholders in the national airspace system. Delay banking would be administered by an independent third party who would use delay banking automation to continually monitor flights, allocate delay credits, maintain accounts of delay credits for participating airlines, mediate bidding and the consumption of credits of winning bidders, analyze potential transfers of credits within and between operators, implement accepted transfers, and ensure fair treatment of all participating operators. A flow restriction can manifest itself in the form of a delay in assigned takeoff time, a reduction in assigned airspeed, a change in the position for the aircraft in a queue of all aircraft in a common stream of traffic (e.g., similar route), a change in the planned altitude profile for an aircraft, or change in the planned route for the aircraft. Flow restrictions are typically imposed to mitigate traffic congestion at an airport or in a region of airspace, particularly congestion due to inclement weather, or the unavailability of a runway or region of airspace. A delay credit would be allocated to an operator of a

  2. Active traffic management on road networks: a macroscopic approach.

    PubMed

    Kurzhanskiy, Alex A; Varaiya, Pravin

    2010-10-13

    Active traffic management (ATM) is the ability to dynamically manage recurrent and non-recurrent congestion based on prevailing traffic conditions in order to maximize the effectiveness and efficiency of road networks. It is a continuous process of (i) obtaining and analysing traffic measurement data, (ii) operations planning, i.e. simulating various scenarios and control strategies, (iii) implementing the most promising control strategies in the field, and (iv) maintaining a real-time decision support system that filters current traffic measurements to predict the traffic state in the near future, and to suggest the best available control strategy for the predicted situation. ATM relies on a fast and trusted traffic simulator for the rapid quantitative assessment of a large number of control strategies for the road network under various scenarios, in a matter of minutes. The open-source macrosimulation tool Aurora ROAD NETWORK MODELER is a good candidate for this purpose. The paper describes the underlying dynamical traffic model and what it takes to prepare the model for simulation; covers the traffic performance measures and evaluation of scenarios as part of operations planning; introduces the framework within which the control strategies are modelled and evaluated; and presents the algorithm for real-time traffic state estimation and short-term prediction.

  3. ATD-2 IADS Metroplex Traffic Management Overview Brief

    NASA Technical Reports Server (NTRS)

    Engelland, Shawn

    2016-01-01

    ATD-2 will improve the predictability and the operational efficiency of the air traffic system in metroplex environments through the enhancement, development and integration of the nation's most advanced and sophisticated arrival, departure, and surface prediction, scheduling and management systems.

  4. Airborne Management of Traffic Conflicts in Descent With Arrival Constraints

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Barhydt, Richard; Krishnamurthy, Karthik

    2005-01-01

    NASA is studying far-term air traffic management concepts that may increase operational efficiency through a redistribution of decisionmaking authority among airborne and ground-based elements of the air transportation system. One component of this research, En Route Free Maneuvering, allows trained pilots of equipped autonomous aircraft to assume responsibility for traffic separation. Ground-based air traffic controllers would continue to separate traffic unequipped for autonomous operations and would issue flow management constraints to all aircraft. To evaluate En Route Free Maneuvering operations, a human-in-the-loop experiment was jointly conducted by the NASA Ames and Langley Research Centers. In this experiment, test subject pilots used desktop flight simulators to resolve conflicts in cruise and descent, and to adhere to air traffic flow constraints issued by test subject controllers. Simulators at NASA Langley were equipped with a prototype Autonomous Operations Planner (AOP) flight deck toolset to assist pilots with conflict management and constraint compliance tasks. Results from the experiment are presented, focusing specifically on operations during the initial descent into the terminal area. Airborne conflict resolution performance in descent, conformance to traffic flow management constraints, and the effects of conflicting traffic on constraint conformance are all presented. Subjective data from subject pilots are also presented, showing perceived levels of workload, safety, and acceptability of autonomous arrival operations. Finally, potential AOP functionality enhancements are discussed along with suggestions to improve arrival procedures.

  5. Design of automated system for management of arrival traffic

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Nedell, William

    1989-01-01

    The design of an automated air traffic control system based on a hierarchy of advisory tools for controllers is described. Compatibility of the tools with the human controller, a key objective of the design, is achieved by a judicious selection of tasks to be automated and careful attention to the design of the controller system interface. The design comprises three interconnected subsystems referred to as the Traffic Management Advisor, the Descent Advisor, and the Final Approach Spacing Tool. Each of these subsystems provides a collection of tools for specific controller positions and tasks. The design of two of these tools, the Descent Advisor, which provides automation tools for managing descent traffic, and the Traffic Management Advisor, which generates optimum landing schedules is focused on. The algorithms, automation modes, and graphical interfaces incorporated in the design are described.

  6. Directing Traffic: Managing Internet Bandwidth Fairly

    ERIC Educational Resources Information Center

    Paine, Thomas A.; Griggs, Tyler J.

    2008-01-01

    Educational institutions today face budgetary restraints and scarce resources, complicating the decision of how to allot bandwidth for campus network users. Additionally, campus concerns over peer-to-peer networking (specifically outbound Internet traffic) have increased because of bandwidth and copyright issues. In this article, the authors…

  7. Evolutionary Concepts for Decentralized Air Traffic Flow Management

    NASA Technical Reports Server (NTRS)

    Adams, Milton; Kolitz, Stephan; Milner, Joseph; Odoni, Amedeo

    1997-01-01

    Alternative concepts for modifying the policies and procedures under which the air traffic flow management system operates are described, and an approach to the evaluation of those concepts is discussed. Here, air traffic flow management includes all activities related to the management of the flow of aircraft and related system resources from 'block to block.' The alternative concepts represent stages in the evolution from the current system, in which air traffic management decision making is largely centralized within the FAA, to a more decentralized approach wherein the airlines and other airspace users collaborate in air traffic management decision making with the FAA. The emphasis in the discussion is on a viable medium-term partially decentralized scenario representing a phase of this evolution that is consistent with the decision-making approaches embodied in proposed Free Flight concepts for air traffic management. System-level metrics for analyzing and evaluating the various alternatives are defined, and a simulation testbed developed to generate values for those metrics is described. The fundamental issue of modeling airline behavior in decentralized environments is also raised, and an example of such a model, which deals with the preservation of flight bank integrity in hub airports, is presented.

  8. Air Traffic Management Research at NASA Ames Research Center

    NASA Technical Reports Server (NTRS)

    Lee, Katharine

    2005-01-01

    Since the late 1980's, NASA Ames researchers have been investigating ways to improve the air transportation system through the development of decision support automation. These software advances, such as the Center-TRACON Automation System (eTAS) have been developed with teams of engineers, software developers, human factors experts, and air traffic controllers; some ASA Ames decision support tools are currently operational in Federal Aviation Administration (FAA) facilities and some are in use by the airlines. These tools have provided air traffic controllers and traffic managers the capabilities to help reduce overall delays and holding, and provide significant cost savings to the airlines as well as more manageable workload levels for air traffic service providers. NASA is continuing to collaborate with the FAA, as well as other government agencies, to plan and develop the next generation of decision support tools that will support anticipated changes in the air transportation system, including a projected increase to three times today's air-traffic levels by 2025. The presentation will review some of NASA Ames' recent achievements in air traffic management research, and discuss future tool developments and concepts currently under consideration.

  9. Distributed and Centralized Conflict Management Under Traffic Flow Management Constraints

    NASA Technical Reports Server (NTRS)

    Feron, Eric; Bilimoria, Karl (Technical Monitor)

    2003-01-01

    Current air transportation in the United States relies on a system born half a century ago. While demand for air travel has kept increasing over the years, technologies at the heart of the National Airspace System (NAS) have not been able to follow an adequate evolution. For instance, computers used to centralize flight data in airspace sectors run a software developed in 1972. Safety, as well as certification and portability issues arise as major obstacles for the improvement of the system. The NAS is a structure that has never been designed, but has rather evolved over time. This has many drawbacks, mainly due to a lack of integration and engineering leading to many inefficiencies and losses of performance. To improve the operations, understanding of this complex needs to be built up to a certain level. This work presents research done on Air Traffic Management (ATM) at the level of the en-route sector.

  10. Whiteboards and discharge traffic lights: visual management in acute care.

    PubMed

    O'Brien, Lauri; Bassham, Jane; Lewis, Melissa

    2015-04-01

    Flinders Medical Centre was experiencing issues with timely discharge and knowing the potential discharges and in-patient bed capacity for the next day. This case study describes the application of 'visual management' theory to discharge processes. The solutions developed were 'patient journey boards' and 'discharge traffic lights'. The implementation of these visual management systems has enabled the hospital to improve its discharge processes.

  11. Air Traffic Management Research at NASA

    NASA Technical Reports Server (NTRS)

    Farley, Todd

    2012-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control systems aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Part of NASA's current mission in aeronautics research is to invent new technologies and procedures for ATC that will enable our national airspace system to accommodate the increasing demand for air transportation well into the next generation while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we'll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and we'll highlight some new NASA technologies coming down the pike.

  12. Distributed Traffic Complexity Management by Preserving Trajectory Flexibility

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Vivona, Robert A.; Garcia-Chico, Jose-Luis; Wing, David J.

    2007-01-01

    In order to handle the expected increase in air traffic volume, the next generation air transportation system is moving towards a distributed control architecture, in which groundbased service providers such as controllers and traffic managers and air-based users such as pilots share responsibility for aircraft trajectory generation and management. This paper presents preliminary research investigating a distributed trajectory-oriented approach to manage traffic complexity, based on preserving trajectory flexibility. The underlying hypotheses are that preserving trajectory flexibility autonomously by aircraft naturally achieves the aggregate objective of avoiding excessive traffic complexity, and that trajectory flexibility is increased by collaboratively minimizing trajectory constraints without jeopardizing the intended air traffic management objectives. This paper presents an analytical framework in which flexibility is defined in terms of robustness and adaptability to disturbances and preliminary metrics are proposed that can be used to preserve trajectory flexibility. The hypothesized impacts are illustrated through analyzing a trajectory solution space in a simple scenario with only speed as a degree of freedom, and in constraint situations involving meeting multiple times of arrival and resolving conflicts.

  13. Multi-Center Traffic Management Advisor Operational Field Test Results

    NASA Technical Reports Server (NTRS)

    Farley, Todd; Landry, Steven J.; Hoang, Ty; Nickelson, Monicarol; Levin, Kerry M.; Rowe, Dennis W.

    2005-01-01

    The Multi-Center Traffic Management Advisor (McTMA) is a research prototype system which seeks to bring time-based metering into the mainstream of air traffic control (ATC) operations. Time-based metering is an efficient alternative to traditional air traffic management techniques such as distance-based spacing (miles-in-trail spacing) and managed arrival reservoirs (airborne holding). While time-based metering has demonstrated significant benefit in terms of arrival throughput and arrival delay, its use to date has been limited to arrival operations at just nine airports nationally. Wide-scale adoption of time-based metering has been hampered, in part, by the limited scalability of metering automation. In order to realize the full spectrum of efficiency benefits possible with time-based metering, a much more modular, scalable time-based metering capability is required. With its distributed metering architecture, multi-center TMA offers such a capability.

  14. A shared data environment for the Military Traffic Management Command Directorate of International Traffic

    SciTech Connect

    Russell, D.L.; Wheeler, V.V. ); Truett, L.F. )

    1992-01-01

    In September 1991, Oak Ridge National Laboratory (ORNL) completed tasking to assist the Military Traffic Management Command Directorate of International Traffic (MTIT) in the analysis of a potential Shared Data Environment (SDE) for MTIT automated cargo traffic systems. This analysis was a preliminary effort with emphasis on documentation of requirements, examination of design alternatives, and identification of specific MTIT systems' data sharing problems. This report records the results of the ORNL analysis. The SDE envisioned by ORNL at this point in the analysis is not merely a repository of information; it is also a system that allows processing of distributed data. To provide high-level access to and control over international cargo processes, ORNL recommends a loosely coupled, replicated database design with high-speed communications among all sites.

  15. A shared data environment for the Military Traffic Management Command Directorate of International Traffic

    SciTech Connect

    Russell, D.L.; Wheeler, V.V.; Truett, L.F.

    1992-01-01

    In September 1991, Oak Ridge National Laboratory (ORNL) completed tasking to assist the Military Traffic Management Command Directorate of International Traffic (MTIT) in the analysis of a potential Shared Data Environment (SDE) for MTIT automated cargo traffic systems. This analysis was a preliminary effort with emphasis on documentation of requirements, examination of design alternatives, and identification of specific MTIT systems` data sharing problems. This report records the results of the ORNL analysis. The SDE envisioned by ORNL at this point in the analysis is not merely a repository of information; it is also a system that allows processing of distributed data. To provide high-level access to and control over international cargo processes, ORNL recommends a loosely coupled, replicated database design with high-speed communications among all sites.

  16. Interaction of Airspace Partitions and Traffic Flow Management Delay

    NASA Technical Reports Server (NTRS)

    Palopo, Kee; Chatterji, Gano B.; Lee, Hak-Tae

    2010-01-01

    To ensure that air traffic demand does not exceed airport and airspace capacities, traffic management restrictions, such as delaying aircraft on the ground, assigning them different routes and metering them in the airspace, are implemented. To reduce the delays resulting from these restrictions, revising the partitioning of airspace has been proposed to distribute capacity to yield a more efficient airspace configuration. The capacity of an airspace partition, commonly referred to as a sector, is limited by the number of flights that an air traffic controller can safely manage within the sector. Where viable, re-partitioning of the airspace distributes the flights over more efficient sectors and reduces individual sector demand. This increases the overall airspace efficiency, but requires additional resources in some sectors in terms of controllers and equipment, which is undesirable. This study examines the tradeoff of the number of sectors designed for a specified amount of traffic in a clear-weather day and the delays needed for accommodating the traffic demand. Results show that most of the delays are caused by airport arrival and departure capacity constraints. Some delays caused by airspace capacity constraints can be eliminated by re-partitioning the airspace. Analyses show that about 360 high-altitude sectors, which are approximately today s operational number of sectors of 373, are adequate for delays to be driven solely by airport capacity constraints for the current daily air traffic demand. For a marginal increase of 15 seconds of average delay, the number of sectors can be reduced to 283. In addition, simulations of traffic growths of 15% and 20% with forecasted airport capacities in the years 2018 and 2025 show that delays will continue to be governed by airport capacities. In clear-weather days, for small increases in traffic demand, increasing sector capacities will have almost no effect on delays.

  17. A Perspective on NASA Ames Air Traffic Management Research

    NASA Technical Reports Server (NTRS)

    Schroeder, Jeffery A.

    2012-01-01

    This paper describes past and present air-traffic-management research at NASA Ames Research Center. The descriptions emerge from the perspective of a technical manager who supervised the majority of this research for the last four years. Past research contributions built a foundation for calculating accurate flight trajectories to enable efficient airspace management in time. That foundation led to two predominant research activities that continue to this day - one in automatically separating aircraft and the other in optimizing traffic flows. Today s national airspace uses many of the applications resulting from research at Ames. These applications include the nationwide deployment of the Traffic Management Advisor, new procedures enabling continuous descent arrivals, cooperation with industry to permit more direct flights to downstream way-points, a surface management system in use by two cargo carriers, and software to evaluate how well flights conform to national traffic management initiatives. The paper concludes with suggestions for prioritized research in the upcoming years. These priorities include: enabling more first-look operational evaluations, improving conflict detection and resolution for climbing or descending aircraft, and focusing additional attention on the underpinning safety critical items such as a reliable datalink.

  18. Metro manila transport and traffic management plan (1993-1998)

    SciTech Connect

    Cal, P.C.

    1995-12-31

    In 1988, former President Corazon Aquino created the Presidential Task Force on Traffic Management to formulate plans and programs to improve the traffic situation in Metro Manila and to address the emerging problem of air pollution and concern on renewable energy sources for transportation. The Task Force formulated the Metro Manila Traffic Improvement Plan (TRIP) which was approved by President Aquino for implementation. TRIP called for the development of a mass urban transport system, which included the expansion of the light rail transit system and the construction and improvement of the Metro Manila road network. Culled mainly from the TRIP proposals, the Updated Transport and Traffic Management Plan for Metro Manila (1993-1998) was developed through interagency discussions, public consultations, data collation and research work. This plan is directed towards the development of a more responsive public transport system, expansion of road network capacity, and improvement of traffic management and enforcement. Constraints may be present along the way but opportunities and potentials exist for the deliverance of daily commuters struggling to make a living.

  19. Traffic Incident Management in the Presence of Hazards

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Zlatanova, S.; Steenbruggen, J.

    2016-09-01

    Traffic incidents can result in different kinds of hazards (e.g., plumes) that influence the status of road networks, therefore there is a great need for incident management in the presence of the hazards. When incidents occur, the created hazards not only affect the normal road users (make them detour or blocked), but also influence the movement of first responders. Traffic managers, who are responsible for maintaining the road safety and traffic stability, should carry out quick and effective measures to manage the incidents. In this paper, we present four issues to help people better understand the situations that could occur in the management of incidents with hazards: 1). Evacuation in the presence of hazards; 2). 3D incident management; 3). Navigation support for first responders; 4). Navigation support for road users. To address these issues, we propose a solution which combines agent technology, geo-database, hazard simulation, and traffic simulation. Further research would be needed to investigate the potentials of the proposed solution in real applications.

  20. Traffic Management in ATM Networks Over Satellite Links

    NASA Technical Reports Server (NTRS)

    Goyal, Rohit; Jain, Raj; Goyal, Mukul; Fahmy, Sonia; Vandalore, Bobby; vonDeak, Thomas

    1999-01-01

    This report presents a survey of the traffic management Issues in the design and implementation of satellite Asynchronous Transfer Mode (ATM) networks. The report focuses on the efficient transport of Transmission Control Protocol (TCP) traffic over satellite ATM. First, a reference satellite ATM network architecture is presented along with an overview of the service categories available in ATM networks. A delay model for satellite networks and the major components of delay and delay variation are described. A survey of design options for TCP over Unspecified Bit Rate (UBR), Guaranteed Frame Rate (GFR) and Available Bit Rate (ABR) services in ATM is presented. The main focus is on traffic management issues. Several recommendations on the design options for efficiently carrying data services over satellite ATM networks are presented. Most of the results are based on experiments performed on Geosynchronous (GEO) latencies. Some results for Low Earth Orbits (LEO) and Medium Earth Orbit (MEO) latencies are also provided.

  1. An evolutionary outlook of air traffic flow management techniques

    NASA Astrophysics Data System (ADS)

    Kistan, Trevor; Gardi, Alessandro; Sabatini, Roberto; Ramasamy, Subramanian; Batuwangala, Eranga

    2017-01-01

    In recent years Air Traffic Flow Management (ATFM) has become pertinent even in regions without sustained overload conditions caused by dense traffic operations. Increasing traffic volumes in the face of constrained resources has created peak congestion at specific locations and times in many areas of the world. Increased environmental awareness and economic drivers have combined to create a resurgent interest in ATFM as evidenced by a spate of recent ATFM conferences and workshops mediated by official bodies such as ICAO, IATA, CANSO the FAA and Eurocontrol. Significant ATFM acquisitions in the last 5 years include South Africa, Australia and India. Singapore, Thailand and Korea are all expected to procure ATFM systems within a year while China is expected to develop a bespoke system. Asia-Pacific nations are particularly pro-active given the traffic growth projections for the region (by 2050 half of all air traffic will be to, from or within the Asia-Pacific region). National authorities now have access to recently published international standards to guide the development of national and regional operational concepts for ATFM, geared to Communications, Navigation, Surveillance/Air Traffic Management and Avionics (CNS+A) evolutions. This paper critically reviews the field to determine which ATFM research and development efforts hold the best promise for practical technological implementations, offering clear benefits both in terms of enhanced safety and efficiency in times of growing air traffic. An evolutionary approach is adopted starting from an ontology of current ATFM techniques and proceeding to identify the technological and regulatory evolutions required in the future CNS+A context, as the aviation industry moves forward with a clearer understanding of emerging operational needs, the geo-political realities of regional collaboration and the impending needs of global harmonisation.

  2. Airborne Collision Avoidance Systems and Air Traffic Management Safety

    NASA Astrophysics Data System (ADS)

    Brooker, Peter

    2005-01-01

    A new ICAO Policy on Airborne Collision Avoidance Systems is needed, which recognizes it to be an integrated part of the air traffic management system's safety defences; and that should be fully included in hazard analyses for the total system's design safety targets.

  3. Distributed and Centralized Conflict Management Under Traffic Flow Management Constraints

    NASA Technical Reports Server (NTRS)

    Feron, Eric; Bilimoria, Karl (Technical Monitor)

    2001-01-01

    The past year's activity has concentrated on the following two activities: (1) Refining and completing our study on the stability of interacting flows of aircraft when they have to resolve conflicts in a decentralized and sequential manner. More specifically, it was felt that some of the modeling assumptions made during previous research (such offset maneuvering models) could be improved to include more realistic models such as heading changes when analyzing interacting flow stability problems. We extended our analysis to achieve this goal. The results of this study have been submitted for presentation at the 2002 American Control Conference; (2) Examining the issues associated with delay propagation across multiple enroute sectors. This study was initiated at NASA in cooperation with Dr. Karl Bilimoria. Considering a set of adjacent sectors, this ongoing study concentrates on the effect of various traffic flow management strategies on the propagation of delays and congestion across sectors. The problem description and findings so far are reported in the attached working paper "Enroute sector buffering capacity."

  4. Air traffic control by distributed management in a MLS environment

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.; Parkin, L.; Hart, S.

    1977-01-01

    The microwave landing system (MLS) is a technically feasible means for increasing runway capacity since it could support curved approaches to a short final. The shorter the final segment of the approach, the wider the variety of speed mixes possible so that theoretically, capacity would ultimately be limited by runway occupance time only. An experiment contrasted air traffic control in a MLS environment under a centralized form of management and under distributed management which was supported by a traffic situation display in each of the 3 piloted simulators. Objective flight data, verbal communication and subjective responses were recorded on 18 trial runs lasting about 20 minutes each. The results were in general agreement with previous distributed management research. In particular, distributed management permitted a smaller spread of intercrossing times and both pilots and controllers perceived distributed management as the more 'ideal' system in this task. It is concluded from this and previous research that distributed management offers a viable alternative to centralized management with definite potential for dealing with dense traffic in a safe, orderly and expeditious manner.

  5. Enterprise network control and management: traffic flow models

    NASA Astrophysics Data System (ADS)

    Maruyama, William; George, Mark S.; Hernandez, Eileen; LoPresto, Keith; Uang, Yea

    1999-11-01

    The exponential growth and dramatic increase in demand for network bandwidth is expanding the market for broadband satellite networks. It is critical to rapidly deliver ubiquitous satellite communication networks that are differentiated by lower cost and increased Quality of Service (QoS). There is a need to develop new network architectures, control and management systems to meet the future commercial and military traffic requirements, services and applications. The next generation communication networks must support legacy and emerging network traffic while providing user negotiated levels of QoS. Network resources control algorithms must be designed to provide the guaranteed performance levels for voice, video and data having different service requirements. To evaluate network architectures and performance, it is essential to understand the network traffic characteristics.

  6. 75 FR 61552 - RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... Federal Aviation Administration RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC... Traffic Management Advisory Committee (ATMAC) SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC) DATES:...

  7. 75 FR 39091 - RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-07

    ... Federal Aviation Administration RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC... Traffic Management Advisory Committee (ATMAC). SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Government/Industry Air Traffic Management Advisory Committee (ATMAC)....

  8. An air traffic flow management method based on mixed genetic algorithms

    NASA Astrophysics Data System (ADS)

    Fu, Ying

    2009-12-01

    With the air traffic congest problem becoming more and more severe, the study of air traffic flow management is more and more important. According to the character of air traffic flow management, the author analyzed the heuristic method and genetic algorithms, later put this two method together and give a new method of air traffic flow management-mixture genetic algorithms, It has global convergence, the simulation result demonstrates that the presented algorithm is effective.

  9. A Distributed Trajectory-Oriented Approach to Managing Traffic Complexity

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Wing, David J.; Vivona, Robert; Garcia-Chico, Jose-Luis

    2007-01-01

    In order to handle the expected increase in air traffic volume, the next generation air transportation system is moving towards a distributed control architecture, in which ground-based service providers such as controllers and traffic managers and air-based users such as pilots share responsibility for aircraft trajectory generation and management. While its architecture becomes more distributed, the goal of the Air Traffic Management (ATM) system remains to achieve objectives such as maintaining safety and efficiency. It is, therefore, critical to design appropriate control elements to ensure that aircraft and groundbased actions result in achieving these objectives without unduly restricting user-preferred trajectories. This paper presents a trajectory-oriented approach containing two such elements. One is a trajectory flexibility preservation function, by which aircraft plan their trajectories to preserve flexibility to accommodate unforeseen events. And the other is a trajectory constraint minimization function by which ground-based agents, in collaboration with air-based agents, impose just-enough restrictions on trajectories to achieve ATM objectives, such as separation assurance and flow management. The underlying hypothesis is that preserving trajectory flexibility of each individual aircraft naturally achieves the aggregate objective of avoiding excessive traffic complexity, and that trajectory flexibility is increased by minimizing constraints without jeopardizing the intended ATM objectives. The paper presents conceptually how the two functions operate in a distributed control architecture that includes self separation. The paper illustrates the concept through hypothetical scenarios involving conflict resolution and flow management. It presents a functional analysis of the interaction and information flow between the functions. It also presents an analytical framework for defining metrics and developing methods to preserve trajectory flexibility and

  10. Debris Mitigation as a Component of Space Traffic Management

    NASA Astrophysics Data System (ADS)

    Kemper Force, M.

    2012-01-01

    The necessity of a traffic management in space is a consequence of our "free use" of it over the past fifty years, during which certain orbits have accumulated a significant amount of debris that may, in the future, threaten the feasibility of their use. This paper encapsulates the primary issues involved in the concept of space traffic management through basic questions, using as a case study the recent alarm caused by two close-misses of the ISS in one week, in order to guide the reader to an understanding of the current need for a space traffic management regime. The paper will describe the fundamental elements of space traffic management, including the tracking of objects, conjunction assessment, collision avoidance and orbital mechanics to understand why Earth-bound systems cannot be extrapolated to space. The paper will then focus on the primary concern of space debris, the acceptance and use of current guidelines in light of the existing corpus juris spatialis and international law, positing that the guidelines may soon develop into a customary norm. The paper will conclude that the latest close calls with the ISS demonstrate we cannot count on the mere vastness of space to reduce the probability of collisions with space objects. Despite the significant political, technical and economic challenges recognized by the International Space University Final Report of 2007, the International Academy of Astronautics' Cosmic Study of 2006 and the IAASS An ICAO for Space?, there is a need for a system to obviate the looming peril before governments and investors will sign on to a comprehensive program which limits their "free" use of space.

  11. 75 FR 1116 - RTCA Government/Industry Air Traffic Management Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-08

    .../Industry Air Traffic Management Advisory Committee AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Government/Industry Air Traffic Management Advisory Committee. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Government/Industry Air Traffic...

  12. Financial Management: Military Traffic Management Command Handling of Container Detention Charges

    DTIC Science & Technology

    2007-11-02

    DC 20301-1900. The identity of each writer and caller is fully protected. Acronyms MTMC Military Traffic Management Command Office of...cargo by commercial motor carriers. Background. This report discusses the Military Traffic Management Command ( MTMC ) Operations Directorate handling...of detention charges that motor carriers incurred. MTMC uses DoD-owned intermodal containers, as well as those that the commercial transportation

  13. Design of automation tools for management of descent traffic

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Nedell, William

    1988-01-01

    The design of an automated air traffic control system based on a hierarchy of advisory tools for controllers is described. Compatibility of the tools with the human controller, a key objective of the design, is achieved by a judicious selection of tasks to be automated and careful attention to the design of the controller system interface. The design comprises three interconnected subsystems referred to as the Traffic Management Advisor, the Descent Advisor, and the Final Approach Spacing Tool. Each of these subsystems provides a collection of tools for specific controller positions and tasks. This paper focuses primarily on the Descent Advisor which provides automation tools for managing descent traffic. The algorithms, automation modes, and graphical interfaces incorporated in the design are described. Information generated by the Descent Advisor tools is integrated into a plan view traffic display consisting of a high-resolution color monitor. Estimated arrival times of aircraft are presented graphically on a time line, which is also used interactively in combination with a mouse input device to select and schedule arrival times. Other graphical markers indicate the location of the fuel-optimum top-of-descent point and the predicted separation distances of aircraft at a designated time-control point. Computer generated advisories provide speed and descent clearances which the controller can issue to aircraft to help them arrive at the feeder gate at the scheduled times or with specified separation distances. Two types of horizontal guidance modes, selectable by the controller, provide markers for managing the horizontal flightpaths of aircraft under various conditions. The entire system consisting of descent advisor algorithm, a library of aircraft performance models, national airspace system data bases, and interactive display software has been implemented on a workstation made by Sun Microsystems, Inc. It is planned to use this configuration in operational

  14. Concepts and algorithms for terminal-area traffic management

    NASA Technical Reports Server (NTRS)

    Erzberger, H.; Chapel, J. D.

    1984-01-01

    The nation's air-traffic-control system is the subject of an extensive modernization program, including the planned introduction of advanced automation techniques. This paper gives an overview of a concept for automating terminal-area traffic management. Four-dimensional (4D) guidance techniques, which play an essential role in the automated system, are reviewed. One technique, intended for on-board computer implementation, is based on application of optimal control theory. The second technique is a simplified approach to 4D guidance intended for ground computer implementation. It generates advisory messages to help the controller maintain scheduled landing times of aircraft not equipped with on-board 4D guidance systems. An operational system for the second technique, recently evaluated in a simulation, is also described.

  15. Design and Operational Evaluation of the Traffic Management Advisor at the Ft. Worth Air Route Traffic Control Center

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.; Vincent, Danny; Tobias, Leonard (Technical Monitor)

    1997-01-01

    NASA and the FAA have designed and developed and an automation tool known as the Traffic Management Advisor (TMA). The system was operationally evaluated at the Ft. Worth Air Route Traffic Control Center (ARTCC). The TMA is a time-based strategic planning tool that provides Traffic Management Coordinators and En Route Air Traffic Controllers the ability to efficiently optimize the capacity of a demand impacted airport. The TMA consists of trajectory prediction, constraint-based runway scheduling, traffic flow visualization and controllers advisories. The TMA was used and operationally evaluated for forty-one rush traffic periods during a one month period in the Summer of 1996. The evaluations included all shifts of air traffic operations as well as periods of inclement weather. Performance data was collected for engineering and human factor analysis and compared with similar operations without the TMA. The engineering data indicates that the operations with the TMA show a one to two minute per aircraft delay reduction during rush periods. The human factor data indicate a perceived reduction in en route controller workload as well as an increase in job satisfaction. Upon completion of the evaluation, the TMA has become part of the normal operations at the Ft. Worth ARTCC.

  16. Traffic Management for Emergency Vehicle Priority Based on Visual Sensing

    PubMed Central

    Nellore, Kapileswar; Hancke, Gerhard P.

    2016-01-01

    Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results

  17. Traffic Management for Emergency Vehicle Priority Based on Visual Sensing.

    PubMed

    Nellore, Kapileswar; Hancke, Gerhard P

    2016-11-10

    Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results

  18. Adaptive multibeam concepts for traffic management satellite systems.

    NASA Technical Reports Server (NTRS)

    Bisaga, J. J.; Blank, H. A.; Klein, S. A.

    1973-01-01

    The analysis of the performance of the various implementations of the simultaneous system in the Atlantic and Pacific Oceans has demonstrated that the use of adaptive system concepts in satellite traffic management systems can greatly improve the performance capabilities of these systems as compared to the corresponding performance capabilities of conventional nonadaptive satellite communications systems. It is considered that the techniques developed and analyzed represent a significant technological advance, and that the performance improvement achieved will generally outweigh the increased cost and implementation factors.

  19. The research of highway traffic accident management and pre-alarm system

    NASA Astrophysics Data System (ADS)

    Xu, Jianping; Zhang, Tiejun; Wan, Jiaonan; Zhang, Juwen; Wang, Rui

    For the rigorous traffic safety issues resulting from rapid transportation development, as well as the more and more attention paid to the traffic accidents dynamic analysis and pre-alarm methods, combined with the practical needs of the highway safety management, this paper summarizes the experience of traffic safety pre-alarm research both in domestic and abroad, designs the frame of highway traffic accident management and pre-alarm system from the function and software engineering requirement, and refines kernel modules such as accident prone section judgement, traffic safety pre-alarm analysis and perfecting safety measures analysis, in order to guide the exploitation and application of the system.

  20. Datalink in air traffic management: Human factors issues in communications.

    PubMed

    Stedmon, Alex W; Sharples, Sarah; Littlewood, Robert; Cox, Gemma; Patel, Harshada; Wilson, John R

    2007-07-01

    This paper examines issues underpinning the potential move in aviation away from real speech radiotelephony (R/T) communications towards datalink communications involving text and synthetic speech communications. Using a novel air traffic control (ATC) task, two experiments are reported. Experiment 1 compared the use of speech and text while Experiment 2 compared the use of real and synthetic speech communications. Results indicated that generally there were no significant differences between speech and text communications and that either type could be used without any main effects on performance. However, a number of specific differences were observed across the different phases of the scenarios indicating that workload levels may be more varied when speech communications are used. Experiment 2 illustrated that participants placed a greater level of trust in real speech than synthetic speech, and trusted true communications more than false communications (regardless of whether they were real or synthetic voices). The findings are considered in terms of datalink initiatives for future air traffic management, the importance placed on real speech R/T communications, and the need to develop more natural synthetic speech in this application area.

  1. Acceleration of aircraft-level Traffic Flow Management

    NASA Astrophysics Data System (ADS)

    Rios, Joseph Lucio

    This dissertation describes novel approaches to solving large-scale, high fidelity, aircraft-level Traffic Flow Management scheduling problems. Depending on the methods employed, solving these problems to optimality can take longer than the length of the planning horizon in question. Research in this domain typically focuses on the quality of the modeling used to describe the problem and the benefits achieved from the optimized solution, often treating computational aspects as secondary or tertiary. The work presented here takes the complementary view and considers the computational aspect as the primary concern. To this end, a previously published model for solving this Traffic Flow Management scheduling problem is used as starting point for this study. The model proposed by Bertsimas and Stock-Patterson is a binary integer program taking into account all major resource capacities and the trajectories of each flight to decide which flights should be held in which resource for what amount of time in order to satisfy all capacity requirements. For large instances, the solve time using state-of-the-art solvers is prohibitive for use within a potential decision support tool. With this dissertation, however, it will be shown that solving can be achieved in reasonable time for instances of real-world size. Five other techniques developed and tested for this dissertation will be described in detail. These are heuristic methods that provide good results. Performance is measured in terms of runtime and "optimality gap." We then describe the most successful method presented in this dissertation: Dantzig-Wolfe Decomposition. Results indicate that a parallel implementation of Dantzig-Wolfe Decomposition optimally solves the original problem in much reduced time and with better integrality and smaller optimality gap than any of the heuristic methods or state-of-the-art, commercial solvers. The solution quality improves in every measureable way as the number of subproblems

  2. Development of an air ground data exchange concept: Flight deck perspective

    NASA Technical Reports Server (NTRS)

    Flathers, G. W., II

    1987-01-01

    The planned modernization of the U.S. National Airspace System (NAS) includes the development and use of a digital data link as a means to exchange information between aircraft and ground-based facilities. This report presents an operationally-oriented concept on how data link could be used for applications related directly to air traffic control. The specific goal is to establish the role that data link could play in the air-ground communications. Due regard is given to the unique characteristics of data link and voice communications, current principles of air traffic control, operational procedures, human factors/man-machine interfaces, and the integration of data link with other air and ground systems. The resulting concept is illustrated in the form of a paper-and-pencil simulation in which data link and voice communications during the course of a hypothetical flight are described.

  3. Expanding the Use of Time-Based Metering: Multi-Center Traffic Management Advisor

    NASA Technical Reports Server (NTRS)

    Landry, Steven J.; Farley, Todd; Hoang, Ty

    2005-01-01

    Time-based metering is an efficient air traffic management alternative to the more common practice of distance-based metering (or "miles-in-trail spacing"). Despite having demonstrated significant operational benefit to airspace users and service providers, time-based metering is used in the United States for arrivals to just nine airports and is not used at all for non-arrival traffic flows. The Multi-Center Traffic Management Advisor promises to bring time-based metering into the mainstream of air traffic management techniques. Not constrained to operate solely on arrival traffic, Multi-Center Traffic Management Advisor is flexible enough to work in highly congested or heavily partitioned airspace for any and all traffic flows in a region. This broader and more general application of time-based metering is expected to bring the operational benefits of time-based metering to a much wider pool of beneficiaries than is possible with existing technology. It also promises to facilitate more collaborative traffic management on a regional basis. This paper focuses on the operational concept of the Multi-Center Traffic Management Advisor, touching also on its system architecture, field test results, and prospects for near-term deployment to the United States National Airspace System.

  4. Flight management concepts compatible with air traffic control

    NASA Technical Reports Server (NTRS)

    Morello, S. A.

    1986-01-01

    With the advent of airline deregulation and increased competition, the need for cost efficient airline operations is critical. This paper summarizes past research efforts and planned research thrusts toward the development of compatible flight management and air traffic control systems that promise increased operational effectiveness and efficiency. Potential capacity improvements resulting from a time-based ATC simulation (fast-time) are presented. Advanced display concepts with time guidance and velocity vector information to allow the flight crew to play an important role in the future ATC environment are discussed. Results of parametric sensitivity analyses are also presented that quantify the fuel/cost penalties for idle-thrust mismodeling and wind-modeling errors.

  5. Incorporating User Preferences Within an Optimal Traffic Flow Management Framework

    NASA Technical Reports Server (NTRS)

    Rios, Joseph Lucio; Sheth, Kapil S.; Guiterrez-Nolasco, Sebastian Armardo

    2010-01-01

    The effectiveness of future decision support tools for Traffic Flow Management in the National Airspace System will depend on two major factors: computational burden and collaboration. Previous research has focused separately on these two aspects without consideration of their interaction. In this paper, their explicit combination is examined. It is shown that when user preferences are incorporated with an optimal approach to scheduling, runtime is not adversely affected. A benefit-cost ratio is used to measure the influence of user preferences on an optimal solution. This metric shows user preferences can be accommodated without inordinately, negatively affecting the overall system delay. Specifically, incorporating user preferences will increase delays proportionally to increased user satisfaction.

  6. Road traffic crashes managed by Rescue 1122 in Lahore, Pakistan.

    PubMed

    Tahir, Navid; Naseer, Rizwan; Khan, Samina Mohsin; Macassa, Gloria; Hashmi, Waseem; Durrani, Mohsin

    2012-01-01

    The objective of this retrospective study was to describe demographic characteristics, injury patterns and causes of road traffic crashes (RTCs) managed by Rescue 1122 in Lahore, Pakistan during the period 2005-2010. In total 123,268 RTCs were reported and responded by Rescue 1122 ambulance service during the study period. Of the 132,504 victims of RTCs, there were 67% male and 33% female subjects, and the maximum share (65%) was reported among people aged 16-35 years. Motorcyclists were involved in 45% of crashes, with over-speeding (40%) found to be the major reason of these collisions. Similarly, minor injuries (65%) and fractures (25%) were the most reported outcome of these crashes. It is concluded that data from ambulance services, if appropriately collected, can provide valuable epidemiological information to monitor RTCs in developing countries. However, in Pakistan, the collection of data as well as the registration process needs further improvement.

  7. Analysis of ETMS Data Quality for Traffic Flow Management Decisions

    NASA Technical Reports Server (NTRS)

    Chatterji, Gano B.; Sridhar, Banavar; Kim, Douglas

    2003-01-01

    The data needed for air traffic flow management decision support tools is provided by the Enhanced Traffic Management System (ETMS). This includes both the tools that are in current use and the ones being developed for future deployment. Since the quality of decision support provided by all these tools will be influenced by the quality of the input ETMS data, an assessment of ETMS data quality is needed. Motivated by this desire, ETMS data quality is examined in this paper in terms of the unavailability of flight plans, deviation from the filed flight plans, departure delays, altitude errors and track data drops. Although many of these data quality issues are not new, little is known about their extent. A goal of this paper is to document the magnitude of data quality issues supported by numerical analysis of ETMS data. Guided by this goal, ETMS data for a 24-hour period were processed to determine the number of aircraft with missing flight plan messages at any given instant of time. Results are presented for aircraft above 18,000 feet altitude and also at all altitudes. Since deviation from filed flight plan is also a major cause of trajectory-modeling errors, statistics of deviations are presented. Errors in proposed departure times and ETMS-generated vertical profiles are also shown. A method for conditioning the vertical profiles for improving demand prediction accuracy is described. Graphs of actual sector counts obtained using these vertical profiles are compared with those obtained using the Host data for sectors in the Fort Worth Center to demonstrate the benefit of preprocessing. Finally, results are presented to quantify the extent of data drops. A method for propagating track positions during ETMS data drops is also described.

  8. The Development of the Multi-Center Traffic Management Advisor (MCTMA): Traffic Flow Management Research in a Multi-Facility Environment

    NASA Technical Reports Server (NTRS)

    Lee, Katharine K.; Davis, Thomas J.; Levin, Kerry M.; Rowe, Dennis W.

    2001-01-01

    The Traffic Management Advisor (TMA) is a decision-support tool for traffic managers and air traffic controllers that provides traffic flow visualization and other flow management tools. TMA creates an efficiently sequenced and safely spaced schedule for arrival traffic that meets but does not exceed specified airspace system constraints. TMA is being deployed at selected facilities throughout the National Airspace System in the US as part of the FAA's Free Flight Phase 1 program. TMA development and testing, and its current deployment, focuses on managing the arrival capacity for single major airports within single terminal areas and single en route centers. The next phase of development for this technology is the expansion of the TMA capability to complex facilities in which a terminal area or airport is fed by multiple en route centers, thus creating a multicenter TMA functionality. The focus of the multi-center TMA (McTMA) development is on the busy facilities in the Northeast comdor of the US. This paper describes the planning and development of McTMA and the challenges associated with adapting a successful traffic flow management tool for a very complex airspace.

  9. 47 CFR 22.805 - Channels for general aviation air-ground service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Channels for general aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.805 Channels for general aviation air-ground service. The following channels are...

  10. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  11. 47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Channel plan for commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.857 Channel plan for commercial aviation air-ground systems. The 849-851 MHz and 894-896...

  12. 47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Channel plan for commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.857 Channel plan for commercial aviation air-ground systems. The 849-851 MHz and 894-896...

  13. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  14. 47 CFR 22.859 - Incumbent commercial aviation air-ground systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Incumbent commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.859 Incumbent commercial aviation air-ground systems. This section contains rules...

  15. 47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Channel plan for commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.857 Channel plan for commercial aviation air-ground systems. The 849-851 MHz and 894-896...

  16. 47 CFR 22.859 - Incumbent commercial aviation air-ground systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Incumbent commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.859 Incumbent commercial aviation air-ground systems. This section contains rules...

  17. 47 CFR 22.859 - Incumbent commercial aviation air-ground systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Incumbent commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.859 Incumbent commercial aviation air-ground systems. This section contains rules...

  18. 47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Channel plan for commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.857 Channel plan for commercial aviation air-ground systems. The 849-851 MHz and 894-896...

  19. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  20. 47 CFR 22.859 - Incumbent commercial aviation air-ground systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Incumbent commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.859 Incumbent commercial aviation air-ground systems. This section contains rules...

  1. 47 CFR 22.805 - Channels for general aviation air-ground service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channels for general aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.805 Channels for general aviation air-ground service. The following channels are...

  2. 47 CFR 22.805 - Channels for general aviation air-ground service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Channels for general aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.805 Channels for general aviation air-ground service. The following channels are...

  3. 47 CFR 22.857 - Channel plan for commercial aviation air-ground systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channel plan for commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.857 Channel plan for commercial aviation air-ground systems. The 849-851 MHz and 894-896...

  4. 47 CFR 22.805 - Channels for general aviation air-ground service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Channels for general aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.805 Channels for general aviation air-ground service. The following channels are...

  5. 47 CFR 22.859 - Incumbent commercial aviation air-ground systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Incumbent commercial aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.859 Incumbent commercial aviation air-ground systems. This section contains rules...

  6. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  7. 47 CFR 22.807 - General aviation air-ground application requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false General aviation air-ground application... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.807 General aviation air-ground application requirements. In addition to the...

  8. 47 CFR 22.805 - Channels for general aviation air-ground service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Channels for general aviation air-ground... CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service General Aviation Air-Ground Stations § 22.805 Channels for general aviation air-ground service. The following channels are...

  9. A Multi-Operator Simulation for Investigation of Distributed Air Traffic Management Concepts

    NASA Technical Reports Server (NTRS)

    Peters, Mark E.; Ballin, Mark G.; Sakosky, John S.

    2002-01-01

    This paper discusses the current development of an air traffic operations simulation that supports feasibility research for advanced air traffic management concepts. The Air Traffic Operations Simulation (ATOS) supports the research of future concepts that provide a much greater role for the flight crew in traffic management decision-making. ATOS provides representations of the future communications, navigation, and surveillance (CNS) infrastructure, a future flight deck systems architecture, and advanced crew interfaces. ATOS also provides a platform for the development of advanced flight guidance and decision support systems that may be required for autonomous operations.

  10. Control of Future Air Traffic Systems via Complexity Bound Management

    NASA Technical Reports Server (NTRS)

    Alexandrov, Natalia

    2013-01-01

    The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

  11. Aircraft/Air Traffic Management Functional Analysis Model. Version 2.0; User's Guide

    NASA Technical Reports Server (NTRS)

    Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

    1998-01-01

    The Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 (FAM 2.0), is a discrete event simulation model designed to support analysis of alternative concepts in air traffic management and control. FAM 2.0 was developed by the Logistics Management Institute (LMI) a National Aeronautics and Space Administration (NASA) contract. This document provides a guide for using the model in analysis. Those interested in making enhancements or modification to the model should consult the companion document, Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 Technical Description.

  12. CTAS and NASA Air Traffic Management Fact Sheets for En Route Descent Advisor and Surface Management System

    NASA Technical Reports Server (NTRS)

    Lee, Katharine

    2004-01-01

    The Surface Management System (SMS) is a decision support tool that will help controllers, traffic managers, and NAS users manage the movements of aircraft on the surface of busy airports, improving capacity, efficiency, and flexibility. The Advanced Air Transportation Technologies (AATT) Project at NASA is developing SMS in cooperation with the FAA's Free Flight Phase 2 (FFP2) pro5ram. SMS consists of three parts: a traffic management tool, a controller tool, and a National Airspace System (NAS) information tool.

  13. Wind Prediction Accuracy for Air Traffic Management Decision Support Tools

    NASA Technical Reports Server (NTRS)

    Cole, Rod; Green, Steve; Jardin, Matt; Schwartz, Barry; Benjamin, Stan

    2000-01-01

    The performance of Air Traffic Management and flight deck decision support tools depends in large part on the accuracy of the supporting 4D trajectory predictions. This is particularly relevant to conflict prediction and active advisories for the resolution of conflicts and the conformance with of traffic-flow management flow-rate constraints (e.g., arrival metering / required time of arrival). Flight test results have indicated that wind prediction errors may represent the largest source of trajectory prediction error. The tests also discovered relatively large errors (e.g., greater than 20 knots), existing in pockets of space and time critical to ATM DST performance (one or more sectors, greater than 20 minutes), are inadequately represented by the classic RMS aggregate prediction-accuracy studies of the past. To facilitate the identification and reduction of DST-critical wind-prediction errors, NASA has lead a collaborative research and development activity with MIT Lincoln Laboratories and the Forecast Systems Lab of the National Oceanographic and Atmospheric Administration (NOAA). This activity, begun in 1996, has focussed on the development of key metrics for ATM DST performance, assessment of wind-prediction skill for state of the art systems, and development/validation of system enhancements to improve skill. A 13 month study was conducted for the Denver Center airspace in 1997. Two complementary wind-prediction systems were analyzed and compared to the forecast performance of the then standard 60 km Rapid Update Cycle - version 1 (RUC-1). One system, developed by NOAA, was the prototype 40-km RUC-2 that became operational at NCEP in 1999. RUC-2 introduced a faster cycle (1 hr vs. 3 hr) and improved mesoscale physics. The second system, Augmented Winds (AW), is a prototype en route wind application developed by MITLL based on the Integrated Terminal Wind System (ITWS). AW is run at a local facility (Center) level, and updates RUC predictions based on an

  14. Dynamic stochastic optimization models for air traffic flow management

    NASA Astrophysics Data System (ADS)

    Mukherjee, Avijit

    This dissertation presents dynamic stochastic optimization models for Air Traffic Flow Management (ATFM) that enables decisions to adapt to new information on evolving capacities of National Airspace System (NAS) resources. Uncertainty is represented by a set of capacity scenarios, each depicting a particular time-varying capacity profile of NAS resources. We use the concept of a scenario tree in which multiple scenarios are possible initially. Scenarios are eliminated as possibilities in a succession of branching points, until the specific scenario that will be realized on a particular day is known. Thus the scenario tree branching provides updated information on evolving scenarios, and allows ATFM decisions to be re-addressed and revised. First, we propose a dynamic stochastic model for a single airport ground holding problem (SAGHP) that can be used for planning Ground Delay Programs (GDPs) when there is uncertainty about future airport arrival capacities. Ground delays of non-departed flights can be revised based on updated information from scenario tree branching. The problem is formulated so that a wide range of objective functions, including non-linear delay cost functions and functions that reflect equity concerns can be optimized. Furthermore, the model improves on existing practice by ensuring efficient use of available capacity without necessarily exempting long-haul flights. Following this, we present a methodology and optimization models that can be used for decentralized decision making by individual airlines in the GDP planning process, using the solutions from the stochastic dynamic SAGHP. Airlines are allowed to perform cancellations, and re-allocate slots to remaining flights by substitutions. We also present an optimization model that can be used by the FAA, after the airlines perform cancellation and substitutions, to re-utilize vacant arrival slots that are created due to cancellations. Finally, we present three stochastic integer programming

  15. Free Flight Simulation: An Initial Examination of Air-Ground Integration Issues

    NASA Technical Reports Server (NTRS)

    Lozito, Sandra; McGann, Alison; Cashion, Patricia; Dunbar, Melisa; Mackintosh, Margaret; Dulchinos, Victoria; Jordan, Kevin; Remington, Roger (Technical Monitor)

    2000-01-01

    The concept of "free flight" is intended to emphasize more flexibility for operators in the National Airspace System (RTCA, 1995). This may include the potential for aircraft self-separation. The purpose of this simulation was to begin examining some of the communication and procedural issues associated with self-separation in an integrated air-ground environment. Participants were 10 commercial U.S. flight crews who flew the B747-400 simulator and 10 Denver ARTCC controllers who monitored traffic in an ATC simulation. A prototypic airborne alerting logic and flight deck display features were designed to allow for increased traffic and maneuvering information. Eight different scenarios representing different conflict types were developed. The effects of traffic density (high and low) and different traffic convergence angles (obtuse, acute, and right) were assessed. Conflict detection times were found to be lower for the flight crews in low density compared to high density scenarios. For the controllers, an interaction between density and convergence angle was revealed. Analyses on the controller detection times found longer detection times in the obtuse high density compared to obtuse low density, as well as the shortest detection times in the high density acute angle condition. Maneuvering and communication events are summarized, and a discussion of future research issues is provided.

  16. A Survey on Urban Traffic Management System Using Wireless Sensor Networks.

    PubMed

    Nellore, Kapileswar; Hancke, Gerhard P

    2016-01-27

    Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research.

  17. A Survey on Urban Traffic Management System Using Wireless Sensor Networks

    PubMed Central

    Nellore, Kapileswar; Hancke, Gerhard P.

    2016-01-01

    Nowadays, the number of vehicles has increased exponentially, but the bedrock capacities of roads and transportation systems have not developed in an equivalent way to efficiently cope with the number of vehicles traveling on them. Due to this, road jamming and traffic correlated pollution have increased with the associated adverse societal and financial effect on different markets worldwide. A static control system may block emergency vehicles due to traffic jams. Wireless Sensor networks (WSNs) have gained increasing attention in traffic detection and avoiding road congestion. WSNs are very trendy due to their faster transfer of information, easy installation, less maintenance, compactness and for being less expensive compared to other network options. There has been significant research on Traffic Management Systems using WSNs to avoid congestion, ensure priority for emergency vehicles and cut the Average Waiting Time (AWT) of vehicles at intersections. In recent decades, researchers have started to monitor real-time traffic using WSNs, RFIDs, ZigBee, VANETs, Bluetooth devices, cameras and infrared signals. This paper presents a survey of current urban traffic management schemes for priority-based signalling, and reducing congestion and the AWT of vehicles. The main objective of this survey is to provide a taxonomy of different traffic management schemes used for avoiding congestion. Existing urban traffic management schemes for the avoidance of congestion and providing priority to emergency vehicles are considered and set the foundation for further research. PMID:26828489

  18. Unmanned Aircraft Systems Traffic Management (UTM) Safely Enabling UAS Operations in Low-Altitude Airspace

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.

    2017-01-01

    Conduct research, development and testing to identify airspace operations requirements to enable large-scale visual and beyond visual line of sight UAS operations in the low-altitude airspace. Use build-a-little-test-a-little strategy remote areas to urban areas Low density: No traffic management required but understanding of airspace constraints. Cooperative traffic management: Understanding of airspace constraints and other operations. Manned and unmanned traffic management: Scalable and heterogeneous operations. UTM construct consistent with FAAs risk-based strategy. UTM research platform is used for simulations and tests. UTM offers path towards scalability

  19. Flight Operations Centers: Transforming NextGen Air Traffic Management FOC Study Team Report

    DTIC Science & Technology

    2012-07-01

    Traffic Management FOC Study Team Report 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK...decision processes. The FOC’s role is key to initiating trajectories. The FOC should also play an important role in the Air Traffic Management ...formalize data sharing. Uniform rules for data sharing should be developed that address roles, responsibilities, quality , timing, and

  20. Trajectory-Oriented Approach to Managing Traffic Complexity: Operational Concept and Preliminary Metrics Definition

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Vivona, Robert; Garcia-Chico, Jose L.

    2008-01-01

    This document describes preliminary research on a distributed, trajectory-oriented approach for traffic complexity management. The approach is to manage traffic complexity in a distributed control environment, based on preserving trajectory flexibility and minimizing constraints. In particular, the document presents an analytical framework to study trajectory flexibility and the impact of trajectory constraints on it. The document proposes preliminary flexibility metrics that can be interpreted and measured within the framework.

  1. Kinetic energy management in road traffic injury prevention: a call for action

    PubMed Central

    Khorasani-Zavareh, Davoud; Bigdeli, Maryam; Saadat, Soheil; Mohammadi, Reza

    2015-01-01

    Abstract: By virtue of their variability, mass and speed have important roles in transferring energies during a crash incidence (kinetic energy). The sum of kinetic energy is important in determining an injury severity and that is equal to one half of the vehicle mass multiplied by the square of the vehicle speed. To meet the Vision Zero policy (a traffic safety policy) prevention activities should be focused on vehicle speed management. Understanding the role of kinetic energy will help to develop measures to reduce the generation, distribution, and effects of this energy during a road traffic crash. Road traffic injury preventive activities necessitate Kinetic energy management to improve road user safety. PMID:24284810

  2. Pilot Preference, Compliance, and Performance With an Airborne Conflict Management Toolset

    NASA Technical Reports Server (NTRS)

    Doble, Nathan A.; Barhydt, Richard; Krishnamurthy, Karthik

    2005-01-01

    A human-in-the-loop experiment was conducted at the NASA Ames and Langley Research Centers, investigating the En Route Free Maneuvering component of a future air traffic management concept termed Distributed Air/Ground Traffic Management (DAG-TM). NASA Langley test subject pilots used the Autonomous Operations Planner (AOP) airborne toolset to detect and resolve traffic conflicts, interacting with subject pilots and air traffic controllers at NASA Ames. Experimental results are presented, focusing on conflict resolution maneuver choices, AOP resolution guidance acceptability, and performance metrics. Based on these results, suggestions are made to further improve the AOP interface and functionality.

  3. The Challenges of Field Testing the Traffic Management Advisor (TMA) in an Operational Air Traffic Control Facility

    NASA Technical Reports Server (NTRS)

    Hoang, Ty; Swenson, Harry N.

    1997-01-01

    The Traffic Management Advisor (TMA), the sequence and schedule tool of the Center/TRACON Automation System (CTAS), was evaluated at the Fort Worth Center (ZFW) in the summer of 1996. This paper describes the challenges encountered during the various phases of the TMA field evaluation, which included system (hardware and software) installation, personnel training, and data collection. Operational procedures were developed and applied to the evaluation process that would ensure air safety. The five weeks of field evaluation imposed minimal impact on the hosting facility and provided valuable engineering and human factors data. The collection of data was very much an opportunistic affair, due to dynamic traffic conditions. One measure of the success of the TMA evaluation is that, rather than remove TMA after the evaluation until it could be fully implemented, the prototype TMA is in continual use at ZFW as the fully operational version is readied for implementation.

  4. Improving Air-Ground Operations on the Complex Battlefield

    DTIC Science & Technology

    2013-03-01

    camera systems , Ground/Vehicle Laser Locator Designator (G/VLLD) and Long Range Advanced Scout Surveillance Systems (LRAS3), and radar systems that...meet the requirements of the future Joint Force, the Army must develop an organic capability to coordinate and execute air-ground operations. The...attack solutions in order to defeat an elusive enemy and minimize collateral damage. In order to meet the requirements of the future Joint Force, the Army

  5. Impact and uncertainty of a traffic management intervention: population exposure to polycyclic aromatic hydrocarbons.

    PubMed

    Vardoulakis, Sotiris; Chalabi, Zaid; Fletcher, Tony; Grundy, Chris; Leonardi, Giovanni S

    2008-05-15

    In urban areas, road traffic is a major source of carcinogenic polycyclic aromatic hydrocarbons (PAH), thus any changes in traffic patterns are expected to affect PAH concentrations in ambient air. Exposure to PAH and other traffic-related air pollutants has often been quantified in a deterministic manner that disregards the various sources of uncertainty in the modelling systems used. In this study, we developed a generic method for handling uncertainty in population exposure models. The method was applied to quantify the uncertainty in population exposure to benzo[a]pyrene (BaP) before and after the implementation of a traffic management intervention. This intervention would affect the movement of vehicles in the studied area and consequently alter traffic emissions, pollutant concentrations and population exposure. Several models, including an emission calculator, a dispersion model and a Geographic Information System were used to quantify the impact of the traffic management intervention. We established four exposure zones defined by distance of residence postcode centroids from major road or intersection. A stochastic method was used to quantify the uncertainty in the population exposure model. The method characterises uncertainty using probability measures and propagates it applying Monte Carlo analysis. The overall model predicted that the traffic management scheme would lead to a minor reduction in mean population exposure to BaP in the studied area. However, the uncertainty associated with the exposure estimates was much larger than this reduction. The proposed method is generic and provides realistic estimates of population exposure to traffic-related pollutants, as well as characterises the uncertainty in these estimates. This method can be used within a decision support tool to evaluate the impact of alternative traffic management policies.

  6. Controller Strategies for Managing Air Traffic in High Altitude Arrival Sectors

    NASA Technical Reports Server (NTRS)

    Smith, Nancy; Palmer, Everett; Prevot, Thomas

    1998-01-01

    Substantial increases in the volume of air traffic in the National Airspace System (NAS) are forecast for the next decade, with the number of passengers travelling on U.S. airlines expected to increase by as much as 60%. This increased demand on system capacity will be accompanied by increases in traffic complexity as air traffic service providers routinely accommodate user preferred routing requests. Changes to the NAS to meet these new demands are currently underway, including development of new decision support tools to aid controllers in monitoring and managing air traffic, and increased air-to-air and air-to-ground information exchange. Changes in roles and responsibilities of pilots and controllers in flight path management will accompany these changes in traffic patterns and information technology, however the ultimate responsibility for maintaining aircraft separation will remain with the air traffic controller. A thorough understanding of the methods controllers use to manage air traffic will help ensure that changes to the NAS are implemented in a way that maintains the controller's ability to separate aircraft as the system evolves. This presentation describes the strategies controllers use today to manage arrival traffic in its descent from cruise altitude to the Terminal Radar Approach Control (TRACON) boundary. Factors that increase the complexity of this task include the presence of overflight traffic, varying aircraft performance characteristics, winds aloft, ground speed variations with altitude, the need to merge arrival traffic into a single stream, and, when arrival traffic exceeds airport runway capacity, the added task of metering flow into the TRACON. Because of the limited information available to controllers to manage arrival traffic, their strategies are often driven by the need to reduce the task's complexity, which can result in de-optimized flight paths for individual aircraft (e.g., sub-optimal descent or speed profiles). Understanding

  7. 47 CFR 22.881 - Air-Ground Radiotelephone Service subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air... exclusive initial applications for general aviation Air-Ground Radiotelephone Service licenses and mutually exclusive initial applications for commercial Air-Ground Radiotelephone Service licenses are subject...

  8. 47 CFR 22.881 - Air-Ground Radiotelephone Service subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Air-Ground Radiotelephone Service Commercial Aviation Air... exclusive initial applications for general aviation Air-Ground Radiotelephone Service licenses and mutually exclusive initial applications for commercial Air-Ground Radiotelephone Service licenses are subject...

  9. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  10. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  11. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  12. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  13. 47 CFR 22.873 - Construction requirements for commercial aviation air-ground systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... aviation air-ground systems. 22.873 Section 22.873 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... Aviation Air-Ground Systems § 22.873 Construction requirements for commercial aviation air-ground systems. Licensees authorized to use more than one megahertz (1 MHz) of the 800 MHz commercial aviation...

  14. Roads and traffic: Effects on ecology and wildlife habitat use; applications for cooperative adaptive management

    USGS Publications Warehouse

    Ouren, Douglas S.; Watts, Raymond D.

    2005-01-01

    The land of the United States in dissected by more than 4 million miles of roads that fragment wildlife habitat on both public and private lands. Traffic on these roads causes additional effects. On secondary roads, which provide access to the most natural habitat, the levels, timing, and types of traffic are seldom known. In order to understand the effects of traffic on wildlife, USGS is conducting research cooperatively with the Bureau of Land Management, the U.S. Forest Service, the National Park Service, and the Colorado Division of Wildlife.

  15. Managing emergencies and abnormal situations in air traffic control (part I): taskwork strategies.

    PubMed

    Malakis, Stathis; Kontogiannis, Tom; Kirwan, Barry

    2010-07-01

    A lot of research in Air Traffic Control (ATC) has focused on human errors in decision making whilst little attention has been paid to the cognitive strategies employed by controllers in managing abnormal situations. This study looks into cognitive strategies in taskwork that enable controllers to become resilient decision-makers. Two field studies were carried out where novice and experienced controllers were observed in simulator training in emergency and unusual scenarios. A prototype model of taskwork strategies in air traffic management was developed and its construct validity was tested in the context of the field studies. A companion study (part II), follows that investigates aspects of teamwork in the same field and contributes to the development of a generic model of Taskwork & Teamwork strategies in Emergencies in Air traffic Management (T(2)EAM). The final section addresses the difficulties experienced by novice controllers and explains taskwork strategies employed by experts to manage uncertainty and balance workload in simulator emergencies.

  16. Aircraft/Air Traffic Management Functional Analysis Model: Technical Description. 2.0

    NASA Technical Reports Server (NTRS)

    Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

    1998-01-01

    The Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 (FAM 2.0), is a discrete event simulation model designed to support analysis of alternative concepts in air traffic management and control. FAM 2.0 was developed by the Logistics Management Institute (LMI) under a National Aeronautics and Space Administration (NASA) contract. This document provides a technical description of FAM 2.0 and its computer files to enable the modeler and programmer to make enhancements or modifications to the model. Those interested in a guide for using the model in analysis should consult the companion document, Aircraft/Air Traffic Management Functional Analysis Model, Version 2.0 Users Manual.

  17. Developing a Minimum Data Set for an Information Management System to Study Traffic Accidents in Iran

    PubMed Central

    Mohammadi, Ali; Ahmadi, Maryam; Gharagozlu, Alireza

    2016-01-01

    Background: Each year, around 1.2 million people die in the road traffic incidents. Reducing traffic accidents requires an exact understanding of the risk factors associated with traffic patterns and behaviors. Properly analyzing these factors calls for a comprehensive system for collecting and processing accident data. Objectives: The aim of this study was to develop a minimum data set (MDS) for an information management system to study traffic accidents in Iran. Materials and Methods: This descriptive, cross-sectional study was performed in 2014. Data were collected from the traffic police, trauma centers, medical emergency centers, and via the internet. The investigated resources for this study were forms, databases, and documents retrieved from the internet. Forms and databases were identical, and one sample of each was evaluated. The related internet-sourced data were evaluated in their entirety. Data were collected using three checklists. In order to arrive at a consensus about the data elements, the decision Delphi technique was applied using questionnaires. The content validity and reliability of the questionnaires were assessed by experts’ opinions and the test-retest method, respectively. Results: An (MDS) of a traffic accident information management system was assigned to three sections: a minimum data set for traffic police with six classes, including 118 data elements; a trauma center with five data classes, including 57 data elements; and a medical emergency center, with 11 classes, including 64 data elements. Conclusions: Planning for the prevention of traffic accidents requires standardized data. As the foundation for crash prevention efforts, existing standard data infrastructures present policymakers and government officials with a great opportunity to strengthen and integrate existing accident information systems to better track road traffic injuries and fatalities. PMID:27247791

  18. Intuitiveness of Symbol Features for Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Ngo, Mary Kim; Vu, Kim-Phuong L.; Thorpe, Elaine; Battiste, Vernol; Strybel, Thomas Z.

    2012-01-01

    We present the results of two online surveys asking participants to indicate what type of air traffic information might be conveyed by a number of symbols and symbol features (color, fill, text, and shape). The results of this initial study suggest that the well-developed concepts of ownership, altitude, and trajectory are readily associated with certain symbol features, while the relatively novel concept of equipage was not clearly associated with any specific symbol feature.

  19. Human-Centered Technologies and Procedures for Future Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Smith, Philip; Woods, David; McCoy, Elaine; Billings, Charles; Sarter, Nadine; Denning, Rebecca; Dekker, Sidney

    1997-01-01

    The use of various methodologies to predict the impact of future Air Traffic Management (ATM) concepts and technologies is explored. The emphasis has been on the importance of modeling coordination and cooperation among multiple agents within this system, and on understanding how the interactions among these agents will be influenced as new roles, responsibilities, procedures and technologies are introduced. To accomplish this, we have been collecting data on performance under the current air traffic management system, identifying critical problem areas and looking for examples suggestive of general approaches for solving such problems. Using the results of these field studies, we have developed a set of concrete scenarios centered around future designs, and have studied performance in these scenarios with a set of 40 controllers, dispatchers, pilots and traffic managers.

  20. Verbal workload in distributed air traffic management. [considering pilot controller interaction

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.; Pardo, B.; Wempe, T. E.; Huff, E.

    1975-01-01

    The effects of alternative traffic management possibilities on task performance and pilot controller verbal workloads were studied. Two new rule structures - sequencing and advisory - in addition to vectoring were studied in conjunction with CRT pilot displays incorporating traffic situation displays with and without aircraft flight path predictors. The sequencing and advisory systems gave increasing control responsibility to the pilots. It was concluded that distributed management systems could in practice significantly reduce controller verbal workload without reducing system performance. Implications of this conclusion suggest that distributed management would allow controllers to handle a larger volume of traffic safely either as a normal operating procedure or as a failure mode alternative in a highly automated ground centered system.

  1. Time-based air traffic management using expert systems

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Scoggins, J. L.

    1986-01-01

    A prototype expert system has been developed for the time scheduling of aircraft into the terminal area. The three functions of the air-traffic-control schedule advisor are as follows: (1) for each new arrival, it develops an admisible flight plan for that aircraft; (2) as the aircraft progresses through the terminal area, it monitors deviations from the aircraft's flight plan and provides advisories to return the aircraft to its assigned schedule; and (3) if major disruptions such as missed approaches occur, it develops a revised plan. The advisor is operational on a Symbolics 3600, and is programmed in MRS (a logic programming language), Lisp, and Fortran.

  2. Time-based air traffic management using expert systems

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Scoggins, J. L.

    1986-01-01

    A prototype expert system was developed for the time scheduling of aircraft into the terminal area. The three functions of the air traffic control schedule advisor are as follows: first, for each new arrival, it develops an admissible flight plan for that aircraft. Second, as the aircraft progresses through the terminal area, it monitors deviations from the flight plan and provides advisories to return the aircraft to its assigned schedule. Third, if major disruptions such as missed approaches occur, it develops a revised plan. The advisor is operational on a Symbolics 3600, and is programed in MRS (a logic programming language), Lisp, and FORTRAN.

  3. A Near-Term Concept for Trajectory Based Operations with Air/Ground Data Link Communication

    NASA Technical Reports Server (NTRS)

    McNally, David; Mueller, Eric; Thipphavong, David; Paielli, Russell; Cheng, Jinn-Hwei; Lee, Chuhan; Sahlman, Scott; Walton, Joe

    2010-01-01

    An operating concept and required system components for trajectory-based operations with air/ground data link for today's en route and transition airspace is proposed. Controllers are fully responsible for separation as they are today, and no new aircraft equipage is required. Trajectory automation computes integrated solutions to problems like metering, weather avoidance, traffic conflicts and the desire to find and fly more time/fuel efficient flight trajectories. A common ground-based system supports all levels of aircraft equipage and performance including those equipped and not equipped for data link. User interface functions for the radar controller's display make trajectory-based clearance advisories easy to visualize, modify if necessary, and implement. Laboratory simulations (without human operators) were conducted to test integrated operation of selected system components with uncertainty modeling. Results are based on 102 hours of Fort Worth Center traffic recordings involving over 37,000 individual flights. The presence of uncertainty had a marginal effect (5%) on minimum-delay conflict resolution performance, and windfavorable routes had no effect on detection and resolution metrics. Flight plan amendments and clearances were substantially reduced compared to today s operations. Top-of-descent prediction errors are the largest cause of failure indicating that better descent predictions are needed to reliably achieve fuel-efficient descent profiles in medium to heavy traffic. Improved conflict detections for climbing flights could enable substantially more continuous climbs to cruise altitude. Unlike today s Conflict Alert, tactical automation must alert when an altitude amendment is entered, but before the aircraft starts the maneuver. In every other failure case tactical automation prevented losses of separation. A real-time prototype trajectory trajectory-automation system is running now and could be made ready for operational testing at an en route

  4. Defining the drivers for accepting decision making automation in air traffic management.

    PubMed

    Bekier, Marek; Molesworth, Brett R C; Williamson, Ann

    2011-04-01

    Air Traffic Management (ATM) operators are under increasing pressure to improve the efficiency of their operation to cater for forecasted increases in air traffic movements. One solution involves increasing the utilisation of automation within the ATM system. The success of this approach is contingent on Air Traffic Control Operators' (ATCOs) willingness to accept increased levels of automation. The main aim of the present research was to examine the drivers underpinning ATCOs' willingness to accept increased utilisation of automation within their role. Two fictitious scenarios involving the application of two new automated decision-making tools were created. The results of an online survey revealed traditional predictors of automation acceptance such as age, trust and job satisfaction explain between 4 and 7% of the variance. Furthermore, these predictors varied depending on the purpose in which the automation was to be employed. These results are discussed from an applied and theoretical perspective. STATEMENT OF RELEVANCE: Efficiency improvements in ATM are required to cater for forecasted increases in air traffic movements. One solution is to increase the utilisation of automation within Air Traffic Control. The present research examines the drivers underpinning air traffic controllers' willingness to accept increased levels of automation in their role.

  5. NASA UAS Traffic Management National Campaign Operations across Six UAS Test Sites

    NASA Technical Reports Server (NTRS)

    Rios, Joseph; Mulfinger, Daniel; Homola, Jeff; Venkatesan, Priya

    2016-01-01

    NASA's Unmanned Aircraft Systems Traffic Management research aims to develop policies, procedures, requirements, and other artifacts to inform the implementation of a future system that enables small drones to access the low altitude airspace. In this endeavor, NASA conducted a geographically diverse flight test in conjunction with the FAA's six unmanned aircraft systems Test Sites. A control center at NASA Ames Research Center autonomously managed the airspace for all participants in eight states as they flew operations (both real and simulated). The system allowed for common situational awareness across all stakeholders, kept traffic procedurally separated, offered messages to inform the participants of activity relevant to their operations. Over the 3- hour test, 102 flight operations connected to the central research platform with 17 different vehicle types and 8 distinct software client implementations while seamlessly interacting with simulated traffic.

  6. Report on the Audit of Routing of DoD Freight Shipments by the Military Traffic Management Command

    DTIC Science & Technology

    2007-11-02

    total freight transportation cost), was required to be routed by the Military Traffic Management Command ( MTMC ). The remaining 1.13 million shipments...single manager operating agency for military traffic, land transportation, and common-user ocean terminals, MTMC is responsible for directing

  7. Research of Traffic Management in Fttx Optical Communication Systems

    NASA Astrophysics Data System (ADS)

    Bobrovs, V.; Jelinskis, J.; Ivanovs, G.; Lauks, G.

    2009-01-01

    The paper presents an overview of widely accepted passive optical networks (PONs), and provides the results of comparative OPTSIM simulation for PON technological facilities involving optical layers, with the aim to reveal fiber-to-the-x (FTTx) technologic solutions. Traffic load is simulated over a PON optical layer using the OPNET Modeler to determine potential advantages and drawbacks of the proposed FTTx solution with PON elements in the access networks. The authors show that the optimal transmission speed for PON FTTx would lie in the range 1.25-5.0 Gbit/s with a standard PON architecture, which could be raised to 10 Gbit/s, however in this case we have to change the end user's equipment. In standards that specify the PON's functionality two distances: 10 km and 20 km are indicated. Our simulation shows that, after upgrading the receiver electrical filter, 10 Gbit/s transmissions over 40 km could be reached.

  8. A novel fair active queue management algorithm based on traffic delay jitter

    NASA Astrophysics Data System (ADS)

    Wang, Xue-Shun; Yu, Shao-Hua; Dai, Jin-You; Luo, Ting

    2009-11-01

    In order to guarantee the quantity of data traffic delivered in the network, congestion control strategy is adopted. According to the study of many active queue management (AQM) algorithms, this paper proposes a novel active queue management algorithm named JFED. JFED can stabilize queue length at a desirable level by adjusting output traffic rate and adopting a reasonable calculation of packet drop probability based on buffer queue length and traffic jitter; and it support burst packet traffic through the packet delay jitter, so that it can traffic flow medium data. JFED impose effective punishment upon non-responsible flow with a full stateless method. To verify the performance of JFED, it is implemented in NS2 and is compared with RED and CHOKe with respect to different performance metrics. Simulation results show that the proposed JFED algorithm outperforms RED and CHOKe in stabilizing instantaneous queue length and in fairness. It is also shown that JFED enables the link capacity to be fully utilized by stabilizing the queue length at a desirable level, while not incurring excessive packet loss ratio.

  9. Military Curricula for Vocational and Technical Education. Traffic Management and Accident Investigation, 17-8.

    ERIC Educational Resources Information Center

    Air Force, Washington, DC.

    This teaching guide and student workbook for a postsecondary level course in traffic management and accident investigation is one of a number of military-developed curriculum packages selected for adaptation to vocational instruction and curriculum development in a civilian setting. Purpose stated for the 132-hour course is to expose students to…

  10. Systems Engineering Management Plan NASA Traffic Aware Planner Integration Into P-180 Airborne Test-Bed

    NASA Technical Reports Server (NTRS)

    Maris, John

    2015-01-01

    NASA's Traffic Aware Planner (TAP) is a cockpit decision support tool that provides aircrew with vertical and lateral flight-path optimizations with the intent of achieving significant fuel and time savings, while automatically avoiding traffic, weather, and restricted airspace conflicts. A key step towards the maturation and deployment of TAP concerned its operational evaluation in a representative flight environment. This Systems Engineering Management Plan (SEMP) addresses the test-vehicle design, systems integration, and flight-test planning for the first TAP operational flight evaluations, which were successfully completed in November 2013. The trial outcomes are documented in the Traffic Aware Planner (TAP) flight evaluation paper presented at the 14th AIAA Aviation Technology, Integration, and Operations Conference, Atlanta, GA. (AIAA-2014-2166, Maris, J. M., Haynes, M. A., Wing, D. J., Burke, K. A., Henderson, J., & Woods, S. E., 2014).

  11. Traffic Flow Management Using Aggregate Flow Models and the Development of Disaggregation Methods

    NASA Technical Reports Server (NTRS)

    Sun, Dengfeng; Sridhar, Banavar; Grabbe, Shon

    2010-01-01

    A linear time-varying aggregate traffic flow model can be used to develop Traffic Flow Management (tfm) strategies based on optimization algorithms. However, there are no methods available in the literature to translate these aggregate solutions into actions involving individual aircraft. This paper describes and implements a computationally efficient disaggregation algorithm, which converts an aggregate (flow-based) solution to a flight-specific control action. Numerical results generated by the optimization method and the disaggregation algorithm are presented and illustrated by applying them to generate TFM schedules for a typical day in the U.S. National Airspace System. The results show that the disaggregation algorithm generates control actions for individual flights while keeping the air traffic behavior very close to the optimal solution.

  12. Managing emergencies and abnormal situations in air traffic control (part II): teamwork strategies.

    PubMed

    Malakis, Stathis; Kontogiannis, Tom; Kirwan, Barry

    2010-07-01

    Team performance has been studied in many safety-critical organizations including aviation, nuclear power plant, offshore oil platforms and health organizations. This study looks into teamwork strategies that air traffic controllers employ to manage emergencies and abnormal situations. Two field studies were carried out in the form of observations of simulator training in emergency and unusual scenarios of novices and experienced controllers. Teamwork strategies covered aspects of team orientation and coordination, information exchange, change management and error handling. Several performance metrics were used to rate the efficiency of teamwork and test the construct validity of a prototype model of teamwork. This is a companion study to an earlier investigation of taskwork strategies in the same field (part I) and contributes to the development of a generic model for Taskwork and Teamwork strategies in Emergencies in Air traffic Management (T(2)EAM). Suggestions are made on how to use T(2)EAM to develop training programs, assess team performance and improve mishap investigations.

  13. Development of an Interval Management Algorithm Using Ground Speed Feedback for Delayed Traffic

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan E.; Swieringa, Kurt A.; Underwood, Matthew C.; Abbott, Terence; Leonard, Robert D.

    2016-01-01

    One of the goals of NextGen is to enable frequent use of Optimized Profile Descents (OPD) for aircraft, even during periods of peak traffic demand. NASA is currently testing three new technologies that enable air traffic controllers to use speed adjustments to space aircraft during arrival and approach operations. This will allow an aircraft to remain close to their OPD. During the integration of these technologies, it was discovered that, due to a lack of accurate trajectory information for the leading aircraft, Interval Management aircraft were exhibiting poor behavior. NASA's Interval Management algorithm was modified to address the impact of inaccurate trajectory information and a series of studies were performed to assess the impact of this modification. These studies show that the modification provided some improvement when the Interval Management system lacked accurate trajectory information for the leading aircraft.

  14. Decision support for vessel traffic service (VTS): user needs for dynamic risk management in the VTS.

    PubMed

    Praetorius, Gesa; Lützhöft, Margareta

    2012-01-01

    Vessel Traffic Service (VTS) is a shore-side service implemented by a "Competent Authority to improve the safety and efficiency of vessel traffic and to protect the environment". It is a service that operates through VTS centers, from which VTS operators monitor traffic, assist in navigational matters and provide information to all ships in a designated area. As VTS is provided by operators located on shore, they usually make use of several decision support systems to be able to monitor the traffic and to provide information to the vessels. Although several new tools and approaches have been introduced in the VTS domain, there is still room for improvements. This paper summarizes the results from three studies conducted within the EfficienSea project to approach user needs for dynamic risk management in the VTS domain. Data was collected by conducting study visits and observations at VTS centers, a focus group interview as well as several semi-structured interviews. The paper summarizes the results and presents technical and organizational user needs for dynamic risk management within the VTS domain.

  15. The European air traffic management response to volcanic ash crises: towards institutionalised aviation crisis management.

    PubMed

    Dopagne, Jacques

    2011-06-01

    A cloud of ash drifting from the erupting Eyjafjallajökull volcano in Iceland in April and May 2010 covered Europe and created an unprecedented situation. It resulted in an almost complete lockdown of European airspace in the period from 15th to 21st April, 2010: more than 100,000 flights were cancelled, 10 million people were affected and over US$1.8bn was lost by airlines globally. This paper presents the air traffic management (ATM) view of the situation. Through an analysis of the evolution of the events in the affected region, the paper will provide more details on ATM planning, reaction and follow-up actions. Furthermore, the influence of this event on the identification of further improvements needed to advance volcanic procedures internationally will be discussed. Actions undertaken since the end of the event - the establishment of the European Aviation Crisis Coordination Cell, running of the International Civil Aviation Organization VOLCEX 11/01 volcanic ash exercise and European response to the Grimsvötn eruption in May 2011 - will be discussed at the end of the paper.

  16. Traffic Management Coordinator Evaluation of the Dynamic Weather Routes Concept and System

    NASA Technical Reports Server (NTRS)

    Gong, Chester

    2014-01-01

    Dynamic Weather Routes (DWR) is a weather-avoidance system for airline dispatchers and FAA traffic managers that continually searches for and advises the user of more efficient routes around convective weather. NASA and American Airlines (AA) have been conducting an operational trial of DWR since July 17, 2012. The objective of this evaluation is to assess DWR from a traffic management coordinator (TMC) perspective, using recently retired TMCs and actual DWR reroutes advisories that were rated acceptable by AA during the operational trial. Results from the evaluation showed that the primary reasons for a TMC to modify or reject airline reroute requests were related to airspace configuration. Approximately 80 percent of the reroutes evaluated required some coordination before implementation. Analysis showed TMCs approved 62 percent of the requested DWR reroutes, resulting in 57 percent of the total requested DWR time savings.

  17. Digital map and spatial database requirements for advanced traffic management systems

    SciTech Connect

    Lerner-Lam, E.; Smith, W.T.; Francisca, J.R.; Rathi, A.

    1993-12-31

    Advanced Traffic Management Systems (ATMS) depend on good-quality digital maps and spatial databases. Concerns over the availability of digital maps and spatial databases for ATMS`s in the United States were initially raised in early meetings of IVHS America ATMS committee. While there has been little argument regarding the important role of the private sector in providing ``value-added`` data for sale to public and private parties, the IVHS community has since been engaged in a lively debate over the appropriates roles of the public and private sectors in providing ``base data`` for the nation`s Intelligent Vehicle and Highway Systems. This paper summarizes the activities of the ATMS Committee over the past 1 1/2 years and offers recommendations for next steps to be taken toward laying the foundations for efficient and effective deployment of digital map and spatial database resources for use in advanced traffic management systems.

  18. Complexity analysis of the Next Gen Air Traffic Management System: trajectory based operations.

    PubMed

    Lyons, Rhonda

    2012-01-01

    According to Federal Aviation Administration traffic predictions currently our Air Traffic Management (ATM) system is operating at 150 percent capacity; forecasting that within the next two decades, the traffic with increase to a staggering 250 percent [17]. This will require a major redesign of our system. Today's ATM system is complex. It is designed to safely, economically, and efficiently provide air traffic services through the cost-effective provision of facilities and seamless services in collaboration with multiple agents however, contrary the vision, the system is loosely integrated and is suffering tremendously from antiquated equipment and saturated airways. The new Next Generation (Next Gen) ATM system is designed to transform the current system into an agile, robust and responsive set of operations that are designed to safely manage the growing needs of the projected increasingly complex, diverse set of air transportation system users and massive projected worldwide traffic rates. This new revolutionary technology-centric system is dynamically complex and is much more sophisticated than it's soon to be predecessor. ATM system failures could yield large scale catastrophic consequences as it is a safety critical system. This work will attempt to describe complexity and the complex nature of the NextGen ATM system and Trajectory Based Operational. Complex human factors interactions within Next Gen will be analyzed using a proposed dual experimental approach designed to identify hazards, gaps and elicit emergent hazards that would not be visible if conducted in isolation. Suggestions will be made along with a proposal for future human factors research in the TBO safety critical Next Gen environment.

  19. Airborne Separation Assurance and Traffic Management: Research of Concepts and Technology

    NASA Technical Reports Server (NTRS)

    Ballin, Mark G.; Wing, David J.; Hughes, Monica F.; Conway, Sheila R.

    1999-01-01

    To support the need for increased flexibility and capacity in the future National Airspace System, NASA is pursuing an approach that distributes air traffic separation and management tasks to both airborne and ground-based systems. Details of the distributed operations and the benefits and technical challenges of such a system are discussed. Technology requirements and research issues are outlined, and NASA s approach for establishing concept feasibility, which includes development of the airborne automation necessary to support the concept, is described.

  20. How Formal Methods Impels Discovery: A Short History of an Air Traffic Management Project

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Hagen, George; Maddalon, Jeffrey M.; Munoz, Cesar A.; Narkawicz, Anthony; Dowek, Gilles

    2010-01-01

    In this paper we describe a process of algorithmic discovery that was driven by our goal of achieving complete, mechanically verified algorithms that compute conflict prevention bands for use in en route air traffic management. The algorithms were originally defined in the PVS specification language and subsequently have been implemented in Java and C++. We do not present the proofs in this paper: instead, we describe the process of discovery and the key ideas that enabled the final formal proof of correctness

  1. Analysis of a Dynamic Multi-Track Airway Concept for Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Smith, Jeremy C.; Ballin, Mark G.

    2008-01-01

    The Dynamic Multi-track Airways (DMA) Concept for Air Traffic Management (ATM) proposes a network of high-altitude airways constructed of multiple, closely spaced, parallel tracks designed to increase en-route capacity in high-demand airspace corridors. Segregated from non-airway operations, these multi-track airways establish high-priority traffic flow corridors along optimal routes between major terminal areas throughout the National Airspace System (NAS). Air traffic controllers transition aircraft equipped for DMA operations to DMA entry points, the aircraft use autonomous control of airspeed to fly the continuous-airspace airway and achieve an economic benefit, and controllers then transition the aircraft from the DMA exit to the terminal area. Aircraft authority within the DMA includes responsibility for spacing and/or separation from other DMA aircraft. The DMA controller is responsible for coordinating the entry and exit of traffic to and from the DMA and for traffic flow management (TFM), including adjusting DMA routing on a daily basis to account for predicted weather and wind patterns and re-routing DMAs in real time to accommodate unpredicted weather changes. However, the DMA controller is not responsible for monitoring the DMA for traffic separation. This report defines the mature state concept, explores its feasibility and performance, and identifies potential benefits. The report also discusses (a) an analysis of a single DMA, which was modeled within the NAS to assess capacity and determine the impact of a single DMA on regional sector loads and conflict potential; (b) a demand analysis, which was conducted to determine likely city-pair candidates for a nationwide DMA network and to determine the expected demand fraction; (c) two track configurations, which were modeled and analyzed for their operational characteristic; (d) software-prototype airborne capabilities developed for DMA operations research; (e) a feasibility analysis of key attributes in

  2. Evaluation of the Monotonic Lagrangian Grid and Lat-Long Grid for Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Kaplan, Carolyn; Dahm, Johann; Oran, Elaine; Alexandrov, Natalia; Boris, Jay

    2011-01-01

    The Air Traffic Monotonic Lagrangian Grid (ATMLG) is used to simulate a 24 hour period of air traffic flow in the National Airspace System (NAS). During this time period, there are 41,594 flights over the United States, and the flight plan information (departure and arrival airports and times, and waypoints along the way) are obtained from an Federal Aviation Administration (FAA) Enhanced Traffic Management System (ETMS) dataset. Two simulation procedures are tested and compared: one based on the Monotonic Lagrangian Grid (MLG), and the other based on the stationary Latitude-Longitude (Lat- Long) grid. Simulating one full day of air traffic over the United States required the following amounts of CPU time on a single processor of an SGI Altix: 88 s for the MLG method, and 163 s for the Lat-Long grid method. We present a discussion of the amount of CPU time required for each of the simulation processes (updating aircraft trajectories, sorting, conflict detection and resolution, etc.), and show that the main advantage of the MLG method is that it is a general sorting algorithm that can sort on multiple properties. We discuss how many MLG neighbors must be considered in the separation assurance procedure in order to ensure a five-mile separation buffer between aircraft, and we investigate the effect of removing waypoints from aircraft trajectories. When aircraft choose their own trajectory, there are more flights with shorter duration times and fewer CD&R maneuvers, resulting in significant fuel savings.

  3. Dealing with the white death: avalanche risk management for traffic routes.

    PubMed

    Rheinberger, Christoph M; Bründl, Michael; Rhyner, Jakob

    2009-01-01

    This article discusses mitigation strategies to protect traffic routes from snow avalanches. Up to now, mitigation of snow avalanches on many roads and railways in the Alps has relied on avalanche sheds, which require large initial investments resulting in high opportunity costs. Therefore, avalanche risk managers have increasingly adopted organizational mitigation measures such as warning systems and closure policies instead. The effectiveness of these measures is, however, greatly dependent on human decisions. In this article, we present a method for optimizing avalanche mitigation for traffic routes in terms of both their risk reduction impact and their net benefit to society. First, we introduce a generic framework for assessing avalanche risk and for quantifying the impact of mitigation. This allows for sound cost-benefit comparisons between alternative mitigation strategies. Second, we illustrate the framework with a case study from Switzerland. Our findings suggest that site-specific characteristics of avalanche paths, as well as the economic importance of a traffic route, are decisive for the choice of optimal mitigation strategies. On routes endangered by few avalanche paths with frequent avalanche occurrences, structural measures are most efficient, whereas reliance on organizational mitigation is often the most appropriate strategy on routes endangered by many paths with infrequent or fuzzy avalanche risk. Finally, keeping a traffic route open may be very important for tourism or the transport industry. Hence, local economic value may promote the use of a hybrid strategy that combines organizational and structural measures to optimize the resource allocation of avalanche risk mitigation.

  4. Longitudinal annoyance responses to a road traffic noise management strategy that reduced heavy vehicles at night.

    PubMed

    Brown, A L

    2015-01-01

    A traffic management strategy was designed to reduce trucks using an urban corridor. The intervention had potential to affect night-time truck flows, but did not target truck traffic in the day, or vehicles other than trucks at any hour. A two-year long panel study measured the community's response to this intervention, using five repeated measurements of response. There were significant reductions in the panel's response to noise, both for night-time annoyance and for interference with activities. This was remarkable given that noise monitoring showed that the intervention produced no change in conventional traffic noise indicators. However, there were measureable changes in the number of articulated truck movements at night, and the benefit can be attributed to reduction in the number of noise events from heavy vehicles. The parallel tracking of changes in reported noise effects and the numbers of heavy vehicles in the night hours in this longitudinal study provides strong support to the notion that noise effects at night depend on the number of noise events experienced, not only on the overall level of traffic noise. The latter appear to be unresponsive indicators by which to assess the noise-effect benefit of heavy vehicle reduction strategies.

  5. Trajectory-Oriented Approach to Managing Traffic Complexity: Trajectory Flexibility Metrics and Algorithms and Preliminary Complexity Impact Assessment

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Vivona, Robert A.; Al-Wakil, Tarek

    2009-01-01

    This document describes exploratory research on a distributed, trajectory oriented approach for traffic complexity management. The approach is to manage traffic complexity based on preserving trajectory flexibility and minimizing constraints. In particular, the document presents metrics for trajectory flexibility; a method for estimating these metrics based on discrete time and degree of freedom assumptions; a planning algorithm using these metrics to preserve flexibility; and preliminary experiments testing the impact of preserving trajectory flexibility on traffic complexity. The document also describes an early demonstration capability of the trajectory flexibility preservation function in the NASA Autonomous Operations Planner (AOP) platform.

  6. A time-based concept for terminal-area traffic management

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Tobias, Leonard

    1986-01-01

    An automated air-traffic-management concept that has the potential for significantly increasing the efficiency of traffic flows in high-density terminal areas is discussed. The concept's implementation depends on techniques for controlling the landing time of all aircraft entering the terminal area, both those that are equipped with on-board four-dimensional (4D) guidance systems as well as those aircraft types that are conventionally equipped. The two major ground-based elements of the system are a scheduler which assigns conflict-free landing times and a profile descent advisor. Landing time provided by the scheduler is uplinked to equipped aircraft and translated into the appropriate 4D trajectory by the-board flight-management system. The controller issues descent advisories to unequipped aircraft to help them achieve the assigned landing times. Air traffic control simulations have established that the concept provides an efficient method for controlling various mixes of 4D-equipped and unequipped, as well as low- and high-performance, aircraft. Piloted simulations of profiles flown with the aid of advisories have verified the ability to meet specified descent times with prescribed accuracy.

  7. A time-based concept for terminal-area traffic management

    NASA Technical Reports Server (NTRS)

    Erzberger, H.; Tobias, L.

    1986-01-01

    An automated air-traffic-management concept that has the potential for significantly increasing the efficiency of traffic flows in high-density terminal areas is discussed. The concept's implementation depends on the techniques for controlling the landing time of all aircraft entering the terminal area, both those that are equipped with on-board four dimensional guidance systems as well as those aircraft types that are conventionally equipped. The two major ground-based elements of the system are a scheduler which assigns conflict-free landing times and a profile descent advisor. Landing times provided by the scheduler are uplinked to equipped aircraft and translated into the appropriate four dimensional trajectory by the on-board flight-management system. The controller issues descent advisories to unequipped aircraft to help them achieve the assigned landing times. Air traffic control simulations have established that the concept provides an efficient method for controlling various mixes of four dimensional-equipped and unequipped, as well as low-and high-performance, aircraft.

  8. Interaction of Airspace Partitions and Traffic Flow Management Delay with Weather

    NASA Technical Reports Server (NTRS)

    Lee, Hak-Tae; Chatterji, Gano B.; Palopo, Kee

    2011-01-01

    The interaction of partitioning the airspace and delaying flights in the presence of convective weather is explored to study how re-partitioning the airspace can help reduce congestion and delay. Three approaches with varying complexities are employed to compute the ground delays.In the first approach, an airspace partition of 335 high-altitude sectors that is based on clear weather day traffic is used. Routes are then created to avoid regions of convective weather. With traffic flow management, this approach establishes the baseline with per-flight delay of 8.4 minutes. In the second approach, traffic flow management is used to select routes and assign departure delays such that only the airport capacity constraints are met. This results in 6.7 minutes of average departure delay. The airspace is then partitioned with a specific capacity. It is shown that airspace-capacity-induced delay can be reduced to zero ata cost of 20percent more sectors for the examined scenario.

  9. Human decision making in future ATC systems comparative studies in distributed traffic management

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.; Wempe, T. E.

    1974-01-01

    Seven different human-centered alternatives for distributing traffic management responsibility between air and ground in the terminal area were simulated and evaluated at NASA-Ames Research Center in the man-machine integration branch. The alternatives differed in three divisions of decision-making responsibility ranging from completely ground-centered to completely air-centered and in the amount of information presented to the pilots via traffic situation displays (TSD). Objective, verbal and subjective measures of system performance, workloads, preferences, etc., were obtained. Based on the task and corresponding measures, the ground-centered (vectoring) alternative was the least favorable. Best overall performance was achieved and preferred with a moderate division of responsibility in which controllers issued sequence order only and pilots used a TSD with 30 sec path predictors on their own aircraft. Speculations on the use of the results in context of a ground-centralized system failure and for future ATC systems are presented.

  10. EDDE, ElectroDynamic Debris Eliminator: New Frontiers in Space Traffic Management

    NASA Astrophysics Data System (ADS)

    Pearson, Jerome; Levin, Eugene; Oldson, John; Carroll, Joseph

    2010-09-01

    The ElectroDynamic Debris Eliminator(EDDE) is a solar-powered propellantless space vehicle that can change its altitude by hundreds of kilometers per day and its orbital plane by degrees per day. It can thrust constantly, producing hundreds of kilometers per second delta-V in years of active maneuvering. A dozen EDDE vehicles could remove all of the 2,500 dangerous debris objects over 2 kg from LEO orbits in less than 7 years and make LEO much safer for the operational spacecraft. To support operations of new kinds of space vehicles like EDDE, space traffic management must be taken to a new level, because these vehicles have to constantly maneuver between the orbits of multiple operational satellites and debris objects, making the space traffic picture very dynamic. Flight tests are planned to demonstrate orbit changes and to evaluate and improve tracking, navigation and control methods.

  11. Unmanned Aircraft Systems Traffic Management (UTM) Safely Enabling UAS Operations in Low-Altitude Airspace

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.

    2016-01-01

    Unmanned Aircraft System (UAS) Traffic Management (UTM) Enabling Civilian Low-Altitude Airspace and Unmanned Aircraft System Operations What is the problem? Many beneficial civilian applications of UAS have been proposed, from goods delivery and infrastructure surveillance, to search and rescue, and agricultural monitoring. Currently, there is no established infrastructure to enable and safely manage the widespread use of low-altitude airspace and UAS operations, regardless of the type of UAS. A UAS traffic management (UTM) system for low-altitude airspace may be needed, perhaps leveraging concepts from the system of roads, lanes, stop signs, rules and lights that govern vehicles on the ground today, whether the vehicles are driven by humans or are automated. What system technologies is NASA exploring? Building on its legacy of work in air traffic management for crewed aircraft, NASA is researching prototype technologies for a UAS Traffic Management (UTM) system that could develop airspace integration requirements for enabling safe, efficient low-altitude operations. While incorporating lessons learned from the today's well-established air traffic management system, which was a response that grew out of a mid-air collision over the Grand Canyon in the early days of commercial aviation, the UTM system would enable safe and efficient low-altitude airspace operations by providing services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning and re-routing, separation management, sequencing and spacing, and contingency management. One of the attributes of the UTM system is that it would not require human operators to monitor every vehicle continuously. The system could provide to human managers the data to make strategic decisions related to initiation, continuation, and termination of airspace operations. This approach would ensure that only authenticated UAS could operate

  12. Trajectory Assessment and Modification Tools for Next Generation Air Traffic Management Operations

    NASA Technical Reports Server (NTRS)

    Brasil, Connie; Lee, Paul; Mainini, Matthew; Lee, Homola; Lee, Hwasoo; Prevot, Thomas; Smith, Nancy

    2011-01-01

    This paper reviews three Next Generation Air Transportation System (NextGen) based high fidelity air traffic control human-in-the-loop (HITL) simulations, with a focus on the expected requirement of enhanced automated trajectory assessment and modification tools to support future air traffic flow management (ATFM) planning positions. The simulations were conducted at the National Aeronautics and Space Administration (NASA) Ames Research Centers Airspace Operations Laboratory (AOL) in 2009 and 2010. The test airspace for all three simulations assumed the mid-term NextGenEn-Route high altitude environment utilizing high altitude sectors from the Kansas City and Memphis Air Route Traffic Control Centers. Trajectory assessment, modification and coordination decision support tools were developed at the AOL in order to perform future ATFM tasks. Overall tool usage results and user acceptability ratings were collected across three areas of NextGen operatoins to evaluate the tools. In addition to the usefulness and usability feedback, feasibility issues, benefits, and future requirements were also addressed. Overall, the tool sets were rated very useful and usable, and many elements of the tools received high scores and were used frequently and successfully. Tool utilization results in all three HITLs showed both user and system benefits including better airspace throughput, reduced controller workload, and highly effective communication protocols in both full Data Comm and mixed-equipage environments.

  13. Semantic Representation and Scale-Up of Integrated Air Traffic Management Data

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.; Ranjan, Shubha; Wei, Mie; Eshow, Michelle

    2016-01-01

    Each day, the global air transportation industry generates a vast amount of heterogeneous data from air carriers, air traffic control providers, and secondary aviation entities handling baggage, ticketing, catering, fuel delivery, and other services. Generally, these data are stored in isolated data systems, separated from each other by significant political, regulatory, economic, and technological divides. These realities aside, integrating aviation data into a single, queryable, big data store could enable insights leading to major efficiency, safety, and cost advantages. In this paper, we describe an implemented system for combining heterogeneous air traffic management data using semantic integration techniques. The system transforms data from its original disparate source formats into a unified semantic representation within an ontology-based triple store. Our initial prototype stores only a small sliver of air traffic data covering one day of operations at a major airport. The paper also describes our analysis of difficulties ahead as we prepare to scale up data storage to accommodate successively larger quantities of data -- eventually covering all US commercial domestic flights over an extended multi-year timeframe. We review several approaches to mitigating scale-up related query performance concerns.

  14. Airborne Four-Dimensional Flight Management in a Time-based Air Traffic Control Environment

    NASA Technical Reports Server (NTRS)

    Williams, David H.; Green, Steven M.

    1991-01-01

    Advanced Air Traffic Control (ATC) systems are being developed which contain time-based (4D) trajectory predictions of aircraft. Airborne flight management systems (FMS) exist or are being developed with similar 4D trajectory generation capabilities. Differences between the ATC generated profiles and those generated by the airborne 4D FMS may introduce system problems. A simulation experiment was conducted to explore integration of a 4D equipped aircraft into a 4D ATC system. The NASA Langley Transport Systems Research Vehicle cockpit simulator was linked in real time to the NASA Ames Descent Advisor ATC simulation for this effort. Candidate procedures for handling 4D equipped aircraft were devised and traffic scenarios established which required time delays absorbed through speed control alone or in combination with path stretching. Dissimilarities in 4D speed strategies between airborne and ATC generated trajectories were tested in these scenarios. The 4D procedures and FMS operation were well received by airline pilot test subjects, who achieved an arrival accuracy at the metering fix of 2.9 seconds standard deviation time error. The amount and nature of the information transmitted during a time clearance were found to be somewhat of a problem using the voice radio communication channel. Dissimilarities between airborne and ATC-generated speed strategies were found to be a problem when the traffic remained on established routes. It was more efficient for 4D equipped aircraft to fly trajectories with similar, though less fuel efficient, speeds which conform to the ATC strategy. Heavy traffic conditions, where time delays forced off-route path stretching, were found to produce a potential operational benefit of the airborne 4D FMS.

  15. A Cognitive-System Model for En Route Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Pisanich, Gregory; Lebacqz, J. Victor (Technical Monitor)

    1998-01-01

    NASA Ames Research Center has been engaged in the development of advanced air traffic management technologies whose basic form is cognitive aiding systems for air traffic controller and flight deck operations. In the design and evaluation of such systems the dynamic interaction between the airborne aiding system and the ground-based aiding systems forms a critical coupling for control. The human operator is an integral control element in the system and the optimal integration of human decision and performance parameters with those of the automation aiding systems offers a significant challenge to cognitive engineering. This paper presents a study in full mission simulation and the development of a predictive computational model of human performance. We have found that this combination of methodologies provide a powerful design-aiding process. We have extended the computational model Man Machine Integrated Design and Analysis System (N13DAS) to include representation of multiple cognitive agents (both human operators and intelligent aiding systems), operating aircraft airline operations centers and air traffic control centers in the evolving airspace. The demands of this application require the representation of many intelligent agents sharing world-models, and coordinating action/intention with cooperative scheduling of goals and actions in a potentially unpredictable world of operations. The operator's activity structures have been developed to include prioritization and interruption of multiple parallel activities among multiple operators, to provide for anticipation (knowledge of the intention and action of remote operators), and to respond to failures of the system and other operators in the system in situation-specific paradigms. We have exercised this model in a multi-air traffic sector scenario with potential conflict among aircraft at and across sector boundaries. We have modeled the control situation as a multiple closed loop system. The inner and outer

  16. Coordinated traffic incident management using the I-Net embedded sensor architecture

    NASA Astrophysics Data System (ADS)

    Dudziak, Martin J.

    1999-01-01

    The I-Net intelligent embedded sensor architecture enables the reconfigurable construction of wide-area remote sensing and data collection networks employing diverse processing and data acquisition modules communicating over thin- server/thin-client protocols. Adaptive initially for operation using mobile remotely-piloted vehicle platforms such as small helicopter robots such as the Hornet and Ascend-I, the I-Net architecture lends itself to a critical problem in the management of both spontaneous and planned traffic congestion and rerouting over major interstate thoroughfares such as the I-95 Corridor. Pre-programmed flight plans and ad hoc operator-assisted navigation of the lightweight helicopter, using an auto-pilot and gyroscopic stabilization augmentation units, allows daytime or nighttime over-the-horizon flights of the unit to collect and transmit real-time video imagery that may be stored or transmitted to other locations. With on-board GPS and ground-based pattern recognition capabilities to augment the standard video collection process, this approach enables traffic management and emergency response teams to plan and assist real-time in the adjustment of traffic flows in high- density or congested areas or during dangerous road conditions such as during ice, snow, and hurricane storms. The I-Net architecture allows for integration of land-based and roadside sensors within a comprehensive automated traffic management system with communications to and form an airborne or other platform to devices in the network other than human-operated desktop computers, thereby allowing more rapid assimilation and response for critical data. Experiments have been conducted using several modified platforms and standard video and still photographic equipment. Current research and development is focused upon modification of the modular instrumentation units in order to accommodate faster loading and reloading of equipment onto the RPV, extension of the I-Net architecture to

  17. Traffic Management Advisor: Iterative Field Development and Assessment at Multiple Sites

    NASA Technical Reports Server (NTRS)

    Sanford, Beverly D.; Lee, Katharine K.; Harwood, Kelly; Denery, Dallas G. (Technical Monitor)

    1995-01-01

    Previous studies have demonstrated the necessity of involving users in the development of automation aids, especially for complex domains such as air traffic control (ATC). Traditional development only demanded a single field test to validate a completed system, but a more iterative combination of development and assessment ensures that the technology meets the requirements of its application domain. Exposure across an adequate spectrum of field users is also required during development, and the use of multiple development sites provides an opportunity to consider individual facility cultures as they relate to implementation strategies. The development of the Center/TRACON Automation System (CTAS) Traffic Management Advisor (TMA) at the Denver and Dallas ATC facilities demonstrates successful iterative development and assessment at multiple field sites. The use of field development changes the nature of assessment. As development progresses, periodic assessments are required to validate that system development is progressing along an appropriate track. In the development of the TMA, assessments were performed based on software in the field, and input from traffic managers was analyzed and incorporated into subsequent releases of the TMA, to be reassessed in the field. This has led to a tool with operational suitability and broad user acceptance. Assessment at multiple sites provides a more generalizable perspective that allows the production of a system that is both generic enough to be used at different sites and tailored enough to be of use at any site. In addition to providing a better understanding of specific facility requirements, the use of multiple assessment sites in the development of TMA has provided an opportunity to consider individual facility operations, procedures and cultures as they relate to development and implementation strategies.

  18. Status of the IAA study group on traffic management rules for space operations

    NASA Astrophysics Data System (ADS)

    Contant, Corinne; Lala, Petr; Schrogl, Kai-Uwe

    2007-10-01

    The investigation of space traffic and its management has only recently become a point of wider discussion. In particular, the series of workshops organized by the American Institute of Aeronautics and Astronautics (AIAA) and other international organizations on international cooperation highlighted the issue. It was discussed thoroughly at the workshops, which took place in 1999 and 2001, respectively. It was at the 2001 workshop, when the suggestion was made that an International Academy of Astronautics (IAA) Study on the subject of space traffic management should be prepared. This suggestion was taken up and a proposal was presented to the Board of Trustees of IAA, which, in late 2001, accepted this proposal. Following this, an interdisciplinary study group of around 20 persons was composed. One early milestone in the process of work was the conduct of an International Institute of Space Law (IISL)/European Center of Space Law (ECSL) Symposium alongside the 2002 session of the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS) Legal Subcommittee. This symposium consisted of presentations of members of the IAA study group. Also, close coordination with other study projects of IAA, in particular with the one on space debris, is sought. This paper presents the status of work of the study group, in particular, the approach and the scope of the study as well as its preliminary findings. The study group intends to finalize its work in early 2004, in order to be able to put the study before IAA and launch its review process before the 2004 International Astronautical Congress. Following this review, the study will be published and may be expected to make an impact in fora like the UNCOPUOS. The authors of this paper act as the coordinators/the rapporteur to this study. The paper will be presented in the IAA—as well as the IISL—session dealing with space traffic, by that bridging the two areas and seeking input from various sources.

  19. 77 FR 3544 - Meeting and Webinar on the Active Traffic and Demand Management and Intelligent Network Flow...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-24

    ... Management and Intelligent Network Flow Optimization Operational Concepts; Notice of Public Meeting AGENCY... Traffic and Demand Management (ADTM) and Intelligent Network Flow Optimization (INFLO) operational concepts. The ADTM meeting is scheduled for February 7, 2012, 8:30 a.m. to 4:30 p.m. followed by the...

  20. Evaluation of Early Ground Control Station Configurations for Interacting with a UAS Traffic Management (UTM) System

    NASA Technical Reports Server (NTRS)

    Dao, Arik-Quang V.; Martin, Lynne; Mohlenbrink, Christoph; Bienert, Nancy; Wolte, Cynthia; Gomez, Ashley; Claudatos, Lauren; Mercer, Joey

    2017-01-01

    The purpose of this paper is to report on a human factors evaluation of ground control station design concepts for interacting with an unmanned traffic management system. The data collected for this paper comes from recent field tests for NASA's Unmanned Traffic Management (UTM) project, and covers the following topics; workload, situation awareness, as well as flight crew communication, coordination, and procedures. The goal of this evaluation was to determine if the various software implementations for interacting with the UTM system can be described and classified into design concepts to provide guidance for the development of future UTM interfaces. We begin with a brief description of NASA's UTM project, followed by a description of the test range configuration related to a second development phase. We identified (post hoc) two classes in which the ground control stations could be grouped. This grouping was based on level of display integration. The analysis was exploratory and informal. It was conducted to compare ground stations across those two classes and against the aforementioned topics. Herein, we discuss the results.

  1. Profile negotiation - A concept for integrating airborne and ground-based automation for managing arrival traffic

    NASA Technical Reports Server (NTRS)

    Green, Steven M.; Den Braven, Wim; Williams, David H.

    1991-01-01

    The profile negotiation process (PNP) concept as applied to the management of arrival traffic within the extended terminal area is presented, focusing on functional issues from the ground-based perspective. The PNP is an interactive process between an aircraft and air traffic control (ATC) which combines airborne and ground-based automation capabilities to determine conflict-free trajectories that are as close to an aircraft's preference as possible. Preliminary results from a real-time simulation study show that the controller teams are able to consistently and effectively negotiate conflict-free vertical profiles with 4D-equipped aircraft. The ability of the airborne 4D flight management system to adapt to ATC specified 4D trajectory constraints is found to be a requirement for successful execution of the PNP. It is recommended that the conventional method of cost index iteration for obtaining the minimum fuel 4D trajectory be supplemented by a method which constrains the profile speeds to those desired by ATC.

  2. Human-System Safety Methods for Development of Advanced Air Traffic Management Systems

    SciTech Connect

    Nelson, W.R.

    1999-05-24

    The Idaho National Engineering and Environmental Laboratory (INEEL) is supporting the National Aeronautics and Space Administration in the development of advanced air traffic management (ATM) systems as part of the Advanced Air Transportation Technologies program. As part of this program INEEL conducted a survey of human-system safety methods that have been applied to complex technical systems, to identify lessons learned from these applications and provide recommendations for the development of advanced ATM systems. The domains that were surveyed included offshore oil and gas, commercial nuclear power, commercial aviation, and military. The survey showed that widely different approaches are used in these industries, and that the methods used range from very high-level, qualitative approaches to very detailed quantitative methods such as human reliability analysis (HRA) and probabilistic safety assessment (PSA). In addition, the industries varied widely in how effectively they incorporate human-system safety assessment in the design, development, and testing of complex technical systems. In spite of the lack of uniformity in the approaches and methods used, it was found that methods are available that can be combined and adapted to support the development of advanced air traffic management systems.

  3. Unmanned Aerial System (UAS) Traffic Management (UTM): Enabling Low-Altitude Airspace and UAS Operations

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.

    2014-01-01

    Many civilian applications of Unmanned Aerial Systems (UAS) have been imagined ranging from remote to congested urban areas, including goods delivery, infrastructure surveillance, agricultural support, and medical services delivery. Further, these UAS will have different equipage and capabilities based on considerations such as affordability, and mission needs applications. Such heterogeneous UAS mix, along with operations such as general aviation, helicopters, gliders must be safely accommodated at lower altitudes. However, key infrastructure to enable and safely manage widespread use of low-altitude airspace and UAS operations therein does not exist. Therefore, NASA is exploring functional design, concept and technology development, and a prototype UAS Traffic Management (UTM) system. UTM will support safe and efficient UAS operations for the delivery of goods and services

  4. Research Traffic Management Advisor (rTMA) Up-level Final Report

    NASA Technical Reports Server (NTRS)

    Capps, Richard A.

    2013-01-01

    The FAA Time Based Flow Management (TBFM) Program provides for operational use and continued development of the Traffic Management Advisor (TMA) technology that NASA demonstrated in 1996. Although NASA's Center-TRACON Automation System (CTAS) software baseline includes advanced versions of TMA, some research activities are better served by a version of TMA that more closely matches the FAA's TBFM software. Beginning in 2009, NASA created Research TMA (rTMA) to enable researchers to work with FAA TBFM software in a research environment. The original rTMA was derived from TBFM v3.10 and later up-leveled to TBFM v3.12. This report documents the most recent up-level effort in which rTMA was re-derived from TBFM v4.00.07.

  5. Modeling Air Traffic Management Technologies with a Queuing Network Model of the National Airspace System

    NASA Technical Reports Server (NTRS)

    Long, Dou; Lee, David; Johnson, Jesse; Gaier, Eric; Kostiuk, Peter

    1999-01-01

    This report describes an integrated model of air traffic management (ATM) tools under development in two National Aeronautics and Space Administration (NASA) programs -Terminal Area Productivity (TAP) and Advanced Air Transport Technologies (AATT). The model is made by adjusting parameters of LMINET, a queuing network model of the National Airspace System (NAS), which the Logistics Management Institute (LMI) developed for NASA. Operating LMINET with models of various combinations of TAP and AATT will give quantitative information about the effects of the tools on operations of the NAS. The costs of delays under different scenarios are calculated. An extension of Air Carrier Investment Model (ACIM) under ASAC developed by the Institute for NASA maps the technologies' impacts on NASA operations into cross-comparable benefits estimates for technologies and sets of technologies.

  6. Air Ground Integration and the Brigade Combat Team

    DTIC Science & Technology

    2013-06-13

    source of information on the ADAM Cell comes from FMI 3-01.50, Air Defense and Airspace Management Cell Operations. This publication outlines the...BCT. CPT Engelbrecht outlines issues with doctrine, organization, and training in preparing the ADAM Cell for operations. FMI 3-01.50 is full of...responsibilities of each cell within the BCT are clearly outlined by doctrine. Field Manual Interim ( FMI ) 3-01.50, Air Defense and Airspace Management Cell

  7. Pilot in Command: An Illustration of Autonomous Flight Management

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Ponthieux, Joseph G.

    2004-01-01

    Several years of NASA research have produced the concept for air traffic management called "Distributed Air/Ground Traffic Management," a major operational advancement that should significantly increase the capacity of the National Airspace System. A key component, "Autonomous Flight Management," introduces a new class of aircraft operations in which pilots are authorized to freely maneuver and execute optimal trajectories independent from air traffic controllers. These aircraft operators would benefit from significant increases in flexibility to optimize all flight operations and from avoiding most of the delays associated with ground-controlled operations. Responsibilities for aircraft separation and arrival flow conformance are transferred to the flight deck, and the pilots use computerized decision-support tools to accomplish these tasks. A research prototype of these tools called the "Autonomous Operations Planner" is being developed at the NASA Langley Research Center. This 14-minute video illustrates Autonomous Flight Management from the airline pilot's perspective.

  8. Formal Methods in Air Traffic Management: The Case of Unmanned Aircraft Systems

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.

    2015-01-01

    As the technological and operational capabilities of unmanned aircraft systems (UAS) continue to grow, so too does the need to introduce these systems into civil airspace. Unmanned Aircraft Systems Integration in the National Airspace System is a NASA research project that addresses the integration of civil UAS into non-segregated airspace operations. One of the major challenges of this integration is the lack of an onboard pilot to comply with the legal requirement that pilots see and avoid other aircraft. The need to provide an equivalent to this requirement for UAS has motivated the development of a detect and avoid (DAA) capability to provide the appropriate situational awareness and maneuver guidance in avoiding and remaining well clear of traffic aircraft. Formal methods has played a fundamental role in the development of this capability. This talk reports on the formal methods work conducted under NASA's Safe Autonomous System Operations project in support of the development of DAA for UAS. This work includes specification of low-level and high-level functional requirements, formal verification of algorithms, and rigorous validation of software implementations. The talk also discusses technical challenges in formal methods research in the context of the development and safety analysis of advanced air traffic management concepts.

  9. Aeronautical Communications Research and Development Needs for Future Air Traffic Management Applications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.

    2002-01-01

    Continuing growth in regional and global air travel has resulted in increasing traffic congestion in the air and on the ground. In spite of occasional temporary downturns due to economic recessions and catastrophic events, average growth rates of air travel have remained high since the 1960s. The resulting congestion, which constrains expansion of the air transportation industry, inflicts schedule delays and decreases overall system efficiency, creating a pressing need to develop more efficient methods of air traffic management (ATM). New ATM techniques, procedures, air space automation methods, and decision support tools are being researched and developed for deployment in time frames stretching from the next few years to the year 2020 and beyond. As these methods become more advanced and increase in complexity, the requirements for information generation, sharing and transfer among the relevant entities in the ATM system increase dramatically. However, current aeronautical communications systems will be inadequate to meet the future information transfer demands created by these advanced ATM systems. Therefore, the NASA Glenn Research Center is undertaking research programs to develop communication, methods and key technologies that can meet these future requirements. As part of this process, studies, workshops, testing and experimentation, and research and analysis have established a number of research and technology development needs. The purpose of this paper is to outline the critical research and technology needs that have been identified in these activities, and explain how these needs have been determined.

  10. A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management

    PubMed Central

    Li, Tianxin; Meng, Linglong; Herman, Uwizeyimana; Lu, Zhongming; Crittenden, John

    2015-01-01

    Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease) along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = −0.8267, p = 0.0017) and CAT (r = −0.89, p = 0.0002) activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants. PMID:26457711

  11. A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management.

    PubMed

    Li, Tianxin; Meng, Linglong; Herman, Uwizeyimana; Lu, Zhongming; Crittenden, John

    2015-10-08

    Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease) along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = -0.8267, p = 0.0017) and CAT (r = -0.89, p = 0.0002) activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants.

  12. Simulation evaluation of TIMER, a time-based, terminal air traffic, flow-management concept

    NASA Technical Reports Server (NTRS)

    Credeur, Leonard; Capron, William R.

    1989-01-01

    A description of a time-based, extended terminal area ATC concept called Traffic Intelligence for the Management of Efficient Runway scheduling (TIMER) and the results of a fast-time evaluation are presented. The TIMER concept is intended to bridge the gap between today's ATC system and a future automated time-based ATC system. The TIMER concept integrates en route metering, fuel-efficient cruise and profile descents, terminal time-based sequencing and spacing together with computer-generated controller aids, to improve delivery precision for fuller use of runway capacity. Simulation results identify and show the effects and interactions of such key variables as horizon of control location, delivery time error at both the metering fix and runway threshold, aircraft separation requirements, delay discounting, wind, aircraft heading and speed errors, and knowledge of final approach speed.

  13. Development of a Prototype Automation Simulation Scenario Generator for Air Traffic Management Software Simulations

    NASA Technical Reports Server (NTRS)

    Khambatta, Cyrus F.

    2007-01-01

    A technique for automated development of scenarios for use in the Multi-Center Traffic Management Advisor (McTMA) software simulations is described. The resulting software is designed and implemented to automate the generation of simulation scenarios with the intent of reducing the time it currently takes using an observational approach. The software program is effective in achieving this goal. The scenarios created for use in the McTMA simulations are based on data taken from data files from the McTMA system, and were manually edited before incorporation into the simulations to ensure accuracy. Despite the software s overall favorable performance, several key software issues are identified. Proposed solutions to these issues are discussed. Future enhancements to the scenario generator software may address the limitations identified in this paper.

  14. Convergence of Vehicle and Infrastructure Data for Traffic and Demand Management

    SciTech Connect

    Young, Stanley E.

    2015-11-16

    measurement of the quality of progression along a corridor. Though still requiring an investment in equipment and communications, these data sources are transforming traffic signal management to a data driven, performance management basis. Ever increasing availability of granular GPS trace data from automobiles may allow for assessment of traffic signal performance, allowing for signal optimization while minimizing the investment in additional sensors and communication infrastructure.

  15. A Harmonized Perspective on Transportation Management in Smart Cities: The Novel IoT-Driven Environment for Road Traffic Modeling.

    PubMed

    Masek, Pavel; Masek, Jan; Frantik, Petr; Fujdiak, Radek; Ometov, Aleksandr; Hosek, Jiri; Andreev, Sergey; Mlynek, Petr; Misurec, Jiri

    2016-11-08

    The unprecedented growth of today's cities together with increased population mobility are fueling the avalanche in the numbers of vehicles on the roads. This development led to the new challenges for the traffic management, including the mitigation of road congestion, accidents, and air pollution. Over the last decade, researchers have been focusing their efforts on leveraging the recent advances in sensing, communications, and dynamic adaptive technologies to prepare the deployed road traffic management systems (TMS) for resolving these important challenges in future smart cities. However, the existing solutions may still be insufficient to construct a reliable and secure TMS that is capable of handling the anticipated influx of the population and vehicles in urban areas. Along these lines, this work systematically outlines a perspective on a novel modular environment for traffic modeling, which allows to recreate the examined road networks in their full resemblance. Our developed solution is targeted to incorporate the progress in the Internet of Things (IoT) technologies, where low-power, embedded devices integrate as part of a next-generation TMS. To mimic the real traffic conditions, we recreated and evaluated a practical traffic scenario built after a complex road intersection within a large European city.

  16. A Harmonized Perspective on Transportation Management in Smart Cities: The Novel IoT-Driven Environment for Road Traffic Modeling

    PubMed Central

    Masek, Pavel; Masek, Jan; Frantik, Petr; Fujdiak, Radek; Ometov, Aleksandr; Hosek, Jiri; Andreev, Sergey; Mlynek, Petr; Misurec, Jiri

    2016-01-01

    The unprecedented growth of today’s cities together with increased population mobility are fueling the avalanche in the numbers of vehicles on the roads. This development led to the new challenges for the traffic management, including the mitigation of road congestion, accidents, and air pollution. Over the last decade, researchers have been focusing their efforts on leveraging the recent advances in sensing, communications, and dynamic adaptive technologies to prepare the deployed road traffic management systems (TMS) for resolving these important challenges in future smart cities. However, the existing solutions may still be insufficient to construct a reliable and secure TMS that is capable of handling the anticipated influx of the population and vehicles in urban areas. Along these lines, this work systematically outlines a perspective on a novel modular environment for traffic modeling, which allows to recreate the examined road networks in their full resemblance. Our developed solution is targeted to incorporate the progress in the Internet of Things (IoT) technologies, where low-power, embedded devices integrate as part of a next-generation TMS. To mimic the real traffic conditions, we recreated and evaluated a practical traffic scenario built after a complex road intersection within a large European city. PMID:27834796

  17. Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps), Version 3.0

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Johnson, William C.; Scardina, John; Shay, Richard F.

    2016-01-01

    This document describes the goals, benefits, technologies, and procedures of the Concept of Operations (ConOps) for the Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1), and provides an update to the previous versions of the document [ref 1 and ref 2].

  18. DOD Pilot Program for Shipment of Personal Property - Military Traffic Management Command Reengineering DOD Personal Property Program Pilot

    DTIC Science & Technology

    2007-11-02

    that the Military Traffic Management Command ( MTMC ) manages for the Services, DoD agencies, and the U.S. Coast Guard. MTMC is the single largest...Command ( MTMC ) to determine the baseline costs for the existing DoD Personal Property Program (the Baseline Program); the methodology and processes...used to collect, evaluate, and report transportation and cost data for the MTMC Reengineering DoD Personal Property Program Pilot (the MTMC Program

  19. Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Wing, David; Prevot, Thomas; Morey, Susan; Lewis, Timothy; Martin, Lynne; Johnson, Sally; Cabrall, Christopher; Como, Sean; Homola, Jeffrey; Sheth-Chandra, Manasi; Mercer, Joey

    2013-01-01

    Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by ground-based automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations, assuming the starting point of current-day operations and modeling an emergence of NextGen technologies and procedures. In the controller-focused experiment, the impact of mixed operations on controller performance was assessed at four stages of NextGen implementation. In the pilot-focused experiment, the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft were tested. Results indicate that the presence of self-separating aircraft had little impact on the controllers' ability to provide separation services for ground-controlled aircraft. Overall performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent information for all aircraft. In this environment, safe, efficient, and highly acceptable operations could be achieved for twice today's peak airspace throughput. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited the safely achievable airspace throughput and

  20. A Critical Survey of Optimization Models for Tactical and Strategic Aspects of Air Traffic Flow Management

    NASA Technical Reports Server (NTRS)

    Bertsimas, Dimitris; Odoni, Amedeo

    1997-01-01

    This document presents a critical review of the principal existing optimization models that have been applied to Air Traffic Flow Management (TFM). Emphasis will be placed on two problems, the Generalized Tactical Flow Management Problem (GTFMP) and the Ground Holding Problem (GHP), as well as on some of their variations. To perform this task, we have carried out an extensive literature review that has covered more than 40 references, most of them very recent. Based on the review of this emerging field our objectives were to: (i) identify the best available models; (ii) describe typical contexts for applications of the models; (iii) provide illustrative model formulations; and (iv) identify the methodologies that can be used to solve the models. We shall begin our presentation below by providing a brief context for the models that we are reviewing. In Section 3 we shall offer a taxonomy and identify four classes of models for review. In Sections 4, 5, and 6 we shall then review, respectively, models for the Single-Airport Ground Holding Problem, the Generalized Tactical FM P and the Multi-Airport Ground Holding Problem (for the definition of these problems see Section 3 below). In each section, we identify the best available models and discuss briefly their computational performance and applications, if any, to date. Section 7 summarizes our conclusions about the state of the art.

  1. Crash Injury Management: Emergency Medical Services for Traffic Law Enforcement Officers. Student Study Guide.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    To assist in the continuing efforts to improve the safety of the motorist on the nation's highways and roads, this student guide provides a standardized approach for first responders to traffic accidents to learn emergency medical care. Training is provided in all aspects of emergency medical care required at the scene of a traffic accident.…

  2. Analysis of Traffic Conflicts in a Mixed-Airspace Evaluation of Airborne Separation Assurance

    NASA Technical Reports Server (NTRS)

    Lewis, Timothy A.

    2013-01-01

    A pair of human-in-the-loop simulation evaluations of a distributed air/ground separation assurance system have been conducted to investigate the function allocation between humans and automation systems as well as ground-based and airborne agents in the Next Generation Air Transportation System and beyond. This paper focuses on an analysis of certain critical conflicts observed between self-separating aircraft and ground-managed traffic in the same airspace. The principal cause of each conflict is identified and potential mitigations are discussed, such as: the sharing of trajectory intent information between the ground and the air; more cautious trajectory planning by the self-separating aircraft; and more equitable rules-of-the-road between the self-separating aircraft and ground-managed aircraft. This analysis will inform the ongoing design of an airborne separation assurance automation tool.

  3. Analysis of Multi-Flight Common Routes for Traffic Flow Management

    NASA Technical Reports Server (NTRS)

    Sheth, Kapil; Clymer, Alexis; Morando, Alex; Shih, Fu-Tai

    2016-01-01

    This paper presents an approach for creating common weather avoidance reroutes for multiple flights and the associated benefits analysis, which is an extension of the single flight advisories generated using the Dynamic Weather Routes (DWR) concept. These multiple flight advisories are implemented in the National Airspace System (NAS) Constraint Evaluation and Notification Tool (NASCENT), a nation-wide simulation environment to generate time- and fuel-saving alternate routes for flights during severe weather events. These single flight advisories are clustered together in the same Center by considering parameters such as a common return capture fix. The clustering helps propose routes called, Multi-Flight Common Routes (MFCR), that avoid weather and other airspace constraints, and save time and fuel. It is expected that these routes would also provide lower workload for traffic managers and controllers since a common route is found for several flights, and presumably the route clearances would be easier and faster. This study was based on 30-days in 2014 and 2015 each, which had most delays attributed to convective weather. The results indicate that many opportunities exist where individual flight routes can be clustered to fly along a common route to save a significant amount of time and fuel, and potentially reducing the amount of coordination needed.

  4. Impact of Conflict Avoidance Responsibility Allocation on Pilot Workload in a Distributed Air Traffic Management System

    NASA Technical Reports Server (NTRS)

    Ligda, Sarah V.; Dao, Arik-Quang V.; Vu, Kim-Phuong; Strybel, Thomas Z.; Battiste, Vernol; Johnson, Walter W.

    2010-01-01

    Pilot workload was examined during simulated flights requiring flight deck-based merging and spacing while avoiding weather. Pilots used flight deck tools to avoid convective weather and space behind a lead aircraft during an arrival into Louisville International airport. Three conflict avoidance management concepts were studied: pilot, controller or automation primarily responsible. A modified Air Traffic Workload Input Technique (ATWIT) metric showed highest workload during the approach phase of flight and lowest during the en-route phase of flight (before deviating for weather). In general, the modified ATWIT was shown to be a valid and reliable workload measure, providing more detailed information than post-run subjective workload metrics. The trend across multiple workload metrics revealed lowest workload when pilots had both conflict alerting and responsibility of the three concepts, while all objective and subjective measures showed highest workload when pilots had no conflict alerting or responsibility. This suggests that pilot workload was not tied primarily to responsibility for resolving conflicts, but to gaining and/or maintaining situation awareness when conflict alerting is unavailable.

  5. Applying Required Navigation Performance Concept for Traffic Management of Small Unmanned Aircraft Systems

    NASA Technical Reports Server (NTRS)

    Jung, Jaewoo; D'Souza, Sarah N.; Johnson, Marcus A.; Ishihara, Abraham K.; Modi, Hemil C.; Nikaido, Ben; Hasseeb, Hashmatullah

    2016-01-01

    In anticipation of a rapid increase in the number of civil Unmanned Aircraft System(UAS) operations, NASA is researching prototype technologies for a UAS Traffic Management (UTM) system that will investigate airspace integration requirements for enabling safe, efficient low-altitude operations. One aspect a UTM system must consider is the correlation between UAS operations (such as vehicles, operation areas and durations), UAS performance requirements, and the risk to people and property in the operational area. This paper investigates the potential application of the International Civil Aviation Organizations (ICAO) Required Navigation Performance (RNP) concept to relate operational risk with trajectory conformance requirements. The approach is to first define a method to quantify operational risk and then define the RNP level requirement as a function of the operational risk. Greater operational risk corresponds to more accurate RNP level, or smaller tolerable Total System Error (TSE). Data from 19 small UAS flights are used to develop and validate a formula that defines this relationship. An approach to assessing UAS-RNP conformance capability using vehicle modeling and wind field simulation is developed to investigate how this formula may be applied in a future UTM system. The results indicate the modeled vehicles flight path is robust to the simulated wind variation, and it can meet RNP level requirements calculated by the formula. The results also indicate how vehicle-modeling fidelity may be improved to adequately verify assessed RNP level.

  6. Cost estimates for near-term depolyment of advanced traffic management systems. Final report

    SciTech Connect

    Stevens, S.S.; Chin, S.M.

    1993-02-15

    The objective of this study is to provide cost est engineering, design, installation, operation and maintenance of Advanced Traffic Management Systems (ATMS) in the largest 75 metropolitan areas in the United States. This report gives estimates for deployment costs for ATMS in the next five years, subject to the qualifications and caveats set out in following paragraphs. The report considers infrastructure components required to realize fully a functional ATMS over each of two highway networks (as discussed in the Section describing our general assumptions) under each of the four architectures identified in the MITRE Intelligent Vehicle Highway Systems (IVHS) Architecture studies. The architectures are summarized in this report in Table 2. Estimates are given for eight combinations of highway networks and architectures. We estimate that it will cost between $8.5 Billion (minimal network) and $26 Billion (augmented network) to proceed immediately with deployment of ATMS in the largest 75 metropolitan areas. Costs are given in 1992 dollars, and are not adjusted for future inflation. Our estimates are based partially on completed project costs, which have been adjusted to 1992 dollars. We assume that a particular architecture will be chosen; projected costs are broken by architecture.

  7. Communications System Architecture Development for Air Traffic Management and Aviation Weather Information Dissemination

    NASA Technical Reports Server (NTRS)

    Gallagher, Seana; Olson, Matt; Blythe, Doug; Heletz, Jacob; Hamilton, Griff; Kolb, Bill; Homans, Al; Zemrowski, Ken; Decker, Steve; Tegge, Cindy

    2000-01-01

    This document is the NASA AATT Task Order 24 Final Report. NASA Research Task Order 24 calls for the development of eleven distinct task reports. Each task was a necessary exercise in the development of comprehensive communications systems architecture (CSA) for air traffic management and aviation weather information dissemination for 2015, the definition of the interim architecture for 2007, and the transition plan to achieve the desired End State. The eleven tasks are summarized along with the associated Task Order reference. The output of each task was an individual task report. The task reports that make up the main body of this document include Task 5, Task 6, Task 7, Task 8, Task 10, and Task 11. The other tasks provide the supporting detail used in the development of the architecture. These reports are included in the appendices. The detailed user needs, functional communications requirements and engineering requirements associated with Tasks 1, 2, and 3 have been put into a relational database and are provided electronically.

  8. Management-Related Traffic as a Stressor Eliciting Parental Care in a Roadside-Nesting Bird: The European Bee-Eater Merops apiaster.

    PubMed

    Blas, Julio; Abaurrea, Teresa; D'Amico, Marcello; Barcellona, Francesca; Revilla, Eloy; Román, Jacinto; Carrete, Martina

    2016-01-01

    Traffic is often acknowledged as a threat to biodiversity, but its effects have been mostly studied on roads subjected to high traffic intensity. The impact of lower traffic intensity such as those affecting protected areas is generally neglected, but conservation-oriented activities entailing motorized traffic could paradoxically transform suitable habitats into ecological traps. Here we questioned whether roadside-nesting bee-eaters Merops apiaster perceived low traffic intensity as a stressor eliciting risk-avoidance behaviors (alarm calls and flock flushes) and reducing parental care. Comparisons were established within Doñana National Park (Spain), between birds exposed to either negligible traffic (ca. 0-10 vehicles per day) or low traffic intensity (ca. 10-90 vehicles per day) associated to management and research activities. The frequencies of alarm calls and flock flushes were greater in areas of higher traffic intensity, which resulted in direct mortality at moderate vehicle speeds (≤ 40 km/h). Parental feeding rates paralleled changes in traffic intensity, but contrary to our predictions. Indeed, feeding rates were highest in traffic-exposed nests, during working days and traffic rush-hours. Traffic-avoidance responses were systematic and likely involved costs (energy expenditure and mortality), but vehicle transit positively influenced the reproductive performance of bee-eaters through an increase of nestling feeding rates. Because the expected outcome of traffic on individual performance can be opposed when responses are monitored during mating (i.e. negative effect by increase of alarm calls and flock flushes) or nestling-feeding period (i.e. at least short-term positive effect by increase of nestling feeding rates), caution should be taken before inferring fitness consequences only from isolated behaviors or specific life history stages.

  9. Management-Related Traffic as a Stressor Eliciting Parental Care in a Roadside-Nesting Bird: The European Bee-Eater Merops apiaster

    PubMed Central

    Blas, Julio; Abaurrea, Teresa; D’Amico, Marcello; Barcellona, Francesca; Revilla, Eloy; Román, Jacinto; Carrete, Martina

    2016-01-01

    Traffic is often acknowledged as a threat to biodiversity, but its effects have been mostly studied on roads subjected to high traffic intensity. The impact of lower traffic intensity such as those affecting protected areas is generally neglected, but conservation-oriented activities entailing motorized traffic could paradoxically transform suitable habitats into ecological traps. Here we questioned whether roadside-nesting bee-eaters Merops apiaster perceived low traffic intensity as a stressor eliciting risk-avoidance behaviors (alarm calls and flock flushes) and reducing parental care. Comparisons were established within Doñana National Park (Spain), between birds exposed to either negligible traffic (ca. 0–10 vehicles per day) or low traffic intensity (ca. 10–90 vehicles per day) associated to management and research activities. The frequencies of alarm calls and flock flushes were greater in areas of higher traffic intensity, which resulted in direct mortality at moderate vehicle speeds (≤ 40 km/h). Parental feeding rates paralleled changes in traffic intensity, but contrary to our predictions. Indeed, feeding rates were highest in traffic-exposed nests, during working days and traffic rush-hours. Traffic-avoidance responses were systematic and likely involved costs (energy expenditure and mortality), but vehicle transit positively influenced the reproductive performance of bee-eaters through an increase of nestling feeding rates. Because the expected outcome of traffic on individual performance can be opposed when responses are monitored during mating (i.e. negative effect by increase of alarm calls and flock flushes) or nestling-feeding period (i.e. at least short-term positive effect by increase of nestling feeding rates), caution should be taken before inferring fitness consequences only from isolated behaviors or specific life history stages. PMID:27706229

  10. Anomalous Transmission of Infrasound Through Air-Water and Air-Ground Interfaces

    NASA Astrophysics Data System (ADS)

    Godin, O. A.

    2009-05-01

    Speed of compressional waves in air is smaller than in water and in the ground, while mass density of air is much smaller than mass densities of water and the ground. This results in a very strong acoustic impedance contrast at air-water and air-ground interfaces. Sound transmission through a boundary with a strong impedance contrast is normally very weak. This paper reports theoretical studies of the power output of localized sound sources and acoustic power fluxes through plane gas-liquid and gas-solid interfaces in a layered medium. It is found that the transparency of the interfaces increases dramatically at low frequencies. For low-frequency sound, a phenomenon of anomalous transparency can occur where most of the acoustic power generated by a source in water is radiated into the atmosphere. Contrary to the conventional wisdom based on ray-theoretical predictions and observations at higher frequencies, infrasonic energy from localized waterborne sources can be effectively transmitted into air. The main physical mechanism responsible for the anomalous transparency of air-water interface is found to be an acoustic power transfer by inhomogeneous (evanescent) waves in the plane-wave decomposition of the acoustic field in water. The effects of ocean and atmosphere stratification and of guided sound propagation in water or in air on the anomalous transparency of the air-water interface are considered. In the case of air-ground interface, the increase of the acoustic power flux into atmosphere, when a compact source approaches the interface from below, proves to be even larger than for an underwater source. The physics behind the increase of the power flux into the atmosphere, when the source depth decreases, is shown to be rather different for the air-ground and air-water interfaces. Depending on attenuation of compressional and shear waves in the ground, a leaky interface wave supported by the air-ground interface can be responsible for the bulk of acoustic power

  11. Validating an Air Traffic Management Concept of Operation Using Statistical Modeling

    NASA Technical Reports Server (NTRS)

    He, Yuning; Davies, Misty Dawn

    2013-01-01

    Validating a concept of operation for a complex, safety-critical system (like the National Airspace System) is challenging because of the high dimensionality of the controllable parameters and the infinite number of states of the system. In this paper, we use statistical modeling techniques to explore the behavior of a conflict detection and resolution algorithm designed for the terminal airspace. These techniques predict the robustness of the system simulation to both nominal and off-nominal behaviors within the overall airspace. They also can be used to evaluate the output of the simulation against recorded airspace data. Additionally, the techniques carry with them a mathematical value of the worth of each prediction-a statistical uncertainty for any robustness estimate. Uncertainty Quantification (UQ) is the process of quantitative characterization and ultimately a reduction of uncertainties in complex systems. UQ is important for understanding the influence of uncertainties on the behavior of a system and therefore is valuable for design, analysis, and verification and validation. In this paper, we apply advanced statistical modeling methodologies and techniques on an advanced air traffic management system, namely the Terminal Tactical Separation Assured Flight Environment (T-TSAFE). We show initial results for a parameter analysis and safety boundary (envelope) detection in the high-dimensional parameter space. For our boundary analysis, we developed a new sequential approach based upon the design of computer experiments, allowing us to incorporate knowledge from domain experts into our modeling and to determine the most likely boundary shapes and its parameters. We carried out the analysis on system parameters and describe an initial approach that will allow us to include time-series inputs, such as the radar track data, into the analysis

  12. Super Ensemble-based Aviation Turbulence Guidance (SEATG) for Air Traffic Management (ATM)

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Hoon; Chan, William; Sridhar, Banavar; Sharman, Robert

    2014-05-01

    Super Ensemble (ensemble of ten turbulence metrics from time-lagged ensemble members of weather forecast data)-based Aviation Turbulence Guidance (SEATG) is developed using Weather Research and Forecasting (WRF) model and in-situ eddy dissipation rate (EDR) observations equipped on commercial aircraft over the contiguous United States. SEATG is a sequence of five procedures including weather modeling, calculating turbulence metrics, mapping EDR-scale, evaluating metrics, and producing final SEATG forecast. This uses similar methodology to the operational Graphic Turbulence Guidance (GTG) with three major improvements. First, SEATG use a higher resolution (3-km) WRF model to capture cloud-resolving scale phenomena. Second, SEATG computes turbulence metrics for multiple forecasts that are combined at the same valid time resulting in an time-lagged ensemble of multiple turbulence metrics. Third, SEATG provides both deterministic and probabilistic turbulence forecasts to take into account weather uncertainties and user demands. It is found that the SEATG forecasts match well with observed radar reflectivity along a surface front as well as convectively induced turbulence outside the clouds on 7-8 Sep 2012. And, overall performance skill of deterministic SEATG against the observed EDR data during this period is superior to any single turbulence metrics. Finally, probabilistic SEATG is used as an example application of turbulence forecast for air-traffic management. In this study, a simple Wind-Optimal Route (WOR) passing through the potential areas of probabilistic SEATG and Lateral Turbulence Avoidance Route (LTAR) taking into account the SEATG are calculated at z = 35000 ft (z = 12 km) from Los Angeles to John F. Kennedy international airports. As a result, WOR takes total of 239 minutes with 16 minutes of SEATG areas for 40% of moderate turbulence potential, while LTAR takes total of 252 minutes travel time that 5% of fuel would be additionally consumed to entirely

  13. Air traffic management system design using satellite based geo-positioning and communications assets

    NASA Technical Reports Server (NTRS)

    Horkin, Phil

    1995-01-01

    The current FAA and ICAO FANS vision of Air Traffic Management will transition the functions of Communications, Navigation, and Surveillance to satellite based assets in the 21st century. Fundamental to widespread acceptance of this vision is a geo-positioning system that can provide worldwide access with best case differential GPS performance, but without the associated problems. A robust communications capability linking-up aircraft and towers to meet the voice and data requirements is also essential. The current GPS constellation does not provide continuous global coverage with a sufficient number of satellites to meet the precision landing requirements as set by the world community. Periodic loss of the minimum number of satellites in view creates an integrity problem, which prevents GPS from becoming the primary system for navigation. Furthermore, there is reluctance on the part of many countries to depend on assets like GPS and GLONASS which are controlled by military communities. This paper addresses these concerns and provides a system solving the key issues associated with navigation, automatic dependent surveillance, and flexible communications. It contains an independent GPS-like navigation system with 27 satellites providing global coverage with a minimum of six in view at all times. Robust communications is provided by a network of TDMA/FDMA communications payloads contained on these satellites. This network can support simultaneous communications for up to 30,000 links, nearly enough to simultaneously support three times the current global fleet of jumbo air passenger aircraft. All of the required hardware is directly traceable to existing designs.

  14. The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight/The Marine Air-Ground Team: Still Not Adequately Trained for the Urban Fight

    DTIC Science & Technology

    2006-02-01

    1 The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight Subject Area Training EWS 2006...The Marine Air-Ground Team: Still Not Adequately Training for the Urban Fight Submitted by Captain RC Rybka to Majors GC Schreffler and RR...estimated to average 1 hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the

  15. Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps), Version 2.0

    NASA Technical Reports Server (NTRS)

    Baxley, Brian T.; Johnson, William C.; Swenson, Harry N.; Robinson, John E.; Prevot, Tom; Callantine, Todd J.; Scardina, John; Greene, Michael

    2013-01-01

    This document is an update to the operations and procedures envisioned for NASA s Air Traffic Management (ATM) Technology Demonstration #1 (ATD-1). The ATD-1 Concept of Operations (ConOps) integrates three NASA technologies to achieve high throughput, fuel-efficient arrival operations into busy terminal airspace. They are Traffic Management Advisor with Terminal Metering (TMA-TM) for precise time-based schedules to the runway and points within the terminal area, Controller-Managed Spacing (CMS) decision support tools for terminal controllers to better manage aircraft delay using speed control, and Flight deck Interval Management (FIM) avionics and flight crew procedures to conduct airborne spacing operations. The ATD-1 concept provides de-conflicted and efficient operations of multiple arrival streams of aircraft, passing through multiple merge points, from top-of-descent (TOD) to the Final Approach Fix. These arrival streams are Optimized Profile Descents (OPDs) from en route altitude to the runway, using primarily speed control to maintain separation and schedule. The ATD-1 project is currently addressing the challenges of integrating the three technologies, and their implantation into an operational environment. The ATD-1 goals include increasing the throughput of high-density airports, reducing controller workload, increasing efficiency of arrival operations and the frequency of trajectory-based operations, and promoting aircraft ADS-B equipage.

  16. Design of a Multi-mode Flight Deck Decision Support System for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Krishnamurthy, Karthik

    2004-01-01

    NASA Langley has developed a multi-mode decision support system for pilots operating in a Distributed Air-Ground Traffic Management (DAG-TM) environment. An Autonomous Operations Planner (AOP) assists pilots in performing separation assurance functions, including conflict detection, prevention, and resolution. Ongoing AOP design has been based on a comprehensive human factors analysis and evaluation results from previous human-in-the-loop experiments with airline pilot test subjects. AOP considers complex flight mode interactions and provides flight guidance to pilots consistent with the current aircraft control state. Pilots communicate goals to AOP by setting system preferences and actively probing potential trajectories for conflicts. To minimize training requirements and improve operational use, AOP design leverages existing alerting philosophies, displays, and crew interfaces common on commercial aircraft. Future work will consider trajectory prediction uncertainties, integration with the TCAS collision avoidance system, and will incorporate enhancements based on an upcoming air-ground coordination experiment.

  17. Traffic Management Based on Negotiations between Vehicles - A Feasibility Demonstration Using Agents

    NASA Astrophysics Data System (ADS)

    Schepperle, Heiko; Böhm, Klemens; Forster, Simone

    City governments currently make significant efforts to design traffic-control schemes. While existing solutions try to optimize the load of traffic resources, they do not consider one important aspect: Different drivers value short waiting times differently. For instance, the valuation of a truck driver who is part of a just-in-time production chain tends to be higher than the one of a family on an excursion for pleasure. Traffic-control schemes that give preference to drivers with higher valuations will increase the total utility of all drivers. In this paper we propose a new mechanism for traffic control at intersections. It is called Time-Slot Exchange and relies on bilateral negotiations. It tries to optimize the use of traffic resources in a valuation-aware fashion. The mechanism relies on agent-based driver-assistance systems with communication features which negotiate the right to cross an intersection at a certain time. Using simulations, we show that our new mechanism outperforms existing ones regarding average valuation-weighted waiting time.

  18. Force Reconnaissance: A Key Enabler in the Marine Air Ground Task Force and Beyond

    DTIC Science & Technology

    2012-03-13

    Marine Air Ground Task N/A Force & Beyond Sb. GRANT NUMBER N/A Sc. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR( S ) Sd. PROJECT NUMBER Carr, Bradford R...Major, USMC N/A Se. TASK NUMBER N/A Sf. WORK UNIT NUMBER N/A 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION USMC...Command and Staff College REPORT NUMBER Marine Corps University N/A 2076 South Street Quantico, VA 22134-5068 9. SPONSORING/MONITORING AGENCY NAME( S

  19. VHF Air/Ground Communications for Air Traffic Control: A Decision Tree Approach to System Innovations. Volume 2

    DTIC Science & Technology

    1993-07-01

    White, Warren J. Wilson 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION The MITRE Corporation REPORT NUMBER 202...Trafic Control, M92B0000017, The MITRE Corporation , February 1992. References for Section 9 1. Peterson, W. W. and E. J. Weldon Jr., Error-Correcting...7. Chen, C-H., Channel Bit-Error-Rate versus Packet Error Rate, Memo D053-M-1539, The MITRE Corporation , 9 December 1991. 8. Lin, S., and D. J

  20. Human-Centered Technologies and Procedures for Future Air Traffic Management: A Preliminary Overview of 1996 Studies and Results

    NASA Technical Reports Server (NTRS)

    Smith, Philip; McCoy, Elaine; Denning, Rebecca; Woods, David; Sarter, Nadine; Dekker, Sidney; Billings, Charles

    1996-01-01

    In this project, we have been exploring the use of a general methodology to predict the impact of future Air Traffic Management (ATM) concepts and technologies. In applying this methodology, our emphasis has been on the importance of modeling coordination and cooperation among the multiple agents within this system, and on understanding how the interactions among these agents will be influenced as new roles, responsibilities, procedures and technologies are introduced. To accomplish this, we have been collecting data on performance under the current air traffic management system, trying to identify critical problem areas and looking for exemplars suggestive of general approaches for solving such problems. Based on the results of these field studies, we have developed a set of scenarios centered around potential future system designs, and have conducted studies using these scenarios involving a total 40 controllers, dispatchers, pilots and traffic managers. The purpose of this report is to provide NASA with an early summary of the major recommendations that have resulted from our research under the AATT Program thus far. Recommendations 1-3 deal with general approaches that our findings suggest should be incorporated in future AATT Program activities, while Recommendations 4-11 identify some specific topics and technologies that merit research and development activities. Detailed technical reports containing supporting data, as well as the results of our still ongoing analyses, will be provided at a later date. The remainder of this report is organized as follows. Section 1 briefly describes the general design philosophy supported by our empirical studies. Section 2 presents the research methods we have used for identifying requirements for future system designs and for evaluating alternative design solutions. Section 3 discusses preliminary results from an initial set of investigations that we have conducted using these research methods. Section 4 then provides an

  1. Crash Injury Management for Traffic Law Enforcement Officers; Emergency Medical Services; Course Guide.

    ERIC Educational Resources Information Center

    Cleven, Arlene M.

    The course guide has been prepared to aid in planning and conducting a training program in emergency medical care for first responders to traffic accidents (expected to be patrolling law enforcement officers). This document contains a detailed description of the training program; suggestions for course planning including class size, scheduling…

  2. Crash Injury Management: Emergency Medical Services for Traffic Law Enforcement Officers. Instructor's Lesson Plans.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    To assist in the continuing efforts to improve the safety of the motorist on the nation's highways and roads, this instructor's guide provides a standardized approach for providing training in emergency medical care for first responders to traffic accidents. The objective of the course is to provide training in all aspects of emergency medical…

  3. A Method for Making Cross-Comparable Estimates of the Benefits of Decision Support Technologies for Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Lee, David; Long, Dou; Etheridge, Mel; Plugge, Joana; Johnson, Jesse; Kostiuk, Peter

    1998-01-01

    We present a general method for making cross comparable estimates of the benefits of NASA-developed decision support technologies for air traffic management, and we apply a specific implementation of the method to estimate benefits of three decision support tools (DSTs) under development in NASA's advanced Air Transportation Technologies Program: Active Final Approach Spacing Tool (A-FAST), Expedite Departure Path (EDP), and Conflict Probe and Trial Planning Tool (CPTP). The report also reviews data about the present operation of the national airspace system (NAS) to identify opportunities for DST's to reduce delays and inefficiencies.

  4. Optimal control of systems governed by differential equations with applications in air traffic management and systems biology

    NASA Astrophysics Data System (ADS)

    Raffard, Robin L.

    Differential equations are arguably the most widespread formalism to model dynamical systems in sciences and engineering. In this dissertation, we strive to design a practical methodology which can be used for the optimal control of most systems modeled by differential equations. Namely, the method is applicable to ordinary differential equations (ODEs), partial differential equations (PDEs) and stochastic differential equations (SDEs) driven by deterministic control. The algorithm draws from both optimization and control theory. It solves the Pontryagin Maximum Principle conditions in an iterative fashion via a novel approximate Newton method. We also extend the method to the case in which multiple agents are involved in the optimal control problem. For this purpose, we use dual decomposition techniques which allow us to decentralize the control algorithm and to distribute the computational load among each individual agent. Most of the dissertation is devoted to promoting the applicability of the method to practical problems in air traffic management and systems biology. In air traffic management; we use the technique to optimize a new PDE-based Eulerian model of the airspace; suitable to represent and control air traffic flow at the scale of the US national airspace. We also apply the technique to aircraft coordination problems in the context of formation flight, in which aircraft dynamics are described by ODEs. In systems biology, we use the method to perform fast parameter identification in the analysis of protein networks, which allows us to gain some insights about the biological processes regulating the system. In particular we perform parameter identification for a PDE model of a spatially distributed network of proteins, playing a key role in the planar cell polarity of Drosophila wings. We also study a general representation of intra-cellular genetic networks, described as a stochastic nonlinear regulatory network, in which our control system approach

  5. Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

    NASA Technical Reports Server (NTRS)

    Jain, Raj

    1999-01-01

    This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

  6. The future role of satellite communications in an improved air traffic management

    NASA Astrophysics Data System (ADS)

    Gauthier, Patrice

    1992-07-01

    The need for air to ground communication in Air Traffic Control (ATC) is discussed and a summary on the birth of aeronautical satellite communication is given. The standardization of an aeronautical mobile communications service by the International Civil Aviation Organization is reported. The feasibility analysis of satellite communications for ATC carried out by the French civil aviation is described. This 'South Pacific Trial' is regarded as a first step towards a full operational implementation.

  7. Advanced Air Traffic Management Research (Human Factors and Automation): NASA Research Initiatives in Human-Centered Automation Design in Airspace Management

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Condon, Gregory W. (Technical Monitor)

    1996-01-01

    NASA has initiated a significant thrust of research and development focused on providing the flight crew and air traffic managers automation aids to increase capacity in en route and terminal area operations through the use of flexible, more fuel-efficient routing, while improving the level of safety in commercial carrier operations. In that system development, definition of cognitive requirements for integrated multi-operator dynamic aiding systems is fundamental. The core processes of control and the distribution of decision making in that control are undergoing extensive analysis. From our perspective, the human operators and the procedures by which they interact are the fundamental determinants of the safe, efficient, and flexible operation of the system. In that perspective, we have begun to explore what our experience has taught will be the most challenging aspects of designing and integrating human-centered automation in the advanced system. We have performed a full mission simulation looking at the role shift to self-separation on board the aircraft with the rules of the air guiding behavior and the provision of a cockpit display of traffic information and an on-board traffic alert system that seamlessly integrates into the TCAS operations. We have performed and initial investigation of the operational impact of "Dynamic Density" metrics on controller relinquishing and reestablishing full separation authority. (We follow the assumption that responsibility at all times resides with the controller.) This presentation will describe those efforts as well as describe the process by which we will guide the development of error tolerant systems that are sensitive to shifts in operator work load levels and dynamic shifts in the operating point of air traffic management.

  8. Analysis of Factors for Incorporating User Preferences in Air Traffic Management: A system Perspective

    NASA Technical Reports Server (NTRS)

    Sheth, Kapil S.; Gutierrez-Nolasco, Sebastian

    2010-01-01

    This paper presents an analysis of factors that impact user flight schedules during air traffic congestion. In pre-departure flight planning, users file one route per flight, which often leads to increased delays, inefficient airspace utilization, and exclusion of user flight preferences. In this paper, first the idea of filing alternate routes and providing priorities on each of those routes is introduced. Then, the impact of varying planning interval and system imposed departure delay increment is discussed. The metrics of total delay and equity are used for analyzing the impact of these factors on increased traffic and on different users. The results are shown for four cases, with and without the optional routes and priority assignments. Results demonstrate that adding priorities to optional routes further improves system performance compared to filing one route per flight and using first-come first-served scheme. It was also observed that a two-hour planning interval with a five-minute system imposed departure delay increment results in highest delay reduction. The trend holds for a scenario with increased traffic.

  9. Antennas Designed for Advanced Communications for Air Traffic Management (AC/ATM) Project

    NASA Technical Reports Server (NTRS)

    Zakrajsek, Robert J.

    2000-01-01

    The goal of the Advanced Communications for Air Traffic Management (AC/ATM) Project at the NASA Glenn Research Center at Lewis Field is to enable a communications infrastructure that provides the capacity, efficiency, and flexibility necessary to realize a mature free-flight environment. The technical thrust of the AC/ATM Project is targeted at the design, development, integration, test, and demonstration of enabling technologies for global broadband aeronautical communications. Since Ku-band facilities and equipment are readily available, one of the near-term demonstrations involves a link through a Kuband communications satellite. Two conformally mounted antennas will support the initial AC/ATM communications links. Both of these are steered electronically through monolithic microwave integrated circuit (MMIC) amplifiers and phase shifters. This link will be asymmetrical with the downlink to the aircraft (mobile vehicle) at a throughput rate of greater than 1.5 megabits per second (Mbps), whereas the throughput rate of the uplink from the aircraft will be greater than 100 kilobits per second (kbps). The data on the downlink can be narrow-band, wide-band, or a combination of both, depending on the requirements of the experiment. The AC/ATM project is purchasing a phased-array Ku-band transmitting antenna for the uplink from the test vehicle. Many Ku-band receiving antennas have been built, and one will be borrowed for a short time to perform the initial experiments at the NASA Glenn Research Center at Lewis Field. The Ku-band transmitting antenna is a 254-element MMIC phased-array antenna being built by Boeing Phantom Works. Each element can radiate 100 mW. The antenna is approximately 43-cm high by 24-cm wide by 3.3-cm thick. It can be steered beyond 60 from broadside. The beamwidth varies from 6 at broadside to 12 degrees at 60 degrees, which is typical of phased-array antennas. When the antenna is steered to 60 degrees, the beamwidth will illuminate

  10. Air Traffic Management Technology Demostration Phase 1 (ATD) Interval Management for Near-Term Operations Validation of Acceptability (IM-NOVA) Experiment

    NASA Technical Reports Server (NTRS)

    Kibler, Jennifer L.; Wilson, Sara R.; Hubbs, Clay E.; Smail, James W.

    2015-01-01

    The Interval Management for Near-term Operations Validation of Acceptability (IM-NOVA) experiment was conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) in support of the NASA Airspace Systems Program's Air Traffic Management Technology Demonstration-1 (ATD-1). ATD-1 is intended to showcase an integrated set of technologies that provide an efficient arrival solution for managing aircraft using Next Generation Air Transportation System (NextGen) surveillance, navigation, procedures, and automation for both airborne and ground-based systems. The goal of the IMNOVA experiment was to assess if procedures outlined by the ATD-1 Concept of Operations were acceptable to and feasible for use by flight crews in a voice communications environment when used with a minimum set of Flight Deck-based Interval Management (FIM) equipment and a prototype crew interface. To investigate an integrated arrival solution using ground-based air traffic control tools and aircraft Automatic Dependent Surveillance-Broadcast (ADS-B) tools, the LaRC FIM system and the Traffic Management Advisor with Terminal Metering and Controller Managed Spacing tools developed at the NASA Ames Research Center (ARC) were integrated into LaRC's Air Traffic Operations Laboratory (ATOL). Data were collected from 10 crews of current 757/767 pilots asked to fly a high-fidelity, fixed-based simulator during scenarios conducted within an airspace environment modeled on the Dallas-Fort Worth (DFW) Terminal Radar Approach Control area. The aircraft simulator was equipped with the Airborne Spacing for Terminal Area Routes (ASTAR) algorithm and a FIM crew interface consisting of electronic flight bags and ADS-B guidance displays. Researchers used "pseudo-pilot" stations to control 24 simulated aircraft that provided multiple air traffic flows into the DFW International Airport, and recently retired DFW air traffic controllers served as confederate Center, Feeder, Final

  11. Handling Trajectory Uncertainties for Airborne Conflict Management

    NASA Technical Reports Server (NTRS)

    Barhydt, Richard; Doble, Nathan A.; Karr, David; Palmer, Michael T.

    2005-01-01

    Airborne conflict management is an enabling capability for NASA's Distributed Air-Ground Traffic Management (DAG-TM) concept. DAGTM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, autonomous aircraft maintain separation from each other and from managed aircraft unequipped for autonomous flight. NASA Langley Research Center has developed the Autonomous Operations Planner (AOP), an onboard decision support system that provides airborne conflict management (ACM) and strategic flight planning support for autonomous aircraft pilots. The AOP performs conflict detection, prevention, and resolution from nearby traffic aircraft and area hazards. Traffic trajectory information is assumed to be provided by Automatic Dependent Surveillance Broadcast (ADS-B). Reliable trajectory prediction is a key capability for providing effective ACM functions. Trajectory uncertainties due to environmental effects, differences in aircraft systems and performance, and unknown intent information lead to prediction errors that can adversely affect AOP performance. To accommodate these uncertainties, the AOP has been enhanced to create cross-track, vertical, and along-track buffers along the predicted trajectories of both ownship and traffic aircraft. These buffers will be structured based on prediction errors noted from previous simulations such as a recent Joint Experiment between NASA Ames and Langley Research Centers and from other outside studies. Currently defined ADS-B parameters related to navigation capability, trajectory type, and path conformance will be used to support the algorithms that generate the buffers.

  12. Simulation of the introduction of new technologies in air traffic management

    NASA Astrophysics Data System (ADS)

    Yliniemi, Logan; Agogino, Adrian K.; Tumer, Kagan

    2015-07-01

    Accurate simulation of the effects of integrating new technologies into a complex system is critical to the modernisation of large infrastructure problems. This is especially true in the modernisation of our antiquated air traffic system, where there exist many layers of interacting procedures, controls, and automation all designed to cooperate with human operators. Additions of even simple new technologies may result in unexpected emergent behaviour due to complex human/machine interactions. One approach is to create high-fidelity human models coming from the field of human factors that can simulate a rich set of behaviours. However, such models are difficult to produce, especially to show unexpected emergent behaviour coming from many human operators interacting simultaneously within a complex system. Instead, we introduce an alternate approach. Instead of engineering complex human models, we directly model the emergent behaviour with relatively simple goal-directed agents. In this model, each autonomous agent in a system pursues individual goals, and the high-level behaviour of the system emerges from the interactions, foreseen or unforeseen, between the agents/actors. We show that this method is capable of reflecting the integration of new technologies in a historical case, and apply the same methodology for a possible future technology. Finally, we show how these high-level simulated behaviours compare to actual deployed air traffic control mechanisms in use today.

  13. Evolutionary Agent-Based Simulation of the Introduction of New Technologies in Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Yliniemi, Logan; Agogino, Adrian K.; Tumer, Kagan

    2014-01-01

    Accurate simulation of the effects of integrating new technologies into a complex system is critical to the modernization of our antiquated air traffic system, where there exist many layers of interacting procedures, controls, and automation all designed to cooperate with human operators. Additions of even simple new technologies may result in unexpected emergent behavior due to complex human/ machine interactions. One approach is to create high-fidelity human models coming from the field of human factors that can simulate a rich set of behaviors. However, such models are difficult to produce, especially to show unexpected emergent behavior coming from many human operators interacting simultaneously within a complex system. Instead of engineering complex human models, we directly model the emergent behavior by evolving goal directed agents, representing human users. Using evolution we can predict how the agent representing the human user reacts given his/her goals. In this paradigm, each autonomous agent in a system pursues individual goals, and the behavior of the system emerges from the interactions, foreseen or unforeseen, between the agents/actors. We show that this method reflects the integration of new technologies in a historical case, and apply the same methodology for a possible future technology.

  14. Analysis and Simulation of Traffic Control for Resource Management in DVB-Based Broadband Satellite Access Networks

    NASA Astrophysics Data System (ADS)

    Impemba, Ernesto; Inzerilli, Tiziano

    2003-07-01

    Integration of satellite access networks with the Internet is seen as a strategic goal to achieve in order to provide ubiquitous broadband access to Internet services in Next Generation Networks (NGNs). One of the main interworking aspects which has been most studied is an efficient management of satellite resources, i.e. bandwidth and buffer space, in order to satisfy most demanding application requirements as to delay control and bandwidth assurance. In this context, resource management in DVB-S/DVB-RCS satellite technologies, emerging technologies for broadband satellite access and transport of IP applications, is a research issue largely investigated as a means to provide efficient bi-directional communications across satellites. This is in particular one of the principal goals of the SATIP6 project, sponsored within the 5th EU Research Programme Framework, i.e. IST. In this paper we present a possible approach to efficiently exploit bandwidth, the most critical resource in a broadband satellite access network, while pursuing satisfaction of delay and bandwidth requirements for applications with guaranteed QoS through a traffic control architecture to be implemented in ground terminals. Performance of this approach is assessed in terms of efficient exploitation of the uplink bandwidth and differentiation and minimization of queuing delays for most demanding applications over a time-varying capacity. Opnet simulations is used as analysis tool.

  15. The performance evaluation of a new neural network based traffic management scheme for a satellite communication network

    NASA Technical Reports Server (NTRS)

    Ansari, Nirwan; Liu, Dequan

    1991-01-01

    A neural-network-based traffic management scheme for a satellite communication network is described. The scheme consists of two levels of management. The front end of the scheme is a derivation of Kohonen's self-organization model to configure maps for the satellite communication network dynamically. The model consists of three stages. The first stage is the pattern recognition task, in which an exemplar map that best meets the current network requirements is selected. The second stage is the analysis of the discrepancy between the chosen exemplar map and the state of the network, and the adaptive modification of the chosen exemplar map to conform closely to the network requirement (input data pattern) by means of Kohonen's self-organization. On the basis of certain performance criteria, whether a new map is generated to replace the original chosen map is decided in the third stage. A state-dependent routing algorithm, which arranges the incoming call to some proper path, is used to make the network more efficient and to lower the call block rate. Simulation results demonstrate that the scheme, which combines self-organization and the state-dependent routing mechanism, provides better performance in terms of call block rate than schemes that only have either the self-organization mechanism or the routing mechanism.

  16. Unmanned Aerial Systems Traffic Management (UTM): Safely Enabling UAS Operations in Low-Altitude Airspace

    NASA Technical Reports Server (NTRS)

    Kopardekar, Parimal H.; Cavolowsky, John

    2015-01-01

    Flexibility where possible, and structure where necessary. Consider the needs of national security, safe airspace operations, economic opportunities, and emerging technologies. Risk-based approach based on population density, assets on the ground, density of operations, etc. Digital, virtual, dynamic, and as needed UTM services to manage operations.

  17. Military Traffic Management Command Financial Reporting of Property, Plant, and Equipment.

    DTIC Science & Technology

    2007-11-02

    1996 balances in the MTMC property, plant, and equipment accounts. We also assessed management controls as they applied to the overall audit objective...The MTMC attempted to improve its reporting of property, plant, and equipment values for the FY 1996 Defense Business Operations Fund financial...statements. To that end, MTMC reconciled logistics records with financial records, noted changes, and reported the changes to the Defense Finance and

  18. Development and evaluation of a profile negotiation process for integrating aircraft and air traffic control automation

    NASA Technical Reports Server (NTRS)

    Green, Steven M.; Denbraven, Wim; Williams, David H.

    1993-01-01

    The development and evaluation of the profile negotiation process (PNP), an interactive process between an aircraft and air traffic control (ATC) that integrates airborne and ground-based automation capabilities to determine conflict-free trajectories that are as close to an aircraft's preference as possible, are described. The PNP was evaluated in a real-time simulation experiment conducted jointly by NASA's Ames and Langley Research Centers. The Ames Center/TRACON Automation System (CTAS) was used to support the ATC environment, and the Langley Transport Systems Research Vehicle (TSRV) piloted cab was used to simulate a 4D Flight Management System (FMS) capable aircraft. Both systems were connected in real time by way of voice and data lines; digital datalink communications capability was developed and evaluated as a means of supporting the air/ground exchange of trajectory data. The controllers were able to consistently and effectively negotiate nominally conflict-free vertical profiles with the 4D-equipped aircraft. The actual profiles flown were substantially closer to the aircraft's preference than would have been possible without the PNP. However, there was a strong consensus among the pilots and controllers that the level of automation of the PNP should be increased to make the process more transparent. The experiment demonstrated the importance of an aircraft's ability to accurately execute a negotiated profile as well as the need for digital datalink to support advanced air/ground data communications. The concept of trajectory space is proposed as a comprehensive approach for coupling the processes of trajectory planning and tracking to allow maximum pilot discretion in meeting ATC constraints.

  19. Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

    NASA Technical Reports Server (NTRS)

    Shamma, Mohammed A.

    2004-01-01

    The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

  20. Vessel traffic patterns in the Port of Kaohsiung and the management implications for preventing the introduction of non-indigenous aquatic species.

    PubMed

    Liu, Ta-Kang; Tsai, Tzung-Kuen

    2011-03-01

    Data on shipping traffic in one of the busiest seaports in the world, the Port of Kaohsiung, were analyzed to evaluate the implications for ballast water management. Results show that 67% of the arriving vessels were registered to a flag of convenience, which typically have a lower degree of environmental records. The top five donor countries historically suffer from harmful algal bloom problems. The short journey and busy trading between these countries and Taiwan lead to a higher risk of inoculation. In addition, only 1.4% of all vessels visited more than once every year during the 9-year span, indicating that the port authority encounters many new vessels each year. These findings could influence the design and application of ballast water management strategies as well as highlight the challenges in their implementation. We suggest that an analysis of vessel traffic patterns should be coupled with other useful vessel information to make risk assessment successful.

  1. MAGTF (Marine Air Ground Task Force) Data Transfer Alternatives (1986-1996).

    DTIC Science & Technology

    1986-04-01

    to test extremes which cannot be accomplished in exercises. It is recommended that testing of existing systems be initiated through development of...information exchange " "standards and units of measurement and a computer model to test manual traffic analyses and simulate extremes which cannot be...capability will also be added. Two planned procurements of ADPE-FMF devices will have these characteristics. Operational Testing and Evaluation (OT&E) of

  2. Traffic Monitor

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Mestech's X-15 "Eye in the Sky," a traffic monitoring system, incorporates NASA imaging and robotic vision technology. A camera or "sensor box" is mounted in a housing. The sensor detects vehicles approaching an intersection and sends the information to a computer, which controls the traffic light according to the traffic rate. Jet Propulsion Laboratory technical support packages aided in the company's development of the system. The X-15's "smart highway" can also be used to count vehicles on a highway and compute the number in each lane and their speeds, important information for freeway control engineers. Additional applications are in airport and railroad operations. The system is intended to replace loop-type traffic detectors.

  3. Feasibility of using frequency offset on very high frequency air/ground voice channels

    NASA Astrophysics Data System (ADS)

    Badinelli, Martin; Cushman, Arthur; Randazzo, Philip

    1990-03-01

    In some large Federal Aviation Administration (FAA) air traffic control sectors, the controller manually switches between multiple ground transmitters to communicate with aircraft at opposite ends of the sector. This puts an additional burden on the controller. Aeronautical Radio, Inc. (ARINC) uses a frequency offset system which produces five frequencies from one channel assignment. ARINC provides this service to commercial air carriers who use receivers designed to ARINC specifications. These receivers are capable of eliminating the audio heterodyne generated by the offsetting process. The commercial air carriers use this system for airline business. The testing performed at the FAA Technical Center to evaluate this system as a means of controlling the air traffic in large sectors is described. The tests indicate that a frequency offset system cannot be used with general aviation aircraft receivers because many cannot filter out the audio heterodyne. Use of frequency offset may be possible in high altitude sectors where commercial aviation receivers, which meet ARINC specifications, are used if some additional concerns are resolved.

  4. Computational Models of Human Performance: Validation of Memory and Procedural Representation in Advanced Air/Ground Simulation

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Labacqz, J. Victor (Technical Monitor)

    1997-01-01

    The Man-Machine Interaction Design and Analysis System (MIDAS) under joint U.S. Army and NASA cooperative is intended to assist designers of complex human/automation systems in successfully incorporating human performance capabilities and limitations into decision and action support systems. MIDAS is a computational representation of multiple human operators, selected perceptual, cognitive, and physical functions of those operators, and the physical/functional representation of the equipment with which they operate. MIDAS has been used as an integrated predictive framework for the investigation of human/machine systems, particularly in situations with high demands on the operators. We have extended the human performance models to include representation of both human operators and intelligent aiding systems in flight management, and air traffic service. The focus of this development is to predict human performance in response to aiding system developed to identify aircraft conflict and to assist in the shared authority for resolution. The demands of this application requires representation of many intelligent agents sharing world-models, coordinating action/intention, and cooperative scheduling of goals and action in an somewhat unpredictable world of operations. In recent applications to airborne systems development, MIDAS has demonstrated an ability to predict flight crew decision-making and procedural behavior when interacting with automated flight management systems and Air Traffic Control. In this paper, we describe two enhancements to MIDAS. The first involves the addition of working memory in the form of an articulatory buffer for verbal communication protocols and a visuo-spatial buffer for communications via digital datalink. The second enhancement is a representation of multiple operators working as a team. This enhanced model was used to predict the performance of human flight crews and their level of compliance with commercial aviation communication

  5. State Traffic Data: Traffic Safety Facts, 2001.

    ERIC Educational Resources Information Center

    National Center for Statistics and Analysis (NHTSA), Washington, DC.

    This brief provides statistical information on U.S. traffic accidents delineated by state. A map details the 2001 traffic fatalities by state and the percent change from 2000. Data tables include: (1) traffic fatalities and fatality rates, 2001; (2) traffic fatalities and percent change, 1975-2001; (3) alcohol involvement in fatal traffic crashes,…

  6. Transportation and Traffic Management

    DTIC Science & Technology

    1989-01-26

    the requesting activity. b. DoD Car Rental Program. HThC is responsible for all DoD car rental programs. Rental car arrangements shall be made through...commercial travel offices (CTOs), when available, to ensure the lowest rate and comprehensive reporting on rental car use. If arrangements cannot be...made through CTOs, DoD travelers shall select a car rental service that accomplishes the mission at the lowest overall cost to the Government. To

  7. Assessment and management of human health risk from toxic metals and polycyclic aromatic hydrocarbons in urban stormwater arising from anthropogenic activities and traffic congestion.

    PubMed

    Ma, Yukun; Liu, An; Egodawatta, Prasanna; McGree, James; Goonetilleke, Ashantha

    2017-02-01

    Toxic metals (TMs) and polycyclic aromatic hydrocarbons (PAHs) in urban stormwater pose risk to human health, thereby constraining its reuse potential. Based on the hypothesis that stormwater quality is primarily influenced by anthropogenic activities and traffic congestion, the primary focus of the research study was to analyse the impacts on human health risk from TMs and PAHs in urban stormwater and thereby develop a quantitative risk assessment model. The study found that anthropogenic activities and traffic congestion exert influence on the risk posed by TMs and PAHs in stormwater from commercial and residential areas. Motor vehicle related businesses (FVS) and traffic congestion (TC) were identified as two parameters which need to be included as independent variables to improve the model. Based on the study outcomes, approaches for mitigating the risk associated with TMs and PAHs in urban stormwater are discussed. Additionally, a roadmap is presented for the assessment and management of the risk arising from these pollutants. The study outcomes are expected to contribute to reducing the human health risk associated urban stormwater pollution and thereby enhance its reuse potential.

  8. Traffic Driven Analysis of Cellular and WiFi Networks

    ERIC Educational Resources Information Center

    Paul, Utpal Kumar

    2012-01-01

    Since the days Internet traffic proliferated, measurement, monitoring and analysis of network traffic have been critical to not only the basic understanding of large networks, but also to seek improvements in resource management, traffic engineering and security. At the current times traffic in wireless local and wide area networks are facing…

  9. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Vessel Traffic Service Louisville... (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.30 Vessel Traffic Service Louisville. The VTS...

  10. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Vessel Traffic Service Louisville... (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.30 Vessel Traffic Service Louisville. The VTS...

  11. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Vessel Traffic Service Louisville... (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.30 Vessel Traffic Service Louisville. The VTS...

  12. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Vessel Traffic Service Louisville... (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.30 Vessel Traffic Service Louisville. The VTS...

  13. 33 CFR 161.30 - Vessel Traffic Service Louisville.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vessel Traffic Service Louisville... (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.30 Vessel Traffic Service Louisville. The VTS...

  14. TrafficGen Architecture Document

    DTIC Science & Technology

    2016-01-01

    v 1. Overview of TrafficGen Application 1 2. Modules 2 3. User Interface 3 3.1 Top-Level MVC Classes 3 3.1.1 TrafficGenView 3 3.1.2...release; distribution unlimited. 3 A key design concept in use here is the model-view-controller ( MVC ) pattern. In general, the MVC design pattern...and easier to manage. MVC facilitates reuse by reducing and formalizing coupling between model components and the user interface. The same TrafficGen

  15. Traffic Monitor

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Intelligent Vision Systems, Inc. (InVision) needed image acquisition technology that was reliable in bad weather for its TDS-200 Traffic Detection System. InVision researchers used information from NASA Tech Briefs and assistance from Johnson Space Center to finish the system. The NASA technology used was developed for Earth-observing imaging satellites: charge coupled devices, in which silicon chips convert light directly into electronic or digital images. The TDS-200 consists of sensors mounted above traffic on poles or span wires, enabling two sensors to view an intersection; a "swing and sway" feature to compensate for movement of the sensors; a combination of electronic shutter and gain control; and sensor output to an image digital signal processor, still frame video and optionally live video.

  16. Development and test results of a flight management algorithm for fuel conservative descents in a time-based metered traffic environment

    NASA Technical Reports Server (NTRS)

    Knox, C. E.; Cannon, D. G.

    1980-01-01

    A simple flight management descent algorithm designed to improve the accuracy of delivering an airplane in a fuel-conservative manner to a metering fix at a time designated by air traffic control was developed and flight tested. This algorithm provides a three dimensional path with terminal area time constraints (four dimensional) for an airplane to make an idle thrust, clean configured (landing gear up, flaps zero, and speed brakes retracted) descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path was calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithm is described. The results of the flight tests flown with the Terminal Configured Vehicle airplane are presented.

  17. Real-Time Surface Traffic Adviser

    NASA Technical Reports Server (NTRS)

    Glass, Brian J. (Inventor); Spirkovska, Liljana (Inventor); McDermott, William J. (Inventor); Reisman, Ronald J. (Inventor); Gibson, James (Inventor); Iverson, David L. (Inventor)

    2001-01-01

    A real-time data management system which uses data generated at different rates by multiple heterogeneous incompatible data sources are presented. In one embodiment, the invention is as an airport surface traffic data management system (traffic adviser) that electronically interconnects air traffic control, airline, and airport operations user communities to facilitate information sharing and improve taxi queuing. The system uses an expert system to fuse dam from a variety of airline, airport operations, ramp control, and air traffic control sources, in order to establish, predict, and update reference data values for every aircraft surface operation.

  18. Plan Maintenance for Continuous Execution Management: Planning, Plan Repair, Execution Monitoring

    DTIC Science & Technology

    2010-06-01

    contribution on the Joint Air/Ground Operations Unified Adaptive Replanning ( JAGUAR ) program. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17...and contribution on the Joint Air/Ground Operations Unified Adaptive Replanning ( JAGUAR ) program. I. INTRODUCTION The Artificial Intelligence (AI...Operations Unified Adaptive Replanning ( JAGUAR ), a semi-automated system targeted towards oversight and management of a large number of interdependent

  19. Proof-of-Concept of a Networked Validation Environment for Distributed Air/Ground NextGen Concepts

    NASA Technical Reports Server (NTRS)

    Grisham, James; Larson, Natalie; Nelson, Justin; Reed, Joshua; Suggs, Marvin; Underwood, Matthew; Papelis, Yiannis; Ballin, Mark G.

    2013-01-01

    The National Airspace System (NAS) must be improved to increase capacity, reduce flight delays, and minimize environmental impacts of air travel. NASA has been tasked with aiding the Federal Aviation Administration (FAA) in NAS modernization. Automatic Dependent Surveillance-Broadcast (ADS-B) is an enabling technology that is fundamental to realization of the Next Generation Air Transportation System (NextGen). Despite the 2020 FAA mandate requiring ADS-B Out equipage, airspace users are lacking incentives to equip with the requisite ADS-B avionics. A need exists to validate in flight tests advanced concepts of operation (ConOps) that rely on ADS-B and other data links without requiring costly equipage. A potential solution is presented in this paper. It is possible to emulate future data link capabilities using the existing in-flight Internet and reduced-cost test equipment. To establish proof-of-concept, a high-fidelity traffic operations simulation was modified to include a module that simulated Internet transmission of ADS-B messages. An advanced NASA ConOp, Flight Deck Interval Management (FIM), was used to evaluate technical feasibility. A preliminary assessment of the effects of latency and dropout rate on FIM was performed. Flight hardware that would be used by proposed test environment was connected to the simulation so that data transfer from aircraft systems to test equipment could be verified. The results indicate that the FIM ConOp, and therefore, many other advanced ConOps with equal or lesser response characteristics and data requirements, can be evaluated in flight using the proposed concept.

  20. A review of the program of the Office of the Commission for the Management of Road Traffic

    SciTech Connect

    Saraswadi, K.

    1995-12-31

    This report describes the development of a Mass Rapid Transit Systems Master Plan by the Office for the Commission of Road Traffic (OCMRT) for Bangkok as detailed in the full Master Plan document. The Master Plan document addresses the following topic areas: evolution of the Master Plan Concept; socio-economic and development benefits; transport model development and applications; ridership findings; environmental considerations; capital and operating costs; economic and financial analysis findings; priority projects and construction program phasing; and implementation of the Master Plan - institutional issues. Each of these topics is discussed in further detail in its own chapter in the document. For purposes of this workshop and subsequent proceedings, the last section is highlighed in this presentation.

  1. Cascade connection serial parallel hybrid acquisition synchronization method for DS-FHSS in air-ground data link

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Zhou, Desuo

    2007-11-01

    In air-ground tactical data link system, a kind of primary anti jamming technology adopted is direct sequence - frequency hopping spread spectrum (DS-FHSS) technology. However, how to implement the quick synchronization of DS-FHSS is an important technology problem, which could influence the whole communication capability of system. Thinking of the application demand of anti jamming technology in actual, a kind of cascade connection serial parallel hybrid acquisition synchronization method is given for the DS-FHSS system. The synchronization consists of two stages. The synchronization of FH communication is adopted at the first stage, and the serial parallel hybrid structure is adopted for the DS PN code synchronization at the secondary stage. Through calculating the detect probability of the FH synchronization acquisition and the acquisition time of DS code chip synchronization, the contribution to the synchronization capability of system by this method in this paper is analyzed. Finally, through simulating on computer, the performance estimate about this cascade connection serial parallel hybrid acquisition synchronization method is given.

  2. Bayesian neural networks for internet traffic classification.

    PubMed

    Auld, Tom; Moore, Andrew W; Gull, Stephen F

    2007-01-01

    Internet traffic identification is an important tool for network management. It allows operators to better predict future traffic matrices and demands, security personnel to detect anomalous behavior, and researchers to develop more realistic traffic models. We present here a traffic classifier that can achieve a high accuracy across a range of application types without any source or destination host-address or port information. We use supervised machine learning based on a Bayesian trained neural network. Though our technique uses training data with categories derived from packet content, training and testing were done using features derived from packet streams consisting of one or more packet headers. By providing classification without access to the contents of packets, our technique offers wider application than methods that require full packet/payloads for classification. This is a powerful advantage, using samples of classified traffic to permit the categorization of traffic based only upon commonly available information.

  3. SIG: Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    NASA Technical Reports Server (NTRS)

    Feary, Michael; Palanque, Philippe; Martinie, Célia; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  4. Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    NASA Technical Reports Server (NTRS)

    Feary, Michael S.; Palanque, Philippe Andre Rolan; Martinie, De Almeida; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault-tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  5. Jamitons: Phantom Traffic Jams

    ERIC Educational Resources Information Center

    Kowszun, Jorj

    2013-01-01

    Traffic on motorways can slow down for no apparent reason. Sudden changes in speed by one or two drivers can create a chain reaction that causes a traffic jam for the vehicles that are following. This kind of phantom traffic jam is called a "jamiton" and the article discusses some of the ways in which traffic engineers produce…

  6. A knowledge-based system for controlling automobile traffic

    NASA Technical Reports Server (NTRS)

    Maravas, Alexander; Stengel, Robert F.

    1994-01-01

    Transportation network capacity variations arising from accidents, roadway maintenance activity, and special events as well as fluctuations in commuters' travel demands complicate traffic management. Artificial intelligence concepts and expert systems can be useful in framing policies for incident detection, congestion anticipation, and optimal traffic management. This paper examines the applicability of intelligent route guidance and control as decision aids for traffic management. Basic requirements for managing traffic are reviewed, concepts for studying traffic flow are introduced, and mathematical models for modeling traffic flow are examined. Measures for quantifying transportation network performance levels are chosen, and surveillance and control strategies are evaluated. It can be concluded that automated decision support holds great promise for aiding the efficient flow of automobile traffic over limited-access roadways, bridges, and tunnels.

  7. On urban road traffic state evaluation index system and method

    NASA Astrophysics Data System (ADS)

    Su, Fei; Dong, Honghui; Jia, Limin; Sun, Xuan

    2017-01-01

    Traffic state evaluation is a basic and critical work in the research on road traffic congestion. It can provide basic data support for the improvement measures and information release in traffic management and service. The aim of this research is to obtain a comprehensive value to describe traffic state accurately based on the evaluation index system. In this paper, it is carried out using fuzzy c-means (FCM) algorithm and fuzzy entropy weight method. In the framework, traffic flow was classified into six different states to determine the fuzzy range of indices using the improved FCM clustering analysis. Besides, fuzzy entropy weight method is proposed to compute the evaluation result of traffic state for section, road and road network, respectively. The experiments based on the traffic information in a subset of Beijing’s road network prove that the findings of traffic evaluation are in accordance with the actual situation and people’s sense of traffic state.

  8. 76 FR 31230 - Vessel Traffic Service Lower Mississippi River; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ... SECURITY Coast Guard 33 CFR Part 161 RIN 1625-AA58 Vessel Traffic Service Lower Mississippi River... participation Vessel Traffic Service (VTS) on the Lower Mississippi River and transferring certain vessel traffic management provisions of the Mississippi River, Louisiana--Regulated Navigation Area to the...

  9. Transforming the NAS: The Next Generation Air Traffic Control System

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2004-01-01

    The next-generation air traffic control system must be designed to safely and efficiently accommodate the large growth of traffic expected in the near future. It should be sufficiently scalable to contend with the factor of 2 or more increase in demand expected by the year 2020. Analysis has shown that the current method of controlling air traffic cannot be scaled up to provide such levels of capacity. Therefore, to achieve a large increase in capacity while also giving pilots increased freedom to optimize their flight trajectories requires a fundamental change in the way air traffic is controlled. The key to achieving a factor of 2 or more increase in airspace capacity is to automate separation monitoring and control and to use an air-ground data link to send trajectories and clearances directly between ground-based and airborne systems. In addition to increasing capacity and offering greater flexibility in the selection of trajectories, this approach also has the potential to increase safety by reducing controller and pilot errors that occur in routine monitoring and voice communication tasks.

  10. Methods of Modeling the Bicycle Traffic Flows on the Roundabouts

    NASA Astrophysics Data System (ADS)

    Macioszek, Elżbieta; Sierpiński, Grzegorz; Czapkowski, Leszek

    The paper deals with the bicycle traffic issues on the roundabouts and their nearby areas. The fundamental elements of traffic management and infrastructure used in traffic regulation on the roundabouts have been presented. The authors present also the examples of typical settings of the bicycle paths. Amongst the conventional solutions some interesting ones from abroad, from the Netherlands in particular, which grant a huge level of traffic safety while crossing a roundabout, have also been introduced.

  11. Parental Management of Teen Drivers after Receiving Their First Traffic Citation and Having Attended the 4-H CARTEENS Program

    ERIC Educational Resources Information Center

    Jordan, James Lawrence

    2010-01-01

    The United States is a vehicle-dependent society and allows teens to obtain drivers licenses at age 16 or younger. Many factors have been linked to teen risky driving behaviors that resulted in teens receiving their first citations. This was the first study to investigate parental management of teens after they received their first citations…

  12. 77 FR 28455 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... Management and Budget for each collection of information they conduct, sponsor, or require through...--Transportation, Highways and roads, Incorporation by reference, Pavement Markings, Traffic regulations. Issued...

  13. Distributed traffic signal control using fuzzy logic

    NASA Technical Reports Server (NTRS)

    Chiu, Stephen

    1992-01-01

    We present a distributed approach to traffic signal control, where the signal timing parameters at a given intersection are adjusted as functions of the local traffic condition and of the signal timing parameters at adjacent intersections. Thus, the signal timing parameters evolve dynamically using only local information to improve traffic flow. This distributed approach provides for a fault-tolerant, highly responsive traffic management system. The signal timing at an intersection is defined by three parameters: cycle time, phase split, and offset. We use fuzzy decision rules to adjust these three parameters based only on local information. The amount of change in the timing parameters during each cycle is limited to a small fraction of the current parameters to ensure smooth transition. We show the effectiveness of this method through simulation of the traffic flow in a network of controlled intersections.

  14. 33 CFR 161.45 - Vessel Traffic Service St. Marys River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Vessel Traffic Service St. Marys... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY VESSEL TRAFFIC MANAGEMENT Vessel Traffic Service and Vessel Movement Reporting System Areas and Reporting Points § 161.45 Vessel Traffic Service St. Marys River....

  15. Potential effects of the introduction of the discrete address beacon system data link on air/ground information transfer problems

    NASA Technical Reports Server (NTRS)

    Grayson, R. L.

    1981-01-01

    This study of Aviation Safety Reporting System reports suggests that benefits should accure from implementation of discrete address beacon system data link. The phase enhanced terminal information system service is expected to provide better terminal information than present systems by improving currency and accuracy. In the exchange of air traffic control messages, discrete address insures that only the intended recipient receives and acts on a specific message. Visual displays and printer copy of messages should mitigate many of the reported problems associated with voice communications. The problems that remain unaffected include error in addressing the intended recipient and messages whose content is wrong but are otherwise correct as to format and reasonableness.

  16. Analysis of Yearly Traffic Fluctuation on Latvian Highways

    NASA Astrophysics Data System (ADS)

    Freimanis, A.; Paeglı¯tis, A.

    2015-11-01

    Average annual daily traffic and average annual truck traffic are two most used metrics for road management decisions. They are calculated from data gathered by continuous counting stations embedded in road pavement, manual counting sessions or mobile counting devices. Last two usually do not last longer than a couple of weeks so the information gathered is influenced by yearly traffic fluctuations. Data containing a total of 8,186,871 vehicles or 1989 days from 4 WIM stations installed on highways in Latvia were used in this study. Each of the files was supposed to contain data from only 1 day and additional data were deleted. No other data cleaning steps were performed, which increased the number of vehicles as counting systems sometimes split vehicles into two. Weekly traffic and weekly truck traffic was normalized against respective average values. Each weekly value was then plotted against its number in a year for better visual perception. Weekly traffic amplitudes were used to assess differences between different locations and standard deviations for fluctuation comparison of truck and regular traffic at the same location. Results show that truck traffic fluctuates more than regular traffic during a year, especially around holidays. Differences between counting locations were larger for regular traffic than truck traffic. These results show that average annual daily traffic could be influenced more if short term counting results are adjusted by factors derived from unsuitable continuous counting stations, but truck traffic is more influenced by the time of year in which counting is done.

  17. Traffic Flow Wide-Area Surveillance system

    SciTech Connect

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.

    1994-09-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret a large spatial projection of data originating from multiple sensor suites. This concept is the basis for the development of a Traffic Flow Wide-Area Surveillance (TFWAS) system. This paper presents the results of a study by Oak Ridge National Laboratory to define the operational specifications and characteristics, to determine the constraints, and to examine the state of technology of a TFWAS system in terms of traffic management and control. In doing so, the functions and attributes of a TFWAS system are mapped into an operational structure consistent with the Intelligent Vehicle Highway System (IVHS) concept and the existing highway infrastructure. This mapping includes identifying candidate sensor suites and establishing criteria, requirements, and performance measures by which these systems can be graded in their ability and practicality to meet the operational requirements of a TFWAS system. In light of this, issues such as system integration, applicable technologies, impact on traffic management and control, and public acceptance are addressed.

  18. Preliminary test results of a flight management algorithm for fuel conservative descents in a time based metered traffic environment. [flight tests of an algorithm to minimize fuel consumption of aircraft based on flight time

    NASA Technical Reports Server (NTRS)

    Knox, C. E.; Cannon, D. G.

    1979-01-01

    A flight management algorithm designed to improve the accuracy of delivering the airplane fuel efficiently to a metering fix at a time designated by air traffic control is discussed. The algorithm provides a 3-D path with time control (4-D) for a test B 737 airplane to make an idle thrust, clean configured descent to arrive at the metering fix at a predetermined time, altitude, and airspeed. The descent path is calculated for a constant Mach/airspeed schedule from linear approximations of airplane performance with considerations given for gross weight, wind, and nonstandard pressure and temperature effects. The flight management descent algorithms and the results of the flight tests are discussed.

  19. Traffic at the edge of chaos

    SciTech Connect

    Nagel, K. ||; Rasmussen, S. |

    1994-09-01

    We use a very simple description of human driving behavior to simulate traffic. The regime of maximum vehicle flow in a closed system shows near-critical behavior, and as a result a sharp decrease of the predictability of travel time. Since Advanced Traffic Management Systems (ATMSs) tend to drive larger parts of the transportation system towards this regime of maximum flow, we argue that in consequence the traffic system as a whole will be driven closer to criticality, thus making predictions much harder. A simulation of a simplified transportation network supports our argument.

  20. 44 CFR 15.14 - Vehicular and pedestrian traffic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... traffic. 15.14 Section 15.14 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY... NATIONAL EMERGENCY TRAINING CENTER § 15.14 Vehicular and pedestrian traffic. (a) Drivers of all vehicles... signals and directions of the Police/Security Force or other authorized officials and all posted...

  1. Evidence toward an expanded international civil aviation organization (ICAO) concept of a single unified global communication navigation surveillance air traffic management (CNS/ATM) system: A quantitative analysis of ADS-B technology within a CNS/ATM system

    NASA Astrophysics Data System (ADS)

    Gardner, Gregory S.

    This research dissertation summarizes research done on the topic of global air traffic control, to include technology, controlling world organizations and economic considerations. The International Civil Aviation Organization (ICAO) proposed communication, navigation, surveillance, air traffic management system (CNS/ATM) plan is the basis for the development of a single global CNS/ATM system concept as it is discussed within this study. Research will be evaluated on the efficacy of a single technology, Automatic Dependent Surveillance-Broadcast (ADS-B) within the scope of a single global CNS/ATM system concept. ADS-B has been used within the Federal Aviation Administration's (FAA) Capstone program for evaluation since the year 2000. The efficacy of ADS-B was measured solely by using National Transportation Safety Board (NTSB) data relating to accident and incident rates within the Alaskan airspace (AK) and that of the national airspace system (NAS).

  2. Software for Simulating Air Traffic

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Bilimoria, Karl; Grabbe, Shon; Chatterji, Gano; Sheth, Kapil; Mulfinger, Daniel

    2006-01-01

    Future Air Traffic Management Concepts Evaluation Tool (FACET) is a system of software for performing computational simulations for evaluating advanced concepts of advanced air-traffic management. FACET includes a program that generates a graphical user interface plus programs and databases that implement computational models of weather, airspace, airports, navigation aids, aircraft performance, and aircraft trajectories. Examples of concepts studied by use of FACET include aircraft self-separation for free flight; prediction of air-traffic-controller workload; decision support for direct routing; integration of spacecraft-launch operations into the U.S. national airspace system; and traffic- flow-management using rerouting, metering, and ground delays. Aircraft can be modeled as flying along either flight-plan routes or great-circle routes as they climb, cruise, and descend according to their individual performance models. The FACET software is modular and is written in the Java and C programming languages. The architecture of FACET strikes a balance between flexibility and fidelity; as a consequence, FACET can be used to model systemwide airspace operations over the contiguous U.S., involving as many as 10,000 aircraft, all on a single desktop or laptop computer running any of a variety of operating systems. Two notable applications of FACET include: (1) reroute conformance monitoring algorithms that have been implemented in one of the Federal Aviation Administration s nationally deployed, real-time, operational systems; and (2) the licensing and integration of FACET with the commercially available Flight Explorer, which is an Internet- based, real-time flight-tracking system.

  3. Airborne Conflict Management within Confined Airspace in a Piloted Simulation of DAG-TM Autonomous Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan; Johnson, Edward; Wing, David J.; Barhydt, Richard

    2003-01-01

    A human-in-the-loop experiment was performed at the NASA Langley Research Center to study the feasibility of Distributed Air/Ground Traffic Management (DAG-TM) autonomous aircraft operations in highly constrained airspace. The airspace was constrained by a pair of special use airspace (SUA) regions on either side of the pilot s planned route. The available airspace was further varied by changing the separation standard for lateral separation between 3 nm and 5 nm. The pilot had to maneuver through the corridor between the SUA s, avoid other traffic and meet flow management constraints. Traffic flow management (TFM) constraints were imposed as a required time of arrival and crossing altitude at an en route fix. This is a follow-up study to work presented at the 4th USA/Europe Air Traffic Management R&D Seminar in December 2001. Nearly all of the pilots were able to meet their TFM constraints while maintaining adequate separation from other traffic. In only 3 out of 59 runs were the pilots unable to meet their required time of arrival. Two loss of separation cases are studied and it is found that the pilots need conflict prevention information presented in a clearer manner. No degradation of performance or safety was seen between the wide and narrow corridors. Although this was not a thorough study of the consequences of reducing the en route lateral separation, nothing was found that would refute the feasibility of reducing the separation requirement from 5 nm to 3 nm. The creation of additional, second-generation conflicts is also investigated. Two resolution methods were offered to the pilots: strategic and tactical. The strategic method is a closed-loop alteration to the Flight Management System (FMS) active route that considers other traffic as well as TFM constraints. The tactical resolutions are short-term resolutions that leave avoiding other traffic conflicts and meeting the TFM constraints to the pilot. Those that made use of the strategic tools avoided

  4. NASA Now: Air Traffic Management

    NASA Video Gallery

    In this episode of NASA Now, you’ll meet aerospace engineer Aisha Bowe, who is helping NASA solve this complex problem. Learn why there is no perfectly designed system and all technological solut...

  5. Remote sensing applications for transportation and traffic engineering studies: A review of the literature

    NASA Technical Reports Server (NTRS)

    Epps, J. W.

    1973-01-01

    Current references were surveyed for the application of remote sensing to traffic and transportation studies. The major problems are presented that concern traffic engineers and transportation managers, and the literature references that discuss remote sensing applications are summarized.

  6. Trafficability and workability of soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trafficability and workability are soil capabilities supporting operations of agricultural machinery. Trafficability is a soil's capability to support agricultural traffic without degrading soils and ecosystems. Workability is a soil capability supporting tillage. Agriculture is associated with mech...

  7. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  8. The Traffic Light Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    Traffic lights are an important part of the transportation infrastructure, regulating traffic flow and maintaining safety when crossing busy streets. When they go awry or become nonfunctional, a great deal of havoc and danger can be present. During power outages, the street lights go out all over the affected area. It would be good to be able to…

  9. Fast Drawing of Traffic Sign Using Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Yao, Q.; Tan, B.; Huang, Y.

    2016-06-01

    Traffic sign provides road users with the specified instruction and information to enhance traffic safety. Automatic detection of traffic sign is important for navigation, autonomous driving, transportation asset management, etc. With the advance of laser and imaging sensors, Mobile Mapping System (MMS) becomes widely used in transportation agencies to map the transportation infrastructure. Although many algorithms of traffic sign detection are developed in the literature, they are still a tradeoff between the detection speed and accuracy, especially for the large-scale mobile mapping of both the rural and urban roads. This paper is motivated to efficiently survey traffic signs while mapping the road network and the roadside landscape. Inspired by the manual delineation of traffic sign, a drawing strategy is proposed to quickly approximate the boundary of traffic sign. Both the shape and color prior of the traffic sign are simultaneously involved during the drawing process. The most common speed-limit sign circle and the statistic color model of traffic sign are studied in this paper. Anchor points of traffic sign edge are located with the local maxima of color and gradient difference. Starting with the anchor points, contour of traffic sign is drawn smartly along the most significant direction of color and intensity consistency. The drawing process is also constrained by the curvature feature of the traffic sign circle. The drawing of linear growth is discarded immediately if it fails to form an arc over some steps. The Kalman filter principle is adopted to predict the temporal context of traffic sign. Based on the estimated point,we can predict and double check the traffic sign in consecutive frames.The event probability of having a traffic sign over the consecutive observations is compared with the null hypothesis of no perceptible traffic sign. The temporally salient traffic sign is then detected statistically and automatically as the rare event of having a

  10. Multimedia traffic monitoring system

    NASA Astrophysics Data System (ADS)

    Al-Sayegh, Osamah A.; Dashti, Ali E.

    2000-10-01

    Increasing congestion on roads and highways, and the problems associated with conventional traffic monitoring systems have generated an interest in new traffic surveillance systems, such as video image processing. These systems are expected to be more effective and more economical than conventional surveillance systems. In this paper, we describe the design of a traffic surveillance system, called Multimedia traffic Monitoring System. The system is based on a client/server model, with the following main modules: 1) video image capture module (VICM), 2) video image processing module (VIPM), and 3) database module (DBM). The VICM is used to capture the live feed from a digital camera. Depending on the mode of operation, VICM either: 1) sends the video images directly to the VIPM (on the same processing node), or 2) compresses the video images and sends them to the VIPM and/or the DBM on separate processing node(s). The main contribution of this paper is the design of a traffic monitoring system that uses image processing (VIPM) to estimate traffic flow. In the current implementation, VIPM estimates the number of vehicles per kilometer, while using 9 image sequences (at a rate of 4 frames per second). The VIPM algorithm generates a virtual grid and superimposes it on a part of the traffic scene. Motion and vehicle detection operators are carried out within each cell in the grid. Vehicle count is concluded based on the nine images of a sequence. The system is tested against a manual count of more than 40 image sequences (total of more than 365 traffic images) of various traffic situations. The results show that the system is able to determine the traffic flow with a precision of 1.5 vehicles per kilometer.

  11. Traffic flow wide-area surveillance system definition

    SciTech Connect

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.; Abston, R.A.; Carnal, C.L.; Moynihan, P.I.

    1994-11-01

    Traffic Flow Wide-Area Surveillance (TFWAS) is a system for assessing the state of traffic flow over a wide area for enhanced traffic control and improved traffic management and planning. The primary purpose of a TFWAS system is to provide a detailed traffic flow description and context description to sophisticated traffic management and control systems being developed or envisioned for the future. A successful TFWAS system must possess the attributes of safety, reconfigurability, reliability, and expandability. The primary safety premise of TFWAS is to ensure that no action or failure of the TFWAS system or its components can result in risk of injury to humans. A wide variety of communication techniques is available for use with TFWAS systems. These communication techniques can be broken down into two categories, landlines and wireless. Currently used and possible future traffic sensing technologies have been examined. Important criteria for selecting TFWAS sensors include sensor capabilities, costs, operational constraints, sensor compatibility with the infrastructure, and extent. TFWAS is a concept that can take advantage of the strengths of different traffic sensing technologies, can readily adapt to newly developed technologies, and can grow with the development of new traffic control strategies. By developing innovative algorithms that will take information from a variety of sensor types and develop descriptions of traffic flows over a wide area, a more comprehensive understanding of the traffic state can be provided to the control system to perform the most reasonable control actions over the entire wide area. The capability of characterizing the state of traffic over an entire region should revolutionize developments in traffic control strategies.

  12. Outer Space Traffic Safety Standards

    NASA Astrophysics Data System (ADS)

    Larsen, Paul B.

    2013-09-01

    Management of traffic in outer space is a major safety problem. Traffic is increasing. Most satellites are navigable but they have to co-exist with space debris which is not navigable. We need minimum safety rules for outer space traffic. We have the possible beginnings of international safety standards in the form of national space object tracking; Global Navigation Satellite Systems (GNSS) standardization through ICAO and the International Committee on GNSS (ICG); the IADC space debris guidelines; and the proposed Code of Conduct. However, safety could be improved by standards for such activities as licensing launches of satellites into outer space; standards for accident investigation and search and rescue: operational safety zones around space objects such as the International Space Station. This paper describes legal authority for minimum safety standards. It considers safety standards established by private agreements among commercial operators. Finally it examines a number of options for an international forum to establish safety standards, including self-regulation, COPUOS, ICAO, ITU, a space code of conduct, and a new space organization.

  13. Fine-Tuning ADAS Algorithm Parameters for Optimizing Traffic ...

    EPA Pesticide Factsheets

    With the development of the Connected Vehicle technology that facilitates wirelessly communication among vehicles and road-side infrastructure, the Advanced Driver Assistance Systems (ADAS) can be adopted as an effective tool for accelerating traffic safety and mobility optimization at various highway facilities. To this end, the traffic management centers identify the optimal ADAS algorithm parameter set that enables the maximum improvement of the traffic safety and mobility performance, and broadcast the optimal parameter set wirelessly to individual ADAS-equipped vehicles. After adopting the optimal parameter set, the ADAS-equipped drivers become active agents in the traffic stream that work collectively and consistently to prevent traffic conflicts, lower the intensity of traffic disturbances, and suppress the development of traffic oscillations into heavy traffic jams. Successful implementation of this objective requires the analysis capability of capturing the impact of the ADAS on driving behaviors, and measuring traffic safety and mobility performance under the influence of the ADAS. To address this challenge, this research proposes a synthetic methodology that incorporates the ADAS-affected driving behavior modeling and state-of-the-art microscopic traffic flow modeling into a virtually simulated environment. Building on such an environment, the optimal ADAS algorithm parameter set is identified through an optimization programming framework to enable th

  14. The Nature of Peer-to-Peer Traffic

    NASA Astrophysics Data System (ADS)

    Gomes, João V. P.; Inácio, Pedro R. M.; Freire, Mário M.; Pereira, Manuela; Monteiro, Paulo P.

    The massive adoption of Peer-to-Peer (P2P) applications brings new challenges for network management. The increase of the bandwidth usage, the shift of the Internet habits of home users and the easiness to share and provide contents is changing the traffic characteristics, and breaking strong assumptions in which network design is based. As a response to concerns from network administrators and Internet Service Providers, traffic management is now a requirement instead of an option, making the traffic classification functionality into an essential administration tool. However, the evasive nature of most P2P applications renders the classification of their traffic a difficult task to achieve even through Deep Packet Inspections of the data units, mostly due to the application of encryption and randomizationmechanisms. In order to meet the demand for new and accurate methods for traffic classification in the dark, it is necessary to study and fully understand the deep nature of P2P traffic. In this chapter, the characteristics of this type of traffic are discussed and explained, and recent studies about traffic characterisation are introduced and analysed from the perspective that may enable their application for traffic classification.

  15. Air Traffic Network Project

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The high level requirement of the Air Traffic Network (ATN) project is to provide a mechanism for evaluating the impact of router scheduling modifications on a networks efficiency, without implementing the modifications in the live network.

  16. Examining Road Traffic Mortality Status in China: A Simulation Study

    PubMed Central

    Schwebel, David C.; Li, Li; Hu, Guoqing

    2016-01-01

    Background Data from the Chinese police service suggest substantial reductions in road traffic injuries since 2002, but critics have questioned the accuracy of those data, especially considering conflicting data reported by the health department. Methods To address the gap between police and health department data and to determine which may be more accurate, we conducted a simulation study based on the modified Smeed equation, which delineates a non-linear relation between road traffic mortality and the level of motorization in a country or region. Our goal was to simulate trends in road traffic mortality in China and compare performances in road traffic safety management between China and 13 other countries. Results Chinese police data indicate a peak in road traffic mortalities in 2002 and a significant and a gradual decrease in population-based road traffic mortality since 2002. Health department data show the road traffic mortality peaked in 2012. In addition, police data suggest China’s road traffic mortality peaked at a much lower motorization level (0.061 motor vehicles per person) in 2002, followed by a reduction in mortality to a level comparable to that of developed countries. Simulation results based on health department data suggest high road traffic mortality, with a mortality peak in 2012 at a moderate motorization level (0.174 motor vehicles per person). Comparisons to the other 13 countries suggest the health data from China may be more valid than the police data. Conclusion Our simulation data indicate China is still at a stage of high road traffic mortality, as suggested by health data, rather than a stage of low road traffic mortality, as suggested by police data. More efforts are needed to integrate safety into road design, improve road traffic management, improve data quality, and alter unsafe behaviors of pedestrians, drivers and passengers in China. PMID:27071008

  17. Traffic congestion forecasting model for the INFORM System. Final report

    SciTech Connect

    Azarm, A.; Mughabghab, S.; Stock, D.

    1995-05-01

    This report describes a computerized traffic forecasting model, developed by Brookhaven National Laboratory (BNL) for a portion of the Long Island INFORM Traffic Corridor. The model has gone through a testing phase, and currently is able to make accurate traffic predictions up to one hour forward in time. The model will eventually take on-line traffic data from the INFORM system roadway sensors and make projections as to future traffic patterns, thus allowing operators at the New York State Department of Transportation (D.O.T.) INFORM Traffic Management Center to more optimally manage traffic. It can also form the basis of a travel information system. The BNL computer model developed for this project is called ATOP for Advanced Traffic Occupancy Prediction. The various modules of the ATOP computer code are currently written in Fortran and run on PC computers (pentium machine) faster than real time for the section of the INFORM corridor under study. The following summarizes the various routines currently contained in the ATOP code: Statistical forecasting of traffic flow and occupancy using historical data for similar days and time (long term knowledge), and the recent information from the past hour (short term knowledge). Estimation of the empirical relationships between traffic flow and occupancy using long and short term information. Mechanistic interpolation using macroscopic traffic models and based on the traffic flow and occupancy forecasted (item-1), and the empirical relationships (item-2) for the specific highway configuration at the time of simulation (construction, lane closure, etc.). Statistical routine for detection and classification of anomalies and their impact on the highway capacity which are fed back to previous items.

  18. 23 CFR 511.309 - Provisions for traffic and travel conditions reporting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Provisions for traffic and travel conditions reporting... Management Information Program § 511.309 Provisions for traffic and travel conditions reporting. (a) Minimum requirements for traffic and travel conditions made available by real-time information programs are:...

  19. 23 CFR 511.309 - Provisions for traffic and travel conditions reporting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 23 Highways 1 2014-04-01 2014-04-01 false Provisions for traffic and travel conditions reporting... Management Information Program § 511.309 Provisions for traffic and travel conditions reporting. (a) Minimum requirements for traffic and travel conditions made available by real-time information programs are:...

  20. 23 CFR 511.309 - Provisions for traffic and travel conditions reporting.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Provisions for traffic and travel conditions reporting... Management Information Program § 511.309 Provisions for traffic and travel conditions reporting. (a) Minimum requirements for traffic and travel conditions made available by real-time information programs are:...

  1. 23 CFR 511.309 - Provisions for traffic and travel conditions reporting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Provisions for traffic and travel conditions reporting... Management Information Program § 511.309 Provisions for traffic and travel conditions reporting. (a) Minimum requirements for traffic and travel conditions made available by real-time information programs are:...

  2. Vehicle traffic control. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-03-01

    The bibliography contains citations concerning the design, development, and application of vehicle traffic control equipment and systems. Among the systems described are automatic vehicle identifiers for traffic management, urban traffic control systems for the reduction of indirect sources of air pollution, and other automatic vehicle location devices and systems. (Contains 250 citations and includes a subject term index and title list.)

  3. A Novel P2P traffic Prediction Algorithm Based on Hybrid Model

    NASA Astrophysics Data System (ADS)

    Zhi-jie, Han; Ru-chuan, Wang; Xiao-yang, Duan

    The increasing P2P network traffic on the Internet has leaded to the problem of network congestion. In the consequence of the diversification of the P2P traffic and protocol, research on the management of P2P traffic has had many problems needed to resolve. P2P traffic Prediction is kernel problem in the P2P traffic management. Based on the P2P traffic characters, this thesis present a P2P traffic model, gived a traffic prediction algorithm bases on wavelet-analysis, and proved the accuracy of the algorithm. Simulation has experiment figures that the algorithm a high prediction precision and superior real-time performance.

  4. Traffic improvement and transportation pollution control in Xiamen

    SciTech Connect

    Dongxing Yuan; Zilin, Wu

    1996-12-31

    in this paper, the urban traffic improvement and transportation control in Xiamen are highlighted. Xiamen is a port city and an economical special zone of China. As the economy grows, the transportation is developing dramatically and becoming the key for further economic development. The air quality is threatened by the rapid growth of the vehicles in the city. The most urgent task in improving urban traffic is to establish a sound traffic system. The municipal government takes great effort to improve the traffic condition, as well as to reduce green house gases and protect air environment. Some management and technical measures are carried out. Those management measures are mainly as follows: (1) systematic planning of the city arrangement and city functional division, and integrated planning of the urban roads system, (2) putting great emphasis on tail gas monitoring and management, and (3) establishing optimized utilization of motor vehicles. Those included in the main technical measures are (1) making the roads clear, (2) enlarging traffic capacity, and (3) developing the public transport. The most urgent task in improving urban traffic is to establish a sound traffic system. The city municipal government and Transportation Management Bureau plan to make a series of reforms to improve the urban traffic condition, such as building high quality road around the city, reducing the number of one way roads and replacing gasoline buses with electric buses. An optimized traffic system of Xiamen, taking public transport as the main means, is the key to meet the needs of both traffic improvement and urban transportation pollution control.

  5. An Agent-Based Model for Analyzing Control Policies and the Dynamic Service-Time Performance of a Capacity-Constrained Air Traffic Management Facility

    NASA Technical Reports Server (NTRS)

    Conway, Sheila R.

    2006-01-01

    Simple agent-based models may be useful for investigating air traffic control strategies as a precursory screening for more costly, higher fidelity simulation. Of concern is the ability of the models to capture the essence of the system and provide insight into system behavior in a timely manner and without breaking the bank. The method is put to the test with the development of a model to address situations where capacity is overburdened and potential for propagation of the resultant delay though later flights is possible via flight dependencies. The resultant model includes primitive representations of principal air traffic system attributes, namely system capacity, demand, airline schedules and strategy, and aircraft capability. It affords a venue to explore their interdependence in a time-dependent, dynamic system simulation. The scope of the research question and the carefully-chosen modeling fidelity did allow for the development of an agent-based model in short order. The model predicted non-linear behavior given certain initial conditions and system control strategies. Additionally, a combination of the model and dimensionless techniques borrowed from fluid systems was demonstrated that can predict the system s dynamic behavior across a wide range of parametric settings.

  6. Physics of Traffic

    NASA Astrophysics Data System (ADS)

    Schreckenberg, Michael

    2002-03-01

    In the past decade the investigation of the complex behaviour of traffic dynamics became an active field of (interdisciplinary) research. On the one hand this is due to a fastly growing availability of 'experimental' data from measurements with various kinds of sensors, on the other hand due to an enormous improvement of the modelling techniques from statistical physics. This has led to the identification of several new phases of traffic flow and the characterization of the corresponding phase transitions between them. Nowadays many of the occurring dynamical phenomena are understood quite well although a complete understanding, especially of the interrelation between the models on the different scales (micro-, meso-, macroscopic), is still missing. Whereas earlier attempts tried to describe traffic flow in a hydrodynamical formulation the current microscopic models are able to take into not only the physically correct motion of single cars but also certain aspects of the driver's behaviour. It turns out that the simple car following theories cannot explain the complex structures found, e.g., in synchronized traffic, a new state found only recently. Here a more detailed analysis is necessary which goes far beyond the pure modelling of the motion of the cars in analogy to granular media (grains of sand, pills, corn, etc.). The detailed knowledge of traffic dynamics not of purely scientific interest but also absolutely necessary for practical applications. With the help of online data from measurements of flows and speeds it is possible to construct a complete picture of the actual traffic state with real time simulations. As a very efficient model ansatz cellular automata have been shown to be a reasonable compromise between simulation speed and descripiton accuracy. Beyond the reproduction of the actual state a reliable traffic forecast should be possible although the driver's reaction on the forecast still remains unclear.

  7. A Wavelet Analysis Approach for Categorizing Air Traffic Behavior

    NASA Technical Reports Server (NTRS)

    Drew, Michael; Sheth, Kapil

    2015-01-01

    In this paper two frequency domain techniques are applied to air traffic analysis. The Continuous Wavelet Transform (CWT), like the Fourier Transform, is shown to identify changes in historical traffic patterns caused by Traffic Management Initiatives (TMIs) and weather with the added benefit of detecting when in time those changes take place. Next, with the expectation that it could detect anomalies in the network and indicate the extent to which they affect traffic flows, the Spectral Graph Wavelet Transform (SGWT) is applied to a center based graph model of air traffic. When applied to simulations based on historical flight plans, it identified the traffic flows between centers that have the greatest impact on either neighboring flows, or flows between centers many centers away. Like the CWT, however, it can be difficult to interpret SGWT results and relate them to simulations where major TMIs are implemented, and more research may be warranted in this area. These frequency analysis techniques can detect off-nominal air traffic behavior, but due to the nature of air traffic time series data, so far they prove difficult to apply in a way that provides significant insight or specific identification of traffic patterns.

  8. Data link air traffic control and flight deck environments: Experiment in flight crew performance

    NASA Technical Reports Server (NTRS)

    Lozito, Sandy; Mcgann, Alison; Corker, Kevin

    1993-01-01

    This report describes an experiment undertaken in a full mission simulation environment to investigate the performance impact of, and human/system response to, data-linked Air Traffic Control (ATC) and automated flight deck operations. Subjects were twenty pilots (ten crews) from a major United States air carrier. Crews flew the Advanced Concepts Flight Simulator (ACFS), a generic 'glass cockpit' simulator at NASA Ames. The method of data link used was similar to the data link implementation plans for a next-generation aircraft, and included the capability to review ATC messages and directly enter ATC clearance information into the aircraft systems. Each crew flew experimental scenarios, in which data reflecting communication timing, errors and clarifications, and procedures were collected. Results for errors and clarifications revealed an interaction between communication modality (voice v. data link) and communication type (air/ground v. intracrew). Results also revealed that voice crews initiated ATC contact significantly more than data link crews. It was also found that data link crews performed significantly more extraneous activities during the communication task than voice crews. Descriptive data from the use of the review menu indicate the pilot-not-flying accessing the review menu most often, and also suggest diffulty in accessing the target message within the review menu structure. The overall impact of communication modality upon air/ground communication and crew procedures is discussed.

  9. A refined and dynamic cellular automaton model for pedestrian-vehicle mixed traffic flow

    NASA Astrophysics Data System (ADS)

    Liu, Mianfang; Xiong, Shengwu

    2016-12-01

    Mixed traffic flow sharing the “same lane” and having no discipline on road is a common phenomenon in the developing countries. For example, motorized vehicles (m-vehicles) and nonmotorized vehicles (nm-vehicles) may share the m-vehicle lane or nm-vehicle lane and pedestrians may share the nm-vehicle lane. Simulating pedestrian-vehicle mixed traffic flow consisting of three kinds of traffic objects: m-vehicles, nm-vehicles and pedestrians, can be a challenge because there are some erratic drivers or pedestrians who fail to follow the lane disciplines. In the paper, we investigate various moving and interactive behavior associated with mixed traffic flow, such as lateral drift including illegal lane-changing and transverse crossing different lanes, overtaking and forward movement, and propose some new moving and interactive rules for pedestrian-vehicle mixed traffic flow based on a refined and dynamic cellular automaton (CA) model. Simulation results indicate that the proposed model can be used to investigate the traffic flow characteristic in a mixed traffic flow system and corresponding complicated traffic problems, such as, the moving characteristics of different traffic objects, interaction phenomenon between different traffic objects, traffic jam, traffic conflict, etc., which are consistent with the actual mixed traffic system. Therefore, the proposed model provides a solid foundation for the management, planning and evacuation of the mixed traffic flow.

  10. Traffic camera system development

    NASA Astrophysics Data System (ADS)

    Hori, Toshi

    1997-04-01

    The intelligent transportation system has generated a strong need for the development of intelligent camera systems to meet the requirements of sophisticated applications, such as electronic toll collection (ETC), traffic violation detection and automatic parking lot control. In order to achieve the highest levels of accuracy in detection, these cameras must have high speed electronic shutters, high resolution, high frame rate, and communication capabilities. A progressive scan interline transfer CCD camera, with its high speed electronic shutter and resolution capabilities, provides the basic functions to meet the requirements of a traffic camera system. Unlike most industrial video imaging applications, traffic cameras must deal with harsh environmental conditions and an extremely wide range of light. Optical character recognition is a critical function of a modern traffic camera system, with detection and accuracy heavily dependent on the camera function. In order to operate under demanding conditions, communication and functional optimization is implemented to control cameras from a roadside computer. The camera operates with a shutter speed faster than 1/2000 sec. to capture highway traffic both day and night. Consequently camera gain, pedestal level, shutter speed and gamma functions are controlled by a look-up table containing various parameters based on environmental conditions, particularly lighting. Lighting conditions are studied carefully, to focus only on the critical license plate surface. A unique light sensor permits accurate reading under a variety of conditions, such as a sunny day, evening, twilight, storms, etc. These camera systems are being deployed successfully in major ETC projects throughout the world.

  11. Occupant traffic estimation through structural vibration sensing

    NASA Astrophysics Data System (ADS)

    Pan, Shijia; Mirshekari, Mostafa; Zhang, Pei; Noh, Hae Young

    2016-04-01

    The number of people passing through different indoor areas is useful in various smart structure applications, including occupancy-based building energy/space management, marketing research, security, etc. Existing approaches to estimate occupant traffic include vision-, sound-, and radio-based (mobile) sensing methods, which have placement limitations (e.g., requirement of line-of-sight, quiet environment, carrying a device all the time). Such limitations make these direct sensing approaches difficult to deploy and maintain. An indirect approach using geophones to measure floor vibration induced by footsteps can be utilized. However, the main challenge lies in distinguishing multiple simultaneous walkers by developing features that can effectively represent the number of mixed signals and characterize the selected features under different traffic conditions. This paper presents a method to monitor multiple persons. Once the vibration signals are obtained, features are extracted to describe the overlapping vibration signals induced by multiple footsteps, which are used for occupancy traffic estimation. In particular, we focus on analysis of the efficiency and limitations of the four selected key features when used for estimating various traffic conditions. We characterize these features with signals collected from controlled impulse load tests as well as from multiple people walking through a real-world sensing area. In our experiments, the system achieves the mean estimation error of +/-0.2 people for different occupant traffic conditions (from one to four) using k-nearest neighbor classifier.

  12. Drilling and thermal gradient measurements at US Marine Corps Air Ground Combat Center, Twentynine Palms, California. Final report, October 1, 1983-March 31, 1984

    SciTech Connect

    Trexler, D.T.; Flynn, T.; Ghusn, G. Jr.

    1984-01-01

    Seven temperature gradient holes were drilled at the Marine Corps Air Ground Combat Center, Twentynine Palms, California, as part of a cooperative research and development program, jointly funded by the Navy and Department of Energy. The purpose of this program was to assess geothermal resources at selected Department of Defense installations. Drill site selection was based on geophysical anomalies delineated by combined gravity, ground magnetic and aeromagnetic surveys. Temperature gradients ranged from 1.3/sup 0/C/100 m (1/sup 0/F/100 ft.) in hole No. 1 to 15.3/sup 0/C/100 m (8.3/sup 0/F/100 ft.) in temperature gradient hole No. 6. Large, positive geothermal gradients in temperature gradient holes 5 and 6, combined with respective bottom hole temperatures of 51.6/sup 0/C (125/sup 0/F) and 67/sup 0/C (153/sup 0/F), indicate that an extensive, moderate-temperature geothermal resource is located on the MCAGCC. The geothermal reservoir appears to be situated in old, unconsolidated alluvial material and is structurally bounded on the east by the Mesquite Lake fault and on the west by the Surprise Spring fault. If measured temperature gradients continue to increase at the observed rate, temperatures in excess of 80/sup 0/C (178/sup 0/F) can be expected at a depth of 2000 feet.

  13. Emergent traffic jams

    SciTech Connect

    Nagel, K.; Paczuski, M. |

    1995-04-01

    We study a single-lane traffic model that is based on human driving behavior. The outflow from a traffic jam self-organizes to a critical state of maximum throughput. Small perturbations of the outflow far downstream create emergent traffic jams with a power law distribution {ital P}({ital t}){similar_to}{ital t}{sup {minus}3/2} of lifetimes {ital t}. On varying the vehicle density in a closed system, this critical state separates lamellar and jammed regimes and exhibits 1/{ital f} noise in the power spectrum. Using random walk arguments, in conjunction with a cascade equation, we develop a phenomenological theory that predicts the critical exponents for this transition and explains the self-organizing behavior. These predictions are consistent with all of our numerical results.

  14. Generalized Deterministic Traffic Rules

    NASA Astrophysics Data System (ADS)

    Fuks, Henryk; Boccara, Nino

    We study a family of deterministic models for highway traffic flow which generalize cellular automaton rule 184. This family is parameterized by the speed limit m and another parameter k that represents a "degree of aggressiveness" in driving, strictly related to the distance between two consecutive cars. We compare two driving strategies with identical maximum throughput: "conservative" driving with high speed limit and "aggressive" driving with low speed limit. Those two strategies are evaluated in terms of accident probability. We also discuss fundamental diagrams of generalized traffic rules and examine limitations of maximum achievable throughput. Possible modifications of the model are considered.

  15. 2013 Traffic Safety Culture Index

    MedlinePlus

    ... death in the United States. 2013 Traffic Safety Culture Index January 2014 607 14th Street, NW, Suite ... org | 202-638-5944 Title 2013 Traffic Safety Culture Index (January 2014) About the Sponsor AAA Foundation ...

  16. Alcohol and Traffic Safety.

    ERIC Educational Resources Information Center

    Dickman, Frances Baker, Ed.

    1988-01-01

    Seven papers discuss current issues and applied social research concerning alcohol traffic safety. Prevention, policy input, methodology, planning strategies, anti-drinking/driving programs, social-programmatic orientations of Mothers Against Drunk Driving, Kansas Driving Under the Influence Law, New Jersey Driving While Impaired Programs,…

  17. The Classroom Traffic Jam

    ERIC Educational Resources Information Center

    Edwards, Arthur W.

    1977-01-01

    The importance of energy conservation is developed in this simulation. Children draw an automobile and then are asked to drive it through the classroom roadways. When a traffic jam results, students offer ways to eliminate it. The importance of mass transportation and car pools is stressed by the teacher. (MA)

  18. CATS-based Air Traffic Controller Agents

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.

    2002-01-01

    This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human

  19. Traffic Safety Facts, 2001: Pedestrians.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1991-2001; (2) pedestrians killed and injured, by age group, 2001; (3) non-occupant traffic fatalities, 1991-2001; (4) pedestrian fatalities, by time of day and day of week,…

  20. Pedestrians. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. traffic accidents involving pedestrians. Data tables include: (1) trends in pedestrian and total traffic fatalities, 1990-2000; (2) pedestrians killed and injured, by age group, 2000; (3) non-occupant traffic fatalities, 1990-2000; (4) pedestrian fatalities, by time of day and day of week,…

  1. Traffic Safety Facts, 2001: Pedalcylists.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on traffic accidents involving U.S. bicyclists. Data include: (1) trends in pedalcyclist and total traffic fatalities, 1991-2001; (2) non-occupant traffic fatalities, 1991-2001; (3) pedalcyclists killed and injured, and fatality and injury rates, by age and sex, 2000 [2001 population data by age group…

  2. Pedalcylists. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on traffic accidents involving U.S. bicyclists. Data include: (1) trends in pedalcyclist and total traffic fatalities, 1990-2000; (2) non-occupant traffic fatalities, 1990-2000; (3) pedalcyclists killed and injured, and fatality and injury rates, by age and sex, 2000; and (4) pedalcyclist traffic…

  3. Face Sheet/Core Disbond Growth in Honeycomb Sandwich Panels Subjected to Ground-Air-Ground Pressurization and In-Plane Loading

    NASA Technical Reports Server (NTRS)

    Chen, Zhi M.; Krueger, Ronald; Rinker, Martin

    2015-01-01

    Typical damage modes in light honeycomb sandwich structures include face sheet/core disbonding and core fracture, both of which can pose a threat to the structural integrity of a component. These damage modes are of particular interest to aviation certification authorities since several in-service occurrences, such as rudder structural failure and other control surface malfunctions, have been attributed to face sheet/core disbonding. Extensive studies have shown that face sheet/core disbonding and core fracture can lead to damage propagation caused by internal pressure changes in the core. The increasing use of composite sandwich construction in aircraft applications makes it vitally important to understand the effect of ground-air-ground (GAG) cycles and conditions such as maneuver and gust loads on face sheet/core disbonding. The objective of the present study was to use a fracture mechanics based approach developed earlier to evaluate the loading at the disbond front caused by ground-air-ground pressurization and in-plane loading. A honeycomb sandwich panel containing a circular disbond at one face sheet/core interface was modeled with three-dimensional (3D) solid finite elements. The disbond was modeled as a discrete discontinuity and the strain energy release rate along the disbond front was computed using the Virtual Crack Closure Technique (VCCT). Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed. The commercial finite element analysis software, Abaqus/Standard, was used for the analyses. The recursive pressure-deformation coupling problem was solved by representing the entrapped air in the honeycomb cells as filled cavities in Abaqus/Standard. The results show that disbond size, face sheet thickness and core thickness are important parameters that determine crack tip loading at the disbond front. Further, the pressure

  4. A SPATIOTEMPORAL APPROACH FOR HIGH RESOLUTION TRAFFIC FLOW IMPUTATION

    SciTech Connect

    Han, Lee; Chin, Shih-Miao; Hwang, Ho-Ling

    2016-01-01

    Along with the rapid development of Intelligent Transportation Systems (ITS), traffic data collection technologies have been evolving dramatically. The emergence of innovative data collection technologies such as Remote Traffic Microwave Sensor (RTMS), Bluetooth sensor, GPS-based Floating Car method, automated license plate recognition (ALPR) (1), etc., creates an explosion of traffic data, which brings transportation engineering into the new era of Big Data. However, despite the advance of technologies, the missing data issue is still inevitable and has posed great challenges for research such as traffic forecasting, real-time incident detection and management, dynamic route guidance, and massive evacuation optimization, because the degree of success of these endeavors depends on the timely availability of relatively complete and reasonably accurate traffic data. A thorough literature review suggests most current imputation models, if not all, focus largely on the temporal nature of the traffic data and fail to consider the fact that traffic stream characteristics at a certain location are closely related to those at neighboring locations and utilize these correlations for data imputation. To this end, this paper presents a Kriging based spatiotemporal data imputation approach that is able to fully utilize the spatiotemporal information underlying in traffic data. Imputation performance of the proposed approach was tested using simulated scenarios and achieved stable imputation accuracy. Moreover, the proposed Kriging imputation model is more flexible compared to current models.

  5. Advanced traffic control strategies for intelligent vehicle highway systems

    NASA Astrophysics Data System (ADS)

    Gartner, Nathan H.; Stamatiadis, C.; Tarnoff, P. J.

    1995-01-01

    This paper discusses traffic signal control strategies that are suitable for advanced traffic management within IVHS (Intelligent Vehicle Highway Systems). The strategies consist of a multi-level design for the real-time, traffic-adaptive control of the urban signal network system. Each control level has different response characteristics, with the more advanced levels incorporating in a nested fashion the capabilities of the lower levels. A principal goal of the new multi-level design is to invoke a selected control strategy when it can provide the greatest benefit.

  6. Generalized force model of traffic dynamics

    NASA Astrophysics Data System (ADS)

    Helbing, Dirk; Tilch, Benno

    1998-07-01

    Floating car data of car-following behavior in cities were compared to existing microsimulation models, after their parameters had been calibrated to the experimental data. With these parameter values, additional simulations have been carried out, e.g., of a moving car which approaches a stopped car. It turned out that, in order to manage such kinds of situations without producing accidents, improved traffic models are needed. Good results were obtained with the proposed generalized force model.

  7. Computer-Aided Air-Traffic Control In The Terminal Area

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    1995-01-01

    Developmental computer-aided system for automated management and control of arrival traffic at large airport includes three integrated subsystems. One subsystem, called Traffic Management Advisor, another subsystem, called Descent Advisor, and third subsystem, called Final Approach Spacing Tool. Data base that includes current wind measurements and mathematical models of performances of types of aircraft contributes to effective operation of system.

  8. Road Traffic Noise

    NASA Astrophysics Data System (ADS)

    Beckenbauer, Thomas

    Road traffic is the most interfering noise source in developed countries. According to a publication of the European Union (EU) at the end of the twentieth century [1], about 40% of the population in 15 EU member states is exposed to road traffic noise at mean levels exceeding 55 dB(A). Nearly 80 million people, 20% of the population, are exposed to levels exceeding 65 dB(A) during daytime and more than 30% of the population is exposed to levels exceeding 55 dB(A) during night time. Such high noise levels cause health risks and social disorders (aggressiveness, protest, and helplessness), interference of communication and disturbance of sleep; the long- and short-term consequences cause adverse cardiovascular effects, detrimental hormonal responses (stress hormones), and possible disturbance of the human metabolism (nutrition) and the immune system. Even performance at work and school could be impaired.

  9. Situational Leadership in Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Arvidsson, Marcus; Johansson, Curt R.; Ek, Asa; Akselsson, Roland

    2007-01-01

    In high-risk environments such as air traffic control, leadership on different levels plays a certain role in establishing, promoting, and maintaining a good safety culture. The current study aimed to investigate how leadership styles, leadership style adaptability, and over and under task leadership behavior differed across situations, operative conditions, leadership structures, and working tasks in an air traffic control setting. Study locations were two air traffic control centers in Sweden with different operational conditions and leadership structures, and an administrative air traffic management unit. Leadership was measured with a questionnaire based on Leader Effectiveness and Adaptability Description (LEAD; Blanchard, Zigarmi & Zigarmi, 2003; Hersey & Blanchard, 1988). The results showed that the situation had strong impact on the leadership in which the leadership behavior was more relationship oriented in Success and Group situations than in Hardship and Individual situations. The leadership adaptability was further superior in Success and Individual situations compared with Hardship and Group situations. Operational conditions, leadership structures and working tasks were, on the other hand, not associated with leadership behavior.

  10. Identifying MMORPG Bots: A Traffic Analysis Approach

    NASA Astrophysics Data System (ADS)

    Chen, Kuan-Ta; Jiang, Jhih-Wei; Huang, Polly; Chu, Hao-Hua; Lei, Chin-Laung; Chen, Wen-Chin

    2008-12-01

    Massively multiplayer online role playing games (MMORPGs) have become extremely popular among network gamers. Despite their success, one of MMORPG's greatest challenges is the increasing use of game bots, that is, autoplaying game clients. The use of game bots is considered unsportsmanlike and is therefore forbidden. To keep games in order, game police, played by actual human players, often patrol game zones and question suspicious players. This practice, however, is labor-intensive and ineffective. To address this problem, we analyze the traffic generated by human players versus game bots and propose general solutions to identify game bots. Taking Ragnarok Online as our subject, we study the traffic generated by human players and game bots. We find that their traffic is distinguishable by 1) the regularity in the release time of client commands, 2) the trend and magnitude of traffic burstiness in multiple time scales, and 3) the sensitivity to different network conditions. Based on these findings, we propose four strategies and two ensemble schemes to identify bots. Finally, we discuss the robustness of the proposed methods against countermeasures of bot developers, and consider a number of possible ways to manage the increasingly serious bot problem.

  11. Physics of Traffic Flow

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2015-03-01

    The Texas A&M Transportation Institute estimated that traffic congestion cost the United States 121 billion in 2011 (the latest data available). The cost is due to wasted time and fuel. In addition to accidents and road construction, factors contributing to congestion include large demand, instability of high-density free flow and selfish behavior of drivers, which produces self-organized traffic bottlenecks. Extensive data collected on instrumented highways in various countries have led to a better understanding of traffic dynamics. From these measurements, Boris Kerner and colleagues developed a new theory called three-phase theory. They identified three major phases of flow observed in the data: free flow, synchronous flow and wide moving jams. The intermediate phase is called synchronous because vehicles in different lanes tend to have similar velocities. This congested phase, characterized by lower velocities yet modestly high throughput, frequently occurs near on-ramps and lane reductions. At present there are only two widely used methods of congestion mitigation: ramp metering and the display of current travel-time information to drivers. To find more effective methods to reduce congestion, researchers perform large-scale simulations using models based on the new theories. An algorithm has been proposed to realize Wardrop equilibria with real-time route information. Such equilibria have equal travel time on alternative routes between a given origin and destination. An active area of current research is the dynamics of connected vehicles, which communicate wirelessly with other vehicles and the surrounding infrastructure. These systems show great promise for improving traffic flow and safety.

  12. Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information.

    PubMed

    Bao, Xu; Li, Haijian; Qin, Lingqiao; Xu, Dongwei; Ran, Bin; Rong, Jian

    2016-10-27

    To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads.

  13. Sensor Location Problem Optimization for Traffic Network with Different Spatial Distributions of Traffic Information

    PubMed Central

    Bao, Xu; Li, Haijian; Qin, Lingqiao; Xu, Dongwei; Ran, Bin; Rong, Jian

    2016-01-01

    To obtain adequate traffic information, the density of traffic sensors should be sufficiently high to cover the entire transportation network. However, deploying sensors densely over the entire network may not be realistic for practical applications due to the budgetary constraints of traffic management agencies. This paper describes several possible spatial distributions of traffic information credibility and proposes corresponding different sensor information credibility functions to describe these spatial distribution properties. A maximum benefit model and its simplified model are proposed to solve the traffic sensor location problem. The relationships between the benefit and the number of sensors are formulated with different sensor information credibility functions. Next, expanding models and algorithms in analytic results are performed. For each case, the maximum benefit, the optimal number and spacing of sensors are obtained and the analytic formulations of the optimal sensor locations are derived as well. Finally, a numerical example is proposed to verify the validity and availability of the proposed models for solving a network sensor location problem. The results show that the optimal number of sensors of segments with different model parameters in an entire freeway network can be calculated. Besides, it can also be concluded that the optimal sensor spacing is independent of end restrictions but dependent on the values of model parameters that represent the physical conditions of sensors and roads. PMID:27801794

  14. Traffic Games: Modeling Freeway Traffic with Game Theory

    PubMed Central

    Cortés-Berrueco, Luis E.; Gershenson, Carlos; Stephens, Christopher R.

    2016-01-01

    We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers’ interactions. PMID:27855176

  15. Traffic Games: Modeling Freeway Traffic with Game Theory.

    PubMed

    Cortés-Berrueco, Luis E; Gershenson, Carlos; Stephens, Christopher R

    2016-01-01

    We apply game theory to a vehicular traffic model to study the effect of driver strategies on traffic flow. The resulting model inherits the realistic dynamics achieved by a two-lane traffic model and aims to incorporate phenomena caused by driver-driver interactions. To achieve this goal, a game-theoretic description of driver interaction was developed. This game-theoretic formalization allows one to model different lane-changing behaviors and to keep track of mobility performance. We simulate the evolution of cooperation, traffic flow, and mobility performance for different modeled behaviors. The analysis of these results indicates a mobility optimization process achieved by drivers' interactions.

  16. Congestion transition in air traffic networks.

    PubMed

    Monechi, Bernardo; Servedio, Vito D P; Loreto, Vittorio

    2015-01-01

    Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.

  17. Congestion Transition in Air Traffic Networks

    PubMed Central

    Monechi, Bernardo; Servedio, Vito D. P.; Loreto, Vittorio

    2015-01-01

    Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios. PMID:25993476

  18. Parallel Vehicular Traffic Simulation using Reverse Computation-based Optimistic Execution

    SciTech Connect

    Yoginath, Srikanth B; Perumalla, Kalyan S

    2008-01-01

    Vehicular traffic simulations are useful in applications such as emergency management and homeland security planning tools. High speed of traffic simulations translates directly to speed of response and level of resilience in those applications. Here, a parallel traffic simulation approach is presented that is aimed at reducing the time for simulating emergency vehicular traffic scenarios. Three unique aspects of this effort are: (1) exploration of optimistic simulation applied to vehicular traffic simulation (2) addressing reverse computation challenges specific to optimistic vehicular traffic simulation (3) achieving absolute (as opposed to self-relative) speedup with a sequential speed equal to that of a fast, de facto standard sequential simulator for emergency traffic. The design and development of the parallel simulation system is presented, along with a performance study that demonstrates excellent sequential performance as well as parallel performance.

  19. Kalman filter approach to traffic modeling and prediction

    NASA Astrophysics Data System (ADS)

    Grindey, Gregory J.; Amin, S. M.; Rodin, Ervin Y.; Garcia-Ortiz, Asdrubal

    1998-01-01

    The objective of our work has been to develop and integrate prediction, control and optimization modules for use in highway traffic management. This is accomplished through the use of the Semantic Control paradigm, implementing a hybrid prediction/routing/control system, to model both macro-level as well a micro level. This paper addresses the design and operation of a Kalman filter that processes traffic sensor data in order to model and predict highway traffic volume. This data was given in the form of hourly traffic flow, and has been fit using a cubic spline method to allow observations at various time intervals. THe filter is augmented via the Method of Sage and Husa to identify the parameters of the system noise on-line, and to determine the dynamics of the traffic process iteratively to aid in the prediction of the future traffic. The results show a good ability to predict traffic flow at the sensors for several time periods in the future, as well as some noise rejection capabilities.

  20. Near real-time traffic routing

    NASA Technical Reports Server (NTRS)

    Yang, Chaowei (Inventor); Cao, Ying (Inventor); Xie, Jibo (Inventor); Zhou, Bin (Inventor)

    2012-01-01

    A near real-time physical transportation network routing system comprising: a traffic simulation computing grid and a dynamic traffic routing service computing grid. The traffic simulator produces traffic network travel time predictions for a physical transportation network using a traffic simulation model and common input data. The physical transportation network is divided into a multiple sections. Each section has a primary zone and a buffer zone. The traffic simulation computing grid includes multiple of traffic simulation computing nodes. The common input data includes static network characteristics, an origin-destination data table, dynamic traffic information data and historical traffic data. The dynamic traffic routing service computing grid includes multiple dynamic traffic routing computing nodes and generates traffic route(s) using the traffic network travel time predictions.

  1. Economical Video Monitoring of Traffic

    NASA Technical Reports Server (NTRS)

    Houser, B. C.; Paine, G.; Rubenstein, L. D.; Parham, O. Bruce, Jr.; Graves, W.; Bradley, C.

    1986-01-01

    Data compression allows video signals to be transmitted economically on telephone circuits. Telephone lines transmit television signals to remote traffic-control center. Lines also carry command signals from center to TV camera and compressor at highway site. Video system with television cameras positioned at critical points on highways allows traffic controllers to determine visually, almost immediately, exact cause of traffic-flow disruption; e.g., accidents, breakdowns, or spills, almost immediately. Controllers can then dispatch appropriate emergency services and alert motorists to minimize traffic backups.

  2. Understanding the T2 traffic in CMS during Run-1

    NASA Astrophysics Data System (ADS)

    T, Wildish

    2015-12-01

    In the run-up to Run-1 CMS was operating its facilities according to the MONARC model, where data-transfers were strictly hierarchical in nature. Direct transfers between Tier-2 nodes was excluded, being perceived as operationally intensive and risky in an era where the network was expected to be a major source of errors. By the end of Run-1 wide-area networks were more capable and stable than originally anticipated. The original data-placement model was relaxed, and traffic was allowed between Tier-2 nodes. Tier-2 to Tier-2 traffic in 2012 already exceeded the amount of Tier-2 to Tier-1 traffic, so it clearly has the potential to become important in the future. Moreover, while Tier-2 to Tier-1 traffic is mostly upload of Monte Carlo data, the Tier-2 to Tier-2 traffic represents data moved in direct response to requests from the physics analysis community. As such, problems or delays there are more likely to have a direct impact on the user community. Tier-2 to Tier-2 traffic may also traverse parts of the WAN that are at the 'edge' of our network, with limited network capacity or reliability compared to, say, the Tier-0 to Tier-1 traffic which goes the over LHCOPN network. CMS is looking to exploit technologies that allow us to interact with the network fabric so that it can manage our traffic better for us, this we hope to achieve before the end of Run-2. Tier-2 to Tier-2 traffic would be the most interesting use-case for such traffic management, precisely because it is close to the users' analysis and far from the 'core' network infrastructure. As such, a better understanding of our Tier-2 to Tier-2 traffic is important. Knowing the characteristics of our data-flows can help us place our data more intelligently. Knowing how widely the data moves can help us anticipate the requirements for network capacity, and inform the dynamic data placement algorithms we expect to have in place for Run-2. This paper presents an analysis of the CMS Tier-2 traffic during Run 1.

  3. An intelligent traffic controller

    SciTech Connect

    Kagolanu, K.; Fink, R.; Smartt, H.; Powell, R.; Larsen, E.

    1995-12-01

    A controller with advanced control logic can significantly improve traffic flows at intersections. In this vein, this paper explores fuzzy rules and algorithms to improve the intersection operation by rationalizing phase changes and green times. The fuzzy logic for control is enhanced by the exploration of neural networks for families of membership functions and for ideal cost functions. The concepts of fuzzy logic control are carried forth into the controller architecture. Finally, the architecture and the modules are discussed. In essence, the control logic and architecture of an intelligent controller are explored.

  4. Multicast traffic grooming in flexible optical WDM networks

    NASA Astrophysics Data System (ADS)

    Patel, Ankitkumar N.; Ji, Philip N.; Jue, Jason P.; Wang, Ting

    2012-12-01

    In Metropolitan Area Networks (MANs), point-to-multipoint applications, such as IPTV, video-on-demand, distance learning, and content distribution, can be efficiently supported through light-tree-based multicastcommunications instead of lightpath-based unicast-communications. The application of multicasting for such traffic is justified by its inherent benefits of reduced control and management overhead and elimination of redundant resource provisioning. Supporting such multicast traffic in Flexible optical WDM (FWDM) networks that can provision light-trees using optimum amount of spectrum within flexible channel spacing leads to higher wavelength and spectral efficiencies compared to the conventional ITU-T fixed grid networks. However, in spite of such flexibility, the residual channel capacity of stranded channels may not be utilized if the network does not offer channels with arbitrary line rates. Additionally, the spectrum allocated to guard bands used to isolate finer granularity channels remains unutilized. These limitations can be addressed by using traffic grooming in which low-rate multicast connections are aggregated and switched over high capacity light-trees. In this paper, we address the multicast traffic grooming problem in FWDM networks, and propose a novel auxiliary graph-based algorithm for the first time. The performance of multicast traffic grooming is evaluated in terms of spectral, cost, and energy efficiencies compared to lightpath-based transparent FWDM networks, lightpathbased traffic grooming-capable FWDM networks, multicast-enabled transparent FWDM networks, and multicast traffic grooming-capable fixed grid networks. Simulation results demonstrate that multicast traffic grooming in FWDM networks not only improves spectral efficiency, but also cost, and energy efficiencies compared to other multicast traffic provisioning approaches of FWDM and fixed grid networks.

  5. Complexity Analysis of Traffic in Corridors-in-the-Sky

    NASA Technical Reports Server (NTRS)

    Xue, Min; Zelinski, Shannon Jean

    2010-01-01

    The corridors-in-the-sky concept imitates the highway system in ground transportation. The benefit expected from a corridor relies on its capability of handling high density traffic with negligible controller workload, the acceptance of extra fuel or distance, and the complexity reduction in underlying sectors. This work evaluates a selected corridor from these perspectives through simulations. To examine traffic inside the corridor, a corridor traffic simulation tool that can resolve conflicts is developed using C language. Prescribed conflict resolution maneuvers mimic corridor users behaviors and conflict resolution counts measure complexity. Different lane options and operational policies are proposed to examine their impacts on complexity. Fuel consumption is calculated and compared for corridor traffic. On the other hand, to investigate the complexity of non-corridor traffic in underlying sectors, the existing Airspace Concept Evaluation System tool is utilized along with the Automated Airspace Concept tool. The number of conflict resolutions is examined and treated as the complexity measurement. The results show heavy traffic can be managed with low complexity for a historical traffic schedule simulated with appropriate operational policies and lane options. For instance, with 608 flights and peak aircraft count of 100, only 84 actions need to be taken in a 24-hour period to resolve the conflicts for an 8-lane corridor. Compared with the fuel consumptions with great circle trajectories, the simulation of corridor traffic shows that the total extra fuel for corridor flights is 26,373 gallons, or 2.76%, which is 0.38% less than flying filed flight plans. Without taking climb and descent portions of corridor traffic, the complexity of underlying sectors is reduced by 17.71%. However the climb and descent portions will eliminate the reduction and the overall complexity of sectors is actually increased by 9.14%.

  6. Large scale traffic simulations

    SciTech Connect

    Nagel, K.; Barrett, C.L. |; Rickert, M. |

    1997-04-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computational speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated {open_quotes}looping{close_quotes} between the microsimulation and the simulated planning of individual person`s behavior is necessary). As a rough number, a real-time simulation of an area such as Los Angeles (ca. 1 million travellers) will need a computational speed of much higher than 1 million {open_quotes}particle{close_quotes} (= vehicle) updates per second. This paper reviews how this problem is approached in different projects and how these approaches are dependent both on the specific questions and on the prospective user community. The approaches reach from highly parallel and vectorizable, single-bit implementations on parallel supercomputers for Statistical Physics questions, via more realistic implementations on coupled workstations, to more complicated driving dynamics implemented again on parallel supercomputers. 45 refs., 9 figs., 1 tab.

  7. TRAFFIC AND TRANSPORTATION. (BUSINESS TECHNOLOGY).

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Community Colleges, Raleigh.

    THE PREEMPLOYMENT, 6-QUARTER CURRICULUM IS FOR USE IN TECHNICAL INSTITUTES AND COMMUNITY COLLEGES. ITS PURPOSE IS TO PROVIDE TRAINING IN NEW TECHNIQUES AND UNDERSTANDING OF THE LATEST STATE AND FEDERAL REGULATIONS APPLICABLE TO TRAFFIC AND TRANSPORTATION. GRADUATES OF THIS CURRICULUM MAY SEEK CAREER OPPORTUNITIES AS TRAFFIC REPRESENTATIVES, CLAIMS…

  8. Probabilistic description of traffic flow

    NASA Astrophysics Data System (ADS)

    Mahnke, R.; Kaupužs, J.; Lubashevsky, I.

    2005-03-01

    A stochastic description of traffic flow, called probabilistic traffic flow theory, is developed. The general master equation is applied to relatively simple models to describe the formation and dissolution of traffic congestions. Our approach is mainly based on spatially homogeneous systems like periodically closed circular rings without on- and off-ramps. We consider a stochastic one-step process of growth or shrinkage of a car cluster (jam). As generalization we discuss the coexistence of several car clusters of different sizes. The basic problem is to find a physically motivated ansatz for the transition rates of the attachment and detachment of individual cars to a car cluster consistent with the empirical observations in real traffic. The emphasis is put on the analogy with first-order phase transitions and nucleation phenomena in physical systems like supersaturated vapour. The results are summarized in the flux-density relation, the so-called fundamental diagram of traffic flow, and compared with empirical data. Different regimes of traffic flow are discussed: free flow, congested mode as stop-and-go regime, and heavy viscous traffic. The traffic breakdown is studied based on the master equation as well as the Fokker-Planck approximation to calculate mean first passage times or escape rates. Generalizations are developed to allow for on-ramp effects. The calculated flux-density relation and characteristic breakdown times coincide with empirical data measured on highways. Finally, a brief summary of the stochastic cellular automata approach is given.

  9. Traffic Calming: A Social Issue

    ERIC Educational Resources Information Center

    Crouse, David W.

    2004-01-01

    Substantial urban growth fueled by a strong economy often results in heavy traffic thus making streets less hospitable. Traffic calming is one response to the pervasiveness of the automobile. The issues concern built environments and involve multiple actors reflecting different interests. The issues are rarely technical and involve combinations of…

  10. Basic model for traffic interweave

    NASA Astrophysics Data System (ADS)

    Huang, Ding-wei

    2015-09-01

    We propose a three-parameter traffic model. The system consists of a loop with two junctions. The three parameters control the inflow, the outflow (from the junctions,) and the interweave (in the loop.) The dynamics is deterministic. The boundary conditions are stochastic. We present preliminary results for a complete phase diagram and all possible phase transitions. We observe four distinct traffic phases: free flow, congestion, bottleneck, and gridlock. The proposed model is able to present economically a clear perspective to these four different phases. Free flow and congestion are caused by the traffic conditions in the junctions. Both bottleneck and gridlock are caused by the traffic interweave in the loop. Instead of directly related to conventional congestion, gridlock can be taken as an extreme limit of bottleneck. This model can be useful to clarify the characteristics of traffic phases. This model can also be extended for practical applications.

  11. Photonics approach to traffic signs

    NASA Astrophysics Data System (ADS)

    Litwin, Dariusz; Galas, Jacek; CzyŻewski, Adam; Rymsza, Barbara; Kornalewski, Leszek; Kryszczyński, Tadeusz; Mikucki, Jerzy; Wikliński, Piotr; Daszkiewicz, Marek; Malasek, Jacek

    2016-12-01

    The automotive industry has been always a driving force for all economies. Despite of its beneficial meaning to every society it brings also many issues including wide area of road safety. The latter has been enforced by the increasing number of cars and the dynamic development of the traffic as a whole. Road signs and traffic lights are crucial in context of good traffic arrangement and its fluency. Traffic designers are used to treat horizontal road signs independently of vertical signs. However, modern light sources and growing flexibility in shaping optical systems create opportunity to design more advanced and smart solutions. In this paper we present an innovative, multidisciplinary approach that consists in tight interdependence of different traffic signals. We describe new optical systems together with their influence on the perception of the road user. The analysis includes maintenance and visibility in different weather conditions. A special attention has been focused on intersections of complex geometry.

  12. A flight management algorithm and guidance for fuel-conservative descents in a time-based metered air traffic environment: Development and flight test results

    NASA Technical Reports Server (NTRS)

    Knox, C. E.

    1984-01-01

    A simple airborne flight management descent algorithm designed to define a flight profile subject to the constraints of using idle thrust, a clean airplane configuration (landing gear up, flaps zero, and speed brakes retracted), and fixed-time end conditions was developed and flight tested in the NASA TSRV B-737 research airplane. The research test flights, conducted in the Denver ARTCC automated time-based metering LFM/PD ATC environment, demonstrated that time guidance and control in the cockpit was acceptable to the pilots and ATC controllers and resulted in arrival of the airplane over the metering fix with standard deviations in airspeed error of 6.5 knots, in altitude error of 23.7 m (77.8 ft), and in arrival time accuracy of 12 sec. These accuracies indicated a good representation of airplane performance and wind modeling. Fuel savings will be obtained on a fleet-wide basis through a reduction of the time error dispersions at the metering fix and on a single-airplane basis by presenting the pilot with guidance for a fuel-efficient descent.

  13. Concept definition of traffic flow wide-area surveillance

    SciTech Connect

    Allgood, G.O.; Ferrell, R.K.; Kercel, S.W.

    1994-07-01

    Traffic management can be thought of as a stochastic queuing process where the serving time at one of its control points is dynamically linked to the global traffic pattern, which is, in turn, dynamically linked to the control point. For this closed-loop system to be effective, the traffic management system must sense and interpret large spatial projections of data originating from multiple sensor suites. The intent of the Wide-Area Surveillance (WAS) Project is to build upon this concept and define the operational specifications and characteristics of a Traffic Flow Wide-Area Surveillance (TFWAS) system in terms of traffic management and control. In doing so, the functional capabilities of a TFWAS will be mapped onto an operational profile that is consistent with the Federal Highway Administration`s Intelligent Vehicle Highway System. This document provides the underlying foundation of this work by offering a concept definition for the TFWAS system. It concentrates on answering the question: ``What is the system?`` In doing so, the report develops a hierarchy of specialized definitions.

  14. Virtualized Traffic: reconstructing traffic flows from discrete spatiotemporal data.

    PubMed

    Sewall, Jason; van den Berg, Jur; Lin, Ming C; Manocha, Dinesh

    2011-01-01

    We present a novel concept, Virtualized Traffic, to reconstruct and visualize continuous traffic flows from discrete spatiotemporal data provided by traffic sensors or generated artificially to enhance a sense of immersion in a dynamic virtual world. Given the positions of each car at two recorded locations on a highway and the corresponding time instances, our approach can reconstruct the traffic flows (i.e., the dynamic motions of multiple cars over time) between the two locations along the highway for immersive visualization of virtual cities or other environments. Our algorithm is applicable to high-density traffic on highways with an arbitrary number of lanes and takes into account the geometric, kinematic, and dynamic constraints on the cars. Our method reconstructs the car motion that automatically minimizes the number of lane changes, respects safety distance to other cars, and computes the acceleration necessary to obtain a smooth traffic flow subject to the given constraints. Furthermore, our framework can process a continuous stream of input data in real time, enabling the users to view virtualized traffic events in a virtual world as they occur. We demonstrate our reconstruction technique with both synthetic and real-world input.

  15. Traffic information computing platform for big data

    SciTech Connect

    Duan, Zongtao Li, Ying Zheng, Xibin Liu, Yan Dai, Jiting Kang, Jun

    2014-10-06

    Big data environment create data conditions for improving the quality of traffic information service. The target of this article is to construct a traffic information computing platform for big data environment. Through in-depth analysis the connotation and technology characteristics of big data and traffic information service, a distributed traffic atomic information computing platform architecture is proposed. Under the big data environment, this type of traffic atomic information computing architecture helps to guarantee the traffic safety and efficient operation, more intelligent and personalized traffic information service can be used for the traffic information users.

  16. Work-related road traffic injury: a multilevel systems protocol

    PubMed Central

    Newnam, Sharon; Sheppard, Dianne M; Griffin, Mark A; McClure, Roderick J; Heller, Gillian; Sim, Malcolm R; Stevenson, Mark R

    2014-01-01

    Background Although road traffic injury is reported as the leading cause of work-related death in Australia, it is not clear, due to limitations in previous methods used, just how large a burden it is. Many organisations are unaware of the extent of work-related road traffic injury and, importantly, what can be done to reduce the burden. The proposed research will (i) estimate the prevalence of work-related road traffic injury and (ii) identify the organisational determinants associated with work-related road traffic injury. Methods and design The current study is designed to enumerate the problem and identify the individual driver-level, the supervisor-level and organisational-level factors associated with work-related road traffic injury. The multilevel systems protocol will involve a series of cross-sectional surveys administered to drivers of fleet vehicles (n=1200), supervisors of the drivers (n=1200) and senior managers (n=300) within the same organisation. Discussion The novel use of the multilevel systems protocol is critical to be able to accurately assess the specific determinants of driving safety within each context of an organisation. Results The results are expected to highlight that reducing injury in the workplace requires more than just individual compliance with safety procedures. It will also establish, for the first time, an occupational translation taskforce to ensure that the research findings are adopted into work-place practice and thereby directly contribute to reductions in work-related road traffic injury. PMID:24478230

  17. 76 FR 62148 - Information Collection Activities: Submission for the Office of Management and Budget (OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... National Highway Traffic Safety Administration Information Collection Activities: Submission for the Office of Management and Budget (OMB) Review; Request for Comment AGENCY: National Highway Traffic Safety... Information Officer (NPO 400), National Highway Traffic Safety Administration, W51-204, Department...

  18. Fluctuations in Urban Traffic Networks

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Dong; Li, Li; Zhang, Yi; Hu, Jian-Ming; Jin, Xue-Xiang

    Urban traffic network is a typical complex system, in which movements of tremendous microscopic traffic participants (pedestrians, bicyclists and vehicles) form complicated spatial and temporal dynamics. We collected flow volumes data on the time-dependent activity of a typical urban traffic network, finding that the coupling between the average flux and the fluctuation on individual links obeys a certain scaling law, with a wide variety of scaling exponents between 1/2 and 1. These scaling phenomena can explain the interaction between the nodes' internal dynamics (i.e. queuing at intersections, car-following in driving) and changes in the external (network-wide) traffic demand (i.e. the every day increase of traffic amount during peak hours and shocking caused by traffic accidents), allowing us to further understand the mechanisms governing the transportation system's collective behavior. Multiscaling and hotspot features are observed in the traffic flow data as well. But the reason why the separated internal dynamics are comparable to the external dynamics in magnitude is still unclear and needs further investigations.

  19. An Electronic Commerce Strategy for MTMC’s Guaranteed Traffic Program

    DTIC Science & Technology

    1992-10-01

    AD-A264 299 SELECTE October 1992 S MAY1 4 1993U C An Electronic Commerce Strategy for MTMC’s Guaranteed Traffic Program MT901R I N1. Augustine...NUMBERS An Electronic Commerce Strategy for MTMC’s Guaranteed Traffic Program C MDA903-85-C -0139 M DA903-90-C-0006 PE 0902198D 6. AUTHOR(S) M...239-1L 299-01 LMI Executive Summary AN ELECTRONIC COMMERCE STRATEGY FOR MTMC’S GUARANTEED TRAFFIC PROGRAM In 1979, the Military Traffic Management

  20. Temporal Patterns of Road Traffic Injuries in Iran

    PubMed Central

    Khorshidi, Ali; Ainy, Elaheh; Hashemi Nazari, Seyed Saeed; Soori, Hamid

    2016-01-01

    Background Road traffic injuries (RTIs) are the main causes of death and disability in Iran. However, very few studies about the temporal variations of RTIs have been published to date. Objectives This study was conducted to investigate the temporal pattern of RTIs in Iran in 2012. Materials and Methods All road traffic accidents (RTAs) reported to traffic police during a one-year period (March 21, 2012 through March 21, 2013) were investigated after obtaining permission from the law enforcement force of the Islamic Republic of Iran. Distributions of RTAs were obtained for season, month, week, and hour scales, and for long holidays (more than one day) and the day prior to long holidays (DPLH). The final analysis was carried out using the Poisson regression model to calculate incidence rate ratios for RTIs. All analyses were conducted using STATA 13.1 and Excel software; statistical significance was set at P < 0.05. Results A total of 452,192 RTAs were examined. The estimated rate of all accidents was 219 per 10,000 registered vehicles, or 595 per 100,000 people. About 28% of all RTAs, and more than one third of fatal RTAs, occurred during the summer months. The incidence rate for all traffic accidents on DPLH was 1.20, compared to workdays as a reference category, and it was 1.40 for fatal crashes. The rate of fatal road traffic accidents in outer cities was 3.2 times higher than in inner ones. Conclusions Our findings reveal that there are temporal variations in traffic accidents, and long holidays significantly influence accident rates. Traffic injuries have different patterns on outer/inner city roads, based on weekday and holiday status. Thus, these findings could be used to create effective initiatives aimed at traffic management. PMID:27703958

  1. Real-Time Traffic Information for Emergency Evacuations

    SciTech Connect

    Franzese, Oscar; Zhang, Li; Mahmoud, Anas M.

    2010-01-01

    There are many instances in which it is possible to plan ahead for an emergency evacuation (e.g., a chemical processing facility explosion). For those cases, if an accident were to happen, then the best evacuation plan for the prevailing network and weather conditions would be deployed. In other cases (e.g., the derailment of a train transporting hazardous materials), there may not be any previously developed plan to be implemented, and decisions must be made ad-hoc on how to proceed with an emergency evacuation. In both situations, the availability of real-time traffic information plays a critical role in the management of the evacuation operations. Due to cost constraints, only large urban areas have traffic sensor deployments that permit access to some sort of real-time traffic information; an evacuation taking place in other areas of the country would have to proceed without real-time traffic information. In order to improve operations during a vehicular emergency evacuation anywhere, a system of sensors that uses newly developed real-time traffic-information-gathering technologies to assess traffic conditions and to detect incidents on the main evacuation routes is presented in this paper. A series of tests, both in a controlled environment and in the field, were conducted to study the feasibility of such a system of traffic sensors and to assess its ability to provide real-time traffic information during an emergency evacuation. The results of these tests indicated that the prototype sensors are reliable and accurate for the type of application that is the focus of this paper.

  2. Comprehensive optimization of emergency evacuation route and departure time under traffic control.

    PubMed

    Li, Guo; Zhou, Ying; Liu, Mengqi

    2014-01-01

    With the frequent occurrence of major emergencies, emergency management gets high attention from all around the world. This paper investigates the comprehensive optimization of major emergency evacuation route and departure time, in which case the evacuation propagation mechanism is considered under traffic control. Given the practical assumptions, we first establish a comprehensive optimization model based on the simulation of evacuation route and departure time. Furthermore, we explore the reasonable description method of evacuation traffic flow propagation under traffic control, including the establishment of traffic flow propagation model and the design of the simulation module that can simulate the evacuation traffic flow. Finally, we propose a heuristic algorithm for the optimization of this comprehensive model. In case analysis, we take some areas in Beijing as the evaluation sources to verify the reliability of our model. A series of constructive suggestions for Beijing's emergency evacuation are proposed, which can be applied to the actual situation under traffic control.

  3. How long will the traffic flow time series keep efficacious to forecast the future?

    NASA Astrophysics Data System (ADS)

    Yuan, PengCheng; Lin, XuXun

    2017-02-01

    This paper investigate how long will the historical traffic flow time series keep efficacious to forecast the future. In this frame, we collect the traffic flow time series data with different granularity at first. Then, using the modified rescaled range analysis method, we analyze the long memory property of the traffic flow time series by computing the Hurst exponent. We calculate the long-term memory cycle and test its significance. We also compare it with the maximum Lyapunov exponent method result. Our results show that both of the freeway traffic flow time series and the ground way traffic flow time series demonstrate positively correlated trend (have long-term memory property), both of their memory cycle are about 30 h. We think this study is useful for the short-term or long-term traffic flow prediction and management.

  4. Comprehensive Optimization of Emergency Evacuation Route and Departure Time under Traffic Control

    PubMed Central

    Zhou, Ying; Liu, Mengqi

    2014-01-01

    With the frequent occurrence of major emergencies, emergency management gets high attention from all around the world. This paper investigates the comprehensive optimization of major emergency evacuation route and departure time, in which case the evacuation propagation mechanism is considered under traffic control. Given the practical assumptions, we first establish a comprehensive optimization model based on the simulation of evacuation route and departure time. Furthermore, we explore the reasonable description method of evacuation traffic flow propagation under traffic control, including the establishment of traffic flow propagation model and the design of the simulation mudule that can simulate the evacuation traffic flow. Finally, we propose a heuristic algorithm for the optimization of this comprehensive model. In case analysis, we take some areas in Beijing as the evaluation sources to verify the reliability of our model. A series of constructive suggestions for Beijing's emergency evacuation are proposed, which can be applied to the actual situation under traffic control. PMID:24977232

  5. Design of a final approach spacing tool for TRACON air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Erzberger, Heinz; Bergeron, Hugh

    1989-01-01

    This paper describes an automation tool that assists air traffic controllers in the Terminal Radar Approach Control (TRACON) Facilities in providing safe and efficient sequencing and spacing of arrival traffic. The automation tool, referred to as the Final Approach Spacing Tool (FAST), allows the controller to interactively choose various levels of automation and advisory information ranging from predicted time errors to speed and heading advisories for controlling time error. FAST also uses a timeline to display current scheduling and sequencing information for all aircraft in the TRACON airspace. FAST combines accurate predictive algorithms and state-of-the-art mouse and graphical interface technology to present advisory information to the controller. Furthermore, FAST exchanges various types of traffic information and communicates with automation tools being developed for the Air Route Traffic Control Center. Thus it is part of an integrated traffic management system for arrival traffic at major terminal areas.

  6. [Traffic accidents: a qualitative approach from Campinas, São Paulo, Brazil].

    PubMed

    Queiroz, Marcos S; Oliveira, Patrícia C P

    2002-01-01

    This article takes an interdisciplinary qualitative approach to the problem of traffic accidents in Campinas, São Paulo, Brazil. The authors begin by analyzing the "municipalization" (i.e., decentralization to the municipal level) of transport and traffic management in Campinas based on social representations by members of the local government's technical staff. Data demonstrate a significant drop in traffic accident mortality in Campinas in the last ten years. The findings illustrate how new transport and traffic policies had several positive effects. Special attention is given to the objectives, strategies, and obstacles dealt with by local government in the "municipalization" of traffic. The paper concludes by emphasizing the need for specific public policies to revitalize urban mass transportation, including special traffic safety educational programs.

  7. Effects of mental workload on physiological and subjective responses during traffic density monitoring: A field study.

    PubMed

    Fallahi, Majid; Motamedzade, Majid; Heidarimoghadam, Rashid; Soltanian, Ali Reza; Miyake, Shinji

    2016-01-01

    This study evaluated operators' mental workload while monitoring traffic density in a city traffic control center. To determine the mental workload, physiological signals (ECG, EMG) were recorded and the NASA-Task Load Index (TLX) was administered for 16 operators. The results showed that the operators experienced a larger mental workload during high traffic density than during low traffic density. The traffic control center stressors caused changes in heart rate variability features and EMG amplitude, although the average workload score was significantly higher in HTD conditions than in LTD conditions. The findings indicated that increasing traffic congestion had a significant effect on HR, RMSSD, SDNN, LF/HF ratio, and EMG amplitude. The results suggested that when operators' workload increases, their mental fatigue and stress level increase and their mental health deteriorate. Therefore, it maybe necessary to implement an ergonomic program to manage mental health. Furthermore, by evaluating mental workload, the traffic control center director can organize the center's traffic congestion operators to sustain the appropriate mental workload and improve traffic control management.

  8. The effect of traffic tickets on road traffic crashes.

    PubMed

    Factor, Roni

    2014-03-01

    Road traffic crashes are globally a leading cause of death. The current study tests the effect of traffic tickets issued to drivers on subsequent crashes, using a unique dataset that overcomes some shortcomings of previous studies. The study takes advantage of a national longitudinal dataset at the individual level that merges Israeli census data with data on traffic tickets issued by the police and official data on involvement in road traffic crashes over seven years. The results show that the estimated probability of involvement in a subsequent fatal or severe crash was more than eleven times higher for drivers with six traffic tickets per year compared to those with one ticket per year, while controlling for various confounders. However, the majority of fatal and severe crashes involved the larger population of drivers who received up to one ticket on average per year. The current findings indicate that reducing traffic violations may contribute significantly to crash and injury reduction. In addition, mass random enforcement programs may be more effective in reducing fatal and severe crashes than targeting high-risk recidivist drivers.

  9. Relationship between Weather, Traffic and Delay Based on Empirical Methods

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Swei, Sean S. M.

    2006-01-01

    The steady rise in demand for air transportation over the years has put much emphasis on the need for sophisticated air traffic flow management (TFM) within the National Airspace System (NAS). The NAS refers to hardware, software and people, including runways, radars, networks, FAA, airlines, etc., involved in air traffic management (ATM) in the US. One of the metrics that has been used to assess the performance of NAS is the actual delays provided through FAA's Air Traffic Operations Network (OPSNET). The OPSNET delay data includes those reportable delays, i.e. delays of 15 minutes or more experienced by Instrument Flight Rule (IFR) flights, submitted by the FAA facilities. These OPSNET delays are caused by the application of TFM initiatives in response to, for instance, weather conditions, increased traffic volume, equipment outages, airline operations, and runway conditions. TFM initiatives such as, ground stops, ground delay programs, rerouting, airborne holding, and miles-in-trail restrictions, are actions which are needed to control the air traffic demand to mitigate the demand-capacity imbalance due to the reduction in capacity. Consequently, TFM initiatives result in NAS delays. Of all the causes, weather has been identified as the most important causal factor for NAS delays. Therefore, in order to accurately assess the NAS performance, it has become necessary to create a baseline for NAS performance and establish a model which characterizes the relation between weather and NAS delays.

  10. 14 CFR 25 - Traffic and Capacity Elements

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Traffic and Capacity Elements Section 25... Traffic Reporting Requirements Section 25 Traffic and Capacity Elements General Instructions. (a) All prescribed reporting for traffic and capacity elements shall conform with the data compilation standards...

  11. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic....

  12. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic....

  13. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic....

  14. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic....

  15. 36 CFR 4.13 - Obstructing traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Obstructing traffic. 4.13... VEHICLES AND TRAFFIC SAFETY § 4.13 Obstructing traffic. The following are prohibited: (a) Stopping or... interfere with the normal flow of traffic....

  16. AAA Foundation for Traffic Safety

    MedlinePlus

    ... of Top Deadly Mistakes Made by Teen Drivers -- AAA AAA: Road debris causes avoidable crashes, deaths Save the ... Analyst Associate Researcher Program Coordinator Stay Tuned New AAA Foundation for Traffic Safety website coming Fall 2017 ...

  17. Road traffic injuries: a stocktaking.

    PubMed

    Mohan, Dinesh

    2008-08-01

    Once we accept that road traffic injury control is a public health problem, and that we have an ethical responsibility to arrange for the safety of individuals, then it follows that health and medical professionals have to assume responsibility for participating in efforts to control this pandemic. Over 1.2 million people die of road traffic crashes annually. Road traffic injuries are among the second to the sixth leading causes of death in the age groups 15-60 years in all countries around the world. Control of road traffic injuries is going to require very special efforts as patterns are different in high- and lower-income countries, and while some countermeasures are applicable internationally, others will need further research and innovation. We will need to focus on the safety of pedestrians, bicyclists and motorcyclists, speed control, and prevention of driving under the influence of alcohol.

  18. Kinetic model of network traffic

    NASA Astrophysics Data System (ADS)

    Antoniou, I.; Ivanov, V. V.; Kalinovsky, Yu. L.

    2002-05-01

    We present the first results on the application of the Prigogine-Herman kinetic approach (Kinetic Theory of Vehicular Traffic, American Elsevier Publishing Company, Inc., New York, 1971) to the network traffic. We discuss the solution of the kinetic equation for homogeneous time-independent situations and for the desired speed distribution function, obtained from traffic measurements analysis. For the log-normal desired speed distribution function the solution clearly shows two modes corresponding to individual flow patterns (low-concentration mode) and to collective flow patterns (traffic jam mode). For low-concentration situations we found almost linear dependence of the information flow versus the concentration and that the higher the average speed the lower the concentration at which the optimum flow takes place. When approaching the critical concentration there are no essential differences in the flow for different desired average speeds, whereas for the individual flow regions there are dramatic differences.

  19. Real-Time Traffic Signal Control for Optimization of Traffic Jam Probability

    NASA Astrophysics Data System (ADS)

    Cui, Cheng-You; Shin, Ji-Sun; Miyazaki, Michio; Lee, Hee-Hyol

    Real-time traffic signal control is an integral part of urban traffic control system. It can control traffic signals online according to variation of traffic flow. In this paper, we propose a new method for the real-time traffic signal control system. The system uses a Cellular Automaton model and a Bayesian Network model to predict probabilistic distributions of standing vehicles, and uses a Particle Swarm Optimization method to calculate optimal traffic signals. A simulation based on real traffic data was carried out to show the effectiveness of the proposed real-time traffic signal control system CAPSOBN using a micro traffic simulator.

  20. Basic Course in Highway Traffic Records; Course Guide.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    The twelve-part course is structured on a modular basis to allow the various topical areas and units of instruction to satisfy differing training requirements of state and local agencies which vary from state to state. It is specifically designed to provide guidence to state highway safety program management personnel, traffic records…

  1. Risk factors associated with traffic violations and accident severity in China.

    PubMed

    Zhang, Guangnan; Yau, Kelvin K W; Chen, Guanghan

    2013-10-01

    With the recent economic boom in China, vehicle volume and the number of traffic accident fatalities have become the highest in the world. Meanwhile, traffic accidents have become the leading cause of death in China. Systematically analyzing road safety data from different perspectives and applying empirical methods/implementing proper measures to reduce the fatality rate will be an urgent and challenging task for China in the coming years. In this study, we analyze the traffic accident data for the period 2006-2010 in Guangdong Province, China. These data, extracted from the Traffic Management Sector-Specific Incident Case Data Report, are the only officially available and reliable source of traffic accident data (with a sample size>7000 per year). In particular, we focus on two outcome measures: traffic violations and accident severity. Human, vehicle, road and environmental risk factors are considered. First, the results establish the role of traffic violations as one of the major risks threatening road safety. An immediate implication is: if the traffic violation rate could be reduced or controlled successfully, then the rate of serious injuries and fatalities would be reduced accordingly. Second, specific risk factors associated with traffic violations and accident severity are determined. Accordingly, to reduce traffic accident incidence and fatality rates, measures such as traffic regulations and legislation-targeting different vehicle types/driver groups with respect to the various human, vehicle and environment risk factors-are needed. Such measures could include road safety programs for targeted driver groups, focused enforcement of traffic regulations and road/transport facility improvements. Data analysis results arising from this study will shed lights on the development of similar (adjusted) measures to reduce traffic violations and/or accident fatalities and injuries, and to promote road safety in other regions.

  2. Fully automated urban traffic system

    NASA Technical Reports Server (NTRS)

    Dobrotin, B. M.; Hansen, G. R.; Peng, T. K. C.; Rennels, D. A.

    1977-01-01

    The replacement of the driver with an automatic system which could perform the functions of guiding and routing a vehicle with a human's capability of responding to changing traffic demands was discussed. The problem was divided into four technological areas; guidance, routing, computing, and communications. It was determined that the latter three areas being developed independent of any need for fully automated urban traffic. A guidance system that would meet system requirements was not being developed but was technically feasible.

  3. Classification of Automated Search Traffic

    NASA Astrophysics Data System (ADS)

    Buehrer, Greg; Stokes, Jack W.; Chellapilla, Kumar; Platt, John C.

    As web search providers seek to improve both relevance and response times, they are challenged by the ever-increasing tax of automated search query traffic. Third party systems interact with search engines for a variety of reasons, such as monitoring a web site’s rank, augmenting online games, or possibly to maliciously alter click-through rates. In this paper, we investigate automated traffic (sometimes referred to as bot traffic) in the query stream of a large search engine provider. We define automated traffic as any search query not generated by a human in real time. We first provide examples of different categories of query logs generated by automated means. We then develop many different features that distinguish between queries generated by people searching for information, and those generated by automated processes. We categorize these features into two classes, either an interpretation of the physical model of human interactions, or as behavioral patterns of automated interactions. Using the these detection features, we next classify the query stream using multiple binary classifiers. In addition, a multiclass classifier is then developed to identify subclasses of both normal and automated traffic. An active learning algorithm is used to suggest which user sessions to label to improve the accuracy of the multiclass classifier, while also seeking to discover new classes of automated traffic. Performance analysis are then provided. Finally, the multiclass classifier is used to predict the subclass distribution for the search query stream.

  4. A Fast-Time Simulation Tool for Analysis of Airport Arrival Traffic

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Meyn, Larry A.; Neuman, Frank

    2004-01-01

    The basic objective of arrival sequencing in air traffic control automation is to match traffic demand and airport capacity while minimizing delays. The performance of an automated arrival scheduling system, such as the Traffic Management Advisor developed by NASA for the FAA, can be studied by a fast-time simulation that does not involve running expensive and time-consuming real-time simulations. The fast-time simulation models runway configurations, the characteristics of arrival traffic, deviations from predicted arrival times, as well as the arrival sequencing and scheduling algorithm. This report reviews the development of the fast-time simulation method used originally by NASA in the design of the sequencing and scheduling algorithm for the Traffic Management Advisor. The utility of this method of simulation is demonstrated by examining the effect on delays of altering arrival schedules at a hub airport.

  5. 76 FR 46213 - National Standards for Traffic Control Devices; the Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... statements in the MUTCD and clarify the use of engineering judgment and studies in the application of traffic.... Department of Transportation, Dockets Management Facility, 1200 New Jersey Avenue, SE., Washington, DC 20590... provide consistency in the intended use of engineering judgment and engineering studies. The Final...

  6. Traffic Management Algorithms in Wireless Sensor Networks

    DTIC Science & Technology

    2006-09-01

    pages 48–51, Los Angeles, February 2003. [4] Ian F. Akyildiz, Weilian Su, Yogesg Sankarasubramaniam, and Erdal Cayirci. A survey on sensor networks... Mehmet C. Vuran, B. Akan, and Ian F. Akyildiz. Spatio-temporal correlation: theory and applications for wireless sensor networks. Computer Networks

  7. Statistical Engineering in Air Traffic Management Research

    NASA Technical Reports Server (NTRS)

    Wilson, Sara R.

    2015-01-01

    NASA is working to develop an integrated set of advanced technologies to enable efficient arrival operations in high-density terminal airspace for the Next Generation Air Transportation System. This integrated arrival solution is being validated and verified in laboratories and transitioned to a field prototype for an operational demonstration at a major U.S. airport. Within NASA, this is a collaborative effort between Ames and Langley Research Centers involving a multi-year iterative experimentation process. Designing and analyzing a series of sequential batch computer simulations and human-in-the-loop experiments across multiple facilities and simulation environments involves a number of statistical challenges. Experiments conducted in separate laboratories typically have different limitations and constraints, and can take different approaches with respect to the fundamental principles of statistical design of experiments. This often makes it difficult to compare results from multiple experiments and incorporate findings into the next experiment in the series. A statistical engineering approach is being employed within this project to support risk-informed decision making and maximize the knowledge gained within the available resources. This presentation describes a statistical engineering case study from NASA, highlights statistical challenges, and discusses areas where existing statistical methodology is adapted and extended.

  8. Delay banking for air traffic management

    NASA Technical Reports Server (NTRS)

    Green, Steven M. (Inventor)

    2007-01-01

    A method and associated system for time delay banking for aircraft arrival time, aircraft departure time and/or en route flight position. The delay credit value for a given flight may decrease with passage of time and may be transferred to or traded with other flights having the same or a different user (airline owner or operator). The delay credit value for a given aircraft flight depends upon an initial delay credit value, which is determined by a central system and depends upon one or more other flight characteristics. Optionally, the delay credit value decreases with passage of time. Optionally, a transaction cost is assessed against a delay credit value that is used on behalf of another flight with the same user or is traded with a different user.

  9. Traffic Flow Management: Data Mining Update

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon R.

    2012-01-01

    This presentation provides an update on recent data mining efforts that have been designed to (1) identify like/similar days in the national airspace system, (2) cluster/aggregate national-level rerouting data and (3) apply machine learning techniques to predict when Ground Delay Programs are required at a weather-impacted airport

  10. Rethinking Traffic Management: Design of Optimizable Networks

    DTIC Science & Technology

    2008-06-01

    general, boldface are used to denote vectors and small letters are used to denote its components, e.g., x with xi as its i th component; capital letters...which is represen- tative of a common network structure . In the middle is a full mesh representing the core of the network with rich connectivity. On...Aggregate utility gap for the N -node, 1-destination ring. Given the structure of (3.2), it is natural to wonder if the interaction of congestion control

  11. Managing Time and Tasks.

    ERIC Educational Resources Information Center

    Handy, Alice Evans; Yucht, Alice H.

    1993-01-01

    Includes two articles that discuss time management and mail management strategies for librarians. Highlights include identifying personal work styles; planning and prioritizing; using calendars and computers; reexamining traffic patterns; delegating; and sorting and handling mail. (Contains eight references.) (LRW)

  12. The effectiveness of structured patient education for the management of musculoskeletal disorders and injuries of the extremities: a systematic review by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration

    PubMed Central

    Randhawa, Kristi; Côté, Pierre; Gross, Douglas P; Wong, Jessica J; Yu, Hainan; Sutton, Deborah; Southerst, Danielle; Varatharajan, Sharanya; Mior, Silvano; Stupar, Maja; Shearer, Heather M; Lindsay, Gail M; Jacobs, Craig; Taylor-Vaisey, Anne

    2015-01-01

    Purpose: To determine the effectiveness of structured patient education for the management of musculoskeletal disorders and injuries of the extremities. Methods: We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and the Cochrane Central Register of Controlled Trials from January 1, 1990 to March 14, 2015. Paired reviewers independently screened titles and abstracts for eligibility. The internal validity of studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) criteria. Results from studies with a low risk of bias were synthesized using the best-evidence synthesis methodology. Results: We identified two randomized trials with a low risk of bias. Our review suggests that: 1) multimodal care and corticosteroid injections lead to faster pain relief and improvement than reassurance and advice in the short-term and similar outcomes in the long-term for patients with persistent lateral epicondylitis; and 2) providing health education material alone may be less effective than multimodal care for the management of persistent patellofemoral pain syndrome. Conclusion: Our systematic search of the literature demonstrates that little is known about the effectiveness of structured patient education for the management of musculoskeletal disorders and injuries of the extremities. Two studies suggest that when used alone, structured patient education may be less effective than other interventions used to manage persistent lateral epicondylitis and persistent patellofemoral syndrome. PMID:26816413

  13. Factors associated with road traffic injuries in Tanzania

    PubMed Central

    Boniface, Respicious; Museru, Lawrence; Kiloloma, Othman; Munthali, Victoria

    2016-01-01

    Introduction Injuries represent a significant cause of morbidity and mortality worldwide and road traffic crashes accounts for a significant proportion of these injuries. Tanzania is among the countries with high rates of road traffic crashes. The aim of this study was to determine the pattern, associated factors and management of road traffic injury patients in Tanzania. Methods A cross-sectional study of patients involved in motor traffic crashes and attended in six public hospitals of Tanzania mainland between April 2014 and September 2014. Results A total of 4675 road traffic injury patients were seen in studied hospitals, 76.6% were males. Majority (70.2%) were between 18 - 45 years age group. Motorcycles were the leading cause of road traffic crashes (53.4%), and drivers (38.3%) accounted for majority of victims. Fractures accounted for 34.1%, and injuries were severe in 2.2% as determined by the Kampala trauma score II (KTS II). Majorities 57.4% were admitted and 2.2% died at the casualty. Factors associated with mortality were; using police vehicles to hospital (P = 0.000), receiving medical attention within 2 to 10 hours after injury (P = 0.000), 18 - 45 years age group (P = 0.019), not using helmet (P = 0.007), severe injuries (P = 0.000) and sustaining multiple injury (P = 0.000). Conclusion Road traffic Injuries in Tanzania are an important public health problem, predominantly in adult males, mostly due to motorcycle crashes. It is therefore important to reinforce preventive measures and pre-hospital emergency service is urgently needed. PMID:27217872

  14. Modeling the Environmental Impact of Air Traffic Operations

    NASA Technical Reports Server (NTRS)

    Chen, Neil

    2011-01-01

    There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.

  15. Speed limit and ramp meter control for traffic flow networks

    NASA Astrophysics Data System (ADS)

    Goatin, Paola; Göttlich, Simone; Kolb, Oliver

    2016-07-01

    The control of traffic flow can be related to different applications. In this work, a method to manage variable speed limits combined with coordinated ramp metering within the framework of the Lighthill-Whitham-Richards (LWR) network model is introduced. Following a 'first-discretize-then-optimize' approach, the first order optimality system is derived and the switch of speeds at certain fixed points in time is explained, together with the boundary control for the ramp metering. Sequential quadratic programming methods are used to solve the control problem numerically. For application purposes, experimental setups are presented wherein variable speed limits are used as a traffic guidance system to avoid traffic jams on highway interchanges and on-ramps.

  16. A new cellular automata model of traffic flow with negative exponential weighted look-ahead potential

    NASA Astrophysics Data System (ADS)

    Ma, Xiao; Zheng, Wei-Fan; Jiang, Bao-Shan; Zhang, Ji-Ye

    2016-10-01

    With the development of traffic systems, some issues such as traffic jams become more and more serious. Efficient traffic flow theory is needed to guide the overall controlling, organizing and management of traffic systems. On the basis of the cellular automata model and the traffic flow model with look-ahead potential, a new cellular automata traffic flow model with negative exponential weighted look-ahead potential is presented in this paper. By introducing the negative exponential weighting coefficient into the look-ahead potential and endowing the potential of vehicles closer to the driver with a greater coefficient, the modeling process is more suitable for the driver’s random decision-making process which is based on the traffic environment that the driver is facing. The fundamental diagrams for different weighting parameters are obtained by using numerical simulations which show that the negative exponential weighting coefficient has an obvious effect on high density traffic flux. The complex high density non-linear traffic behavior is also reproduced by numerical simulations. Project supported by the National Natural Science Foundation of China (Grant Nos. 11572264, 11172247, 11402214, and 61373009).

  17. Synchronized flow in oversaturated city traffic.

    PubMed

    Kerner, Boris S; Klenov, Sergey L; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

    2013-11-01

    Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. E 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

  18. Percolation properties in a traffic model

    NASA Astrophysics Data System (ADS)

    Wang, Feilong; Li, Daqing; Xu, Xiaoyun; Wu, Ruoqian; Havlin, Shlomo

    2015-11-01

    As a dynamical complex system, traffic is characterized by a transition from free flow to congestions, which is mostly studied in highways. However, despite its importance in developing congestion mitigation strategies, the understanding of this common traffic phenomenon in a city scale is still missing. An open question is how the traffic in the network collapses from a global efficient traffic to isolated local flows in small clusters, i.e. the question of traffic percolation. Here we study the traffic percolation properties on a lattice by simulation of an agent-based model for traffic. A critical traffic volume in this model distinguishes the free state from the congested state of traffic. Our results show that the threshold of traffic percolation decreases with increasing traffic volume and reaches a minimum value at the critical traffic volume. We show that this minimal threshold is the result of longest spatial correlation between traffic flows at the critical traffic volume. These findings may help to develop congestion mitigation strategies in a network view.

  19. Current state of traffic pollution in Bangladesh and metropolitan Dhaka

    SciTech Connect

    Karim, Masud; Matsui, Hiroshi; Ohno, Takashi; Hoque, S.

    1997-12-31

    Limited resources, invested for the development of transport facilities, such as infrastructure and vehicles, coupled with the rapid rise in transport demand, existence of a huge number of non-motorized vehicles on roads, lack of application of adequate and proper traffic management schemes are producing severe transport problems in almost all the urban areas of Bangladesh. Worsening situation of traffic congestion in the streets and sufferings of the inhabitants from vehicle emissions demand extensive research in this field. However, no detailed study concerning traffic congestion and pollution problems for urban areas of Bangladesh has yet been done. Therefore, it has become increasingly important to examine the present state of the problem. This research is a preliminary evaluation of the current situation of traffic pollution problem in Bangladesh. The daily total emissions of NO{sub x}, HC, CO, PM, and SO{sub x} are estimated using the daily fuel consumption and total traffic flows in Dhaka city. Estimated daily emissions are 42, 39, 314, 14, and 42 t/d for NO{sub x}, HC, CO, PM, and SO{sub x}, respectively. The emissions estimated using two different methods revealed good correlation. Daily average concentration of NO{sub x} (NO{sub 2}, NO) were measured at 30 street locations in Dhaka city during September and November, 1996. The results showed extremely high concentrations of NO{sub 2} and NO in these locations.

  20. Cellular automata for traffic simulations

    NASA Astrophysics Data System (ADS)

    Wolf, Dietrich E.

    1999-02-01

    Traffic phenomena such as the transition from free to congested flow, lane inversion and platoon formation can be accurately reproduced using cellular automata. Being computationally extremely efficient, they simulate large traffic systems many times faster than real time so that predictions become feasible. A riview of recent results is given. The presence of metastable states at the jamming transition is discussed in detail. A simple new cellular automation is introduced, in which the interaction between cars is Galilei-invariant. It is shown that this type of interaction accounts for metastable states in a very natural way.

  1. An Evaluation Methodology for Traffic Awareness Displays

    NASA Technical Reports Server (NTRS)

    DeMaio, Joe; Dearing, Munro

    2004-01-01

    An evaluation methodology for traffic awareness displays for helicopters and other vertical/short takeoff aircraft was developed. Pilots of vertical/short takeoff aircraft wil1 require more traffic information than would pilots of conventional aircraft to avoid both other vertical/short takeoff traffic and conventional traffic. The BF Goodrich Skywatch traffic advisory display was used as a candidate display to develop a procedure for evaluating the usefulness of such displays. Four high-time helicopter pilots participated in a 16-hour flight evaluation. They flew a closed circuit in the San Francisco Bay Area. In one-half of the flights the evaluation pilot had the traffic advisory display as an aid in detecting and locating traffic. In the other half of the flights the traffic advisory display was not available to the evaluation pilot. Data examined include measures of traffic advisory display performance and pilot performance in detecting traffic, as well as subjective workload and situation awareness data. The traffic advisory system did not help the pilots to detect more traffic. The importance of detection to traffic awareness is discussed.

  2. Smart Microgrid Energy Management Controls for Improved Energy Efficiency and Renewables Integration at DoD Installations

    DTIC Science & Technology

    2013-04-01

    Device JCI: Johnson Conrols, Inc. LAN : Local Area Network MCAGCC: Marine Corps Air Ground Combat Center MCS: Microgrid Control System Multilin...distribution losses. Microgrids are envisioned as local power networks that utilize distributed energy resources (DER) and manage the local energy...Platforms (supervisory controller, the HMI, the BEM, and certified network communications) hardware and software tailored for the Twentynine Palms

  3. Traffic sharing algorithms for hybrid mobile networks

    NASA Technical Reports Server (NTRS)

    Arcand, S.; Murthy, K. M. S.; Hafez, R.

    1995-01-01

    In a hybrid (terrestrial + satellite) mobile personal communications networks environment, a large size satellite footprint (supercell) overlays on a large number of smaller size, contiguous terrestrial cells. We assume that the users have either a terrestrial only single mode terminal (SMT) or a terrestrial/satellite dual mode terminal (DMT) and the ratio of DMT to the total terminals is defined gamma. It is assumed that the call assignments to and handovers between terrestrial cells and satellite supercells take place in a dynamic fashion when necessary. The objectives of this paper are twofold, (1) to propose and define a class of traffic sharing algorithms to manage terrestrial and satellite network resources efficiently by handling call handovers dynamically, and (2) to analyze and evaluate the algorithms by maximizing the traffic load handling capability (defined in erl/cell) over a wide range of terminal ratios (gamma) given an acceptable range of blocking probabilities. Two of the algorithms (G & S) in the proposed class perform extremely well for a wide range of gamma.

  4. Comparison of road traffic emission models in Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Borge, Rafael; de Miguel, Isabel; de la Paz, David; Lumbreras, Julio; Pérez, Javier; Rodríguez, Encarnación

    2012-12-01

    Many cities in Europe have difficulties to meet the air quality standards set by the European legislation, most particularly the annual mean Limit Value for NO2. Road transport is often the main source of air pollution in urban areas and therefore, there is an increasing need to estimate current and future traffic emissions as accurately as possible. As a consequence, a number of specific emission models and emission factors databases have been developed recently. They present important methodological differences and may result in largely diverging emission figures and thus may lead to alternative policy recommendations. This study compares two approaches to estimate road traffic emissions in Madrid (Spain): the COmputer Programme to calculate Emissions from Road Transport (COPERT4 v.8.1) and the Handbook Emission Factors for Road Transport (HBEFA v.3.1), representative of the 'average-speed' and 'traffic situation' model types respectively. The input information (e.g. fleet composition, vehicle kilometres travelled, traffic intensity, road type, etc.) was provided by the traffic model developed by the Madrid City Council along with observations from field campaigns. Hourly emissions were computed for nearly 15 000 road segments distributed in 9 management areas covering the Madrid city and surroundings. Total annual NOX emissions predicted by HBEFA were a 21% higher than those of COPERT. The discrepancies for NO2 were lower (13%) since resulting average NO2/NOX ratios are lower for HBEFA. The larger differences are related to diesel vehicle emissions under "stop & go" traffic conditions, very common in distributor/secondary roads of the Madrid metropolitan area.In order to understand the representativeness of these results, the resulting emissions were integrated in an urban scale inventory used to drive mesoscale air quality simulations with the Community Multiscale Air Quality (CMAQ) modelling system (1 km2 resolution). Modelled NO2 concentrations were compared

  5. Analysis of traffic congestion induced by the work zone

    NASA Astrophysics Data System (ADS)

    Fei, L.; Zhu, H. B.; Han, X. L.

    2016-05-01

    Based on the cellular automata model, a meticulous two-lane cellular automata model is proposed, in which the driving behavior difference and the difference of vehicles' accelerations between the moving state and the starting state are taken into account. Furthermore the vehicles' motion is refined by using the small cell of one meter long. Then accompanied by coming up with a traffic management measure, a two-lane highway traffic model containing a work zone is presented, in which the road is divided into normal area, merging area and work zone. The vehicles in different areas move forward according to different lane changing rules and position updating rules. After simulation it is found that when the density is small the cluster length in front of the work zone increases with the decrease of the merging probability. Then the suitable merging length and the appropriate speed limit value are recommended. The simulation result in the form of the speed-flow diagram is in good agreement with the empirical data. It indicates that the presented model is efficient and can partially reflect the real traffic. The results may be meaningful for traffic optimization and road construction management.

  6. Hazard based models for freeway traffic incident duration.

    PubMed

    Tavassoli Hojati, Ahmad; Ferreira, Luis; Washington, Simon; Charles, Phil

    2013-03-01

    Assessing and prioritising cost-effective strategies to mitigate the impacts of traffic incidents and accidents on non-recurrent congestion on major roads represents a significant challenge for road network managers. This research examines the influence of numerous factors associated with incidents of various types on their duration. It presents a comprehensive traffic incident data mining and analysis by developing an incident duration model based on twelve months of incident data obtained from the Australian freeway network. Parametric accelerated failure time (AFT) survival models of incident duration were developed, including log-logistic, lognormal, and Weibul-considering both fixed and random parameters, as well as a Weibull model with gamma heterogeneity. The Weibull AFT models with random parameters were appropriate for modelling incident duration arising from crashes and hazards. A Weibull model with gamma heterogeneity was most suitable for modelling incident duration of stationary vehicles. Significant variables affecting incident duration include characteristics of the incidents (severity, type, towing requirements, etc.), and location, time of day, and traffic characteristics of the incident. Moreover, the findings reveal no significant effects of infrastructure and weather on incident duration. A significant and unique contribution of this paper is that the durations of each type of incident are uniquely different and respond to different factors. The results of this study are useful for traffic incident management agencies to implement strategies to reduce incident duration, leading to reduced congestion, secondary incidents, and the associated human and economic losses.

  7. Air Traffic Control Decision Support Tools for Noise Mitigation

    NASA Technical Reports Server (NTRS)

    Tobias, Leonard

    2001-01-01

    NASA has initiated a new five year program this year, the Quiet Aircraft Technology (QAT) Program, a program which will investigate airframe and engine system noise reduction. QAT will also address community noise impact. As part of this community noise impact component, NASA will investigate air traffic management (ATM) challenges in reducing noise. In particular, controller advisory automation aids will be developed to aid the air traffic controller in addressing noise concerns as he/she manages traffic in busy terminal areas. NASA has developed controller automation tools to address capacity concerns and the QAT strategy for ATM Low Noise Operations is to build upon this tool set to create added advisories for noise mitigation. The tools developed for capacity will be briefly reviewed, followed by the QAT plans to address ATM noise concerns. A major NASA goal in global civil aviation is to triple the aviation system throughput in all-weather conditions while maintaining safety. A centerpiece of this activity is the Center/TRACON Automation System (CTAS), an evolving suite of air traffic controller decision support tools (DSTs) to enhance capacity of arrivals and departures in both the enroute center and the TRACON. Two of these DSTs, the Traffic Management Advisor (TMA) and the passive Final approach Spacing Tool (pFAST), are in daily use at the Fort Worth Center and the Dallas/Fort Worth (DFW) TRACON, respectively, where capacity gains of 5-13% have been reported in recent NASA evaluations. Under the Federal Aviation Administration's (FAA) Free Flight Phase One Program, TMA and pFAST are each being implemented at six to eight additional sites. In addition, other DSTs are being developed by NASA under the umbrella of CTAS. This means that new software will be built upon CTAS, and the paradigm of real-time simulation evaluation followed by field site development and evaluation will be the pathway for the new tools. Additional information is included in the

  8. Deterministic models for traffic jams

    NASA Astrophysics Data System (ADS)

    Nagel, Kai; Herrmann, Hans J.

    1993-10-01

    We study several deterministic one-dimensional traffic models. For integer positions and velocities we find the typical high and low density phases separated by a simple transition. If positions and velocities are continuous variables the model shows self-organized critically driven by the slowest car.

  9. Overview. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. motor vehicle and traffic safety. Data include: (1) motor vehicle occupants and non-occupants killed and injured, 1990-2000; (2) persons killed and injured, and fatality and injury rates, 1990-2000; (3) restraint use rates for passenger car occupants in fatal crashes, 1990 and 2000; (4)…

  10. Traffic Safety Facts, 2001. Overview.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on U.S. motor vehicle and traffic safety. Data include: (1) motor vehicle occupants and non-occupants killed and injured, 1991-2001; (2) persons killed and injured, and fatality and injury rates, 1991-2001; (3) restraint use rates for passenger car occupants in fatal crashes, 1991 and 2001; (4)…

  11. Traffic Safety Facts, 2001: Children.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on the incidence of U.S. motor vehicle-related accidents and fatalities involving children. Data include: (1) total traffic fatalities among children 0-14 years old, by age group, 1991-2001; (2) total pedestrian fatalities among children 0-14 years old, by age group, 1991-2001; (3) total pedalcyclist…

  12. Children. Traffic Safety Facts, 2000.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document provides statistical information on the incidence of U.S. motor vehicle-related accidents and fatalities involving children. Data include: (1) total traffic fatalities among children 0-14 years old, by age group, 1990-2000; (2) total pedestrian fatalities among children 0-14 years old, by age group, 1990-2000; (3) total pedalcyclist…

  13. Air-traffic surveillance systems

    NASA Technical Reports Server (NTRS)

    Macdoran, P. F.

    1979-01-01

    Passive ground-based radio-interferometry systems (RILS) monitor local air traffic by determining aircraft position in planes defined by surveillance area. Similar RILS arrangements are used to determine aircraft positions in three dimensions when combined with azimuth and range information obtained by radar. Information helps determine three-dimensional aircraft position without expensive encoding altimeters.

  14. Broadcast control of air traffic

    NASA Technical Reports Server (NTRS)

    Litchford, G. B.

    1972-01-01

    The development of a system of broadcast control for improved flight safety and air traffic control is discussed. The system provides a balance of equality between improved cockpit guidance and control capability and ground control in order to provide the pilot with a greater degree of participation. The manner in which the system is operated and the equipment required for safe operation are examined.

  15. The traffic crisis and a tale of two cities: Traffic and air quality in Bangkok and Mexico City

    SciTech Connect

    Pendakur, V.S.; Badami, M.G.

    1995-12-31

    This paper focuses on congestion management techniques, traffic congestion levels and air quality. By using data from Bangkok and Mexico City, it illustrates the need for drastic changes in transportation policy tools and techniques for congestion management and for improving environmental quality. New approaches to investment and regulatory policy analysis and implementation are suggested. This requires the inclusion of all costs and benefits (economic and ecological) in the policy matrix so that investment and regulatory policies act in unison. Megacities are dominant in social, political and economic terms. 30 to 60% of national GDP is typically produced in these cities. Their human and motor vehicle populations have been doubling every 15-20 and 6-10 years respectively. They also have the most severe traffic congestion and air quality problems. They have the nation`s highest incidence of poverty and absolute poverty. Large portions of their populations endure severely unhealthy housing and sanitation conditions. Following are important characteristics of urban transportation systems in the megacities: the city centres are heavily congested with motorized traffic; traffic crawl rates vary from 2 to 10 km/hr; car and motorcycle ownership are increasing at annual rates of 10-12% and 15-20% respectively; significant air pollution with no relief in sight; TDM strategies are primarily creating new supply of road capacity; fairly high transit trips with substantial transit investments; weak air pollution monitoring and enforcement; and fairly cheap fuel and high costs of vehicles.

  16. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 8 2012-10-01 2012-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual...

  17. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 8 2013-10-01 2013-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual...

  18. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of...

  19. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of...

  20. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of...

  1. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of...

  2. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual...

  3. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual...

  4. 49 CFR 1139.2 - Traffic study.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 false Traffic study. 1139.2 Section 1139.2... of General Commodities § 1139.2 Traffic study. (a) The respondents shall submit a traffic study for... “base-calendar year—actual.” The study shall include a probability sampling of the actual...

  5. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL...

  6. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL...

  7. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of...

  8. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of...

  9. 15 CFR 265.22 - Bicycle traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Bicycle traffic. 265.22 Section 265.22... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS &...

  10. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  11. 15 CFR 265.22 - Bicycle traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Bicycle traffic. 265.22 Section 265.22... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS &...

  12. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio...

  13. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  14. 15 CFR 265.22 - Bicycle traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Bicycle traffic. 265.22 Section 265.22... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS &...

  15. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  16. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Traffic control. 57.9100 Section 57.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of...

  17. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio...

  18. 15 CFR 265.22 - Bicycle traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Bicycle traffic. 265.22 Section 265.22... STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS &...

  19. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  20. 49 CFR 236.381 - Traffic locking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Traffic locking. 236.381 Section 236.381 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.381 Traffic locking. Traffic locking shall be tested when placed in service...

  1. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio...

  2. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio...

  3. 36 CFR 1004.13 - Obstructing traffic.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Obstructing traffic. 1004.13 Section 1004.13 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.13 Obstructing traffic. The following are prohibited: (a) Stopping or parking a vehicle upon a Presidio...

  4. Predicting Information Flows in Network Traffic.

    ERIC Educational Resources Information Center

    Hinich, Melvin J.; Molyneux, Robert E.

    2003-01-01

    Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

  5. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Traffic control. 56.9100 Section 56.9100 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of...

  6. Reversible Discrete Event Formulation and Optimistic Parallel Execution of Vehicular Traffic Models

    SciTech Connect

    Yoginath, Srikanth B; Perumalla, Kalyan S

    2009-01-01

    Vehicular traffic simulations are useful in applications such as emergency planning and traffic management. High speed of traffic simulations translates to speed of response and level of resilience in those applications. Discrete event formulation of traffic flow at the level of individual vehicles affords both the flexibility of simulating complex scenarios of vehicular flow behavior as well as rapid simulation time advances. However, efficient parallel/distributed execution of the models becomes challenging due to synchronization overheads. Here, a parallel traffic simulation approach is presented that is aimed at reducing the time for simulating emergency vehicular traffic scenarios. Our approach resolves the challenges that arise in parallel execution of microscopic, vehicular-level models of traffic. We apply a reverse computation-based optimistic execution approach to address the parallel synchronization problem. This is achieved by formulating a reversible version of a discrete event model of vehicular traffic, and by utilizing this reversible model in an optimistic execution setting. Three unique aspects of this effort are: (1) exploration of optimistic simulation applied to vehicular traffic simulation (2) addressing reverse computation challenges specific to optimistic vehicular traffic simulation (3) achieving absolute (as opposed to self-relative) speedup with a sequential speed close to that of a fast, de facto standard sequential simulator for emergency traffic. The design and development of the parallel simulation system is presented, along with a performance study that demonstrates excellent sequential performance as well as parallel performance. The benefits of optimistic execution are demonstrated, including a speed up of nearly 20 on 32 processors observed on a vehicular network of over 65,000 intersections and over 13 million vehicles.

  7. Road Traffic Accidents in Kazakhstan

    PubMed Central

    AUBAKIROVA, Alma; KOSSUMOV, Alibek; IGISSINOV, Nurbek

    2013-01-01

    Background: The article provides the analysis of death rates in road traffic accidents in Kazakhstan from 2004 to 2010 and explores the use of sanitary aviation. Methods: Data of fatalities caused by road traffic accidents were collected and analysed. Descriptive and analytical methods of epidemiology and biomedical statistics were applied. Results: Totaly 27,003 people died as a result of road traffic accidents in this period. The death rate for the total population due to road traffic accidents was 25.0±2.10/0000. The death rate for men was (38.3±3.20/0000), which was higher (P<0.05) than that for women (12.6±1.10/0000). High death rates in the entire male population were identified among men of 30–39 years old, whereas the highest rates for women were attributed to the groups of 50–59 years old and 70–79 years old. In time dynamics, death rates tended to decrease: the total population (Tdec=−2.4%), men (Tdec=−2.3%) and women (Tdec=−1.4%). When researching territorial relevance, the rates were established as low (to 18.30/0000), average (between 18.3 and 24.00/0000) and high (from 24.00/0000 and above). Thus, the regions with high rates included Akmola region (24.30/0000), Mangistau region (25.90/0000), Zhambyl region (27.30/0000), Almaty region (29.30/0000) and South Kazakhstan region (32.40/0000). Conclusion: The identified epidemiological characteristics of the population deaths rates from road traffic accidents should be used in integrated and targeted interventions to enhance prevention of injuries in accidents. PMID:23641400

  8. Cellular automata model for urban road traffic flow considering pedestrian crossing street

    NASA Astrophysics Data System (ADS)

    Zhao, Han-Tao; Yang, Shuo; Chen, Xiao-Xu

    2016-11-01

    In order to analyze the effect of pedestrians' crossing street on vehicle flows, we investigated traffic characteristics of vehicles and pedestrians. Based on that, rules of lane changing, acceleration, deceleration, randomization and update are modified. Then we established two urban two-lane cellular automata models of traffic flow, one of which is about sections with non-signalized crosswalk and the other is on uncontrolled sections with pedestrians crossing street at random. MATLAB is used for numerical simulation of the different traffic conditions; meanwhile space-time diagram and relational graphs of traffic flow parameters are generated and then comparatively analyzed. Simulation results indicate that when vehicle density is lower than around 25 vehs/(km lane), pedestrians have modest impact on traffic flow, whereas when vehicle density is higher than about 60 vehs/(km lane), traffic speed and volume will decrease significantly especially on sections with non-signal-controlled crosswalk. The results illustrate that the proposed models reconstruct the traffic flow's characteristic with the situation where there are pedestrians crossing and can provide some practical reference for urban traffic management.

  9. Dynamic analysis of traffic time series at different temporal scales: A complex networks approach

    NASA Astrophysics Data System (ADS)

    Tang, Jinjun; Wang, Yinhai; Wang, Hua; Zhang, Shen; Liu, Fang

    2014-07-01

    The analysis of dynamics in traffic flow is an important step to achieve advanced traffic management and control in Intelligent Transportation System (ITS). Complexity and periodicity are definitely two fundamental properties in traffic dynamics. In this study, we first measure the complexity of traffic flow data by Lempel-Ziv algorithm at different temporal scales, and the data are collected from loop detectors on freeway. Second, to obtain more insight into the complexity and periodicity in traffic time series, we then construct complex networks from traffic time series by considering each day as a cycle and each cycle as a single node. The optimal threshold value of complex networks is estimated by the distribution of density and its derivative. In addition, the complex networks are subsequently analyzed in terms of some statistical properties, such as average path length, clustering coefficient, density, average degree and betweenness. Finally, take 2 min aggregation data as example, we use the correlation coefficient matrix, adjacent matrix and closeness to exploit the periodicity of weekdays and weekends in traffic flow data. The findings in this paper indicate that complex network is a practical tool for exploring dynamics in traffic time series.

  10. Analysis of road traffic obstructions caused by the central European flood in June 2013 in Germany

    NASA Astrophysics Data System (ADS)

    Bessel, Tina

    2014-05-01

    The flood in June 2013 caused in Germany severe damage to infrastructure and has had a great impact on transportation. Traffic was disrupted in the interregional transportation network including federal highways and long distance railways. Researchers from the Center for Disaster Management and Risk Reduction Technology (CEDIM) aim to develop rapid assessment tools which allow a science based estimation of disaster impacts. This is part of a larger project called Forensic Disaster Analysis (FDA). During the flood event, the CEDIM FDA group on transportation disruptions monitored and recorded traffic reports in Germany to obtain accurate information on road traffic obstructions due to the flood. A rapid initial evaluation of the data was carried out for federal and interstate highways on a district level for the period of May 31 till June 4 2013. In this evaluation, the causes and types of traffic obstruction, as well as the number and duration of flood-caused disruptions are considered. In the evaluated time period of five days, an amount of more than 4,800 hours of flood-related traffic obstructions could be observed in a total of 89 districts. Major traffic disruptions were located in the districts along the Mulde and in the foothills of the Alps. This first initial evaluation will be followed by a detailed statistical analysis including all data collected during the flood event. To assess the impacts of the flood on traffic, a simple traffic simulation considering the disruptions will be carried out using a gravity model.

  11. Traffic flow theory and traffic flow simulation models. Transportation research record

    SciTech Connect

    1996-12-31

    ;Contents: Comparison of Simulation Modules of TRANSYT and INTEGRATION Models; Evaluation of SCATSIM-RTA Adaptive Traffic Network Simulation Model; Comparison NETSIM, NETFLO I, and NETFLO II Traffic Simulation Models for Fixed-Time Signal Control; Traffic Flow Simulation Through Parallel Processing; Cluster Analysis as Tool in Traffic Engineering; Traffic Platoon Dispersion Modeling on Arterial Streets; Hybrid Model for Estimating Permitted Left-Turn Saturations Flow Rate; and Passing Sight Distance and Overtaking Dilemma on Two-Lane Roads.

  12. 41 CFR 102-74.430 - What is the policy concerning vehicular and pedestrian traffic on Federal property?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false What is the policy... Pedestrian Traffic § 102-74.430 What is the policy concerning vehicular and pedestrian traffic on Federal... platforms, or fire hydrants; and (f) Are prohibited from parking on Federal property without a...

  13. Building the Brain's "Air Traffic Control" System: How Early Experiences Shape the Development of Executive Function. Working Paper 11

    ERIC Educational Resources Information Center

    National Scientific Council on the Developing Child, 2011

    2011-01-01

    Being able to focus, hold, and work with information in mind, filter distractions, and switch gears is like having an air traffic control system at a busy airport to manage the arrivals and departures of dozens of planes on multiple runways. In the brain, this air traffic control mechanism is called executive functioning, a group of skills that…

  14. Simulation Study of Traffic Accidents in Bidirectional Traffic Models

    NASA Astrophysics Data System (ADS)

    Moussa, Najem

    Conditions for the occurrence of bidirectional collisions are developed based on the Simon-Gutowitz bidirectional traffic model. Three types of dangerous situations can occur in this model. We analyze those corresponding to head-on collision; rear-end collision and lane-changing collision. Using Monte Carlo simulations, we compute the probability of the occurrence of these collisions for different values of the oncoming cars' density. It is found that the risk of collisions is important when the density of cars in one lane is small and that of the other lane is high enough. The influence of different proportions of heavy vehicles is also studied. We found that heavy vehicles cause an important reduction of traffic flow on the home lane and provoke an increase of the risk of car accidents.

  15. Road-traffic pollution and asthma – using modelled exposure assessment for routine public health surveillance

    PubMed Central

    Ferguson, Elspeth C; Maheswaran, Ravi; Daly, Mark

    2004-01-01

    Asthma is a common disease and appears to be increasing in prevalence. There is evidence linking air pollution, including that from road-traffic, with asthma. Road traffic is also on the increase. Routine surveillance of the impact of road-traffic pollution on asthma, and other diseases, would be useful in informing local and national government policy in terms of managing the environmental health risk. Several methods for exposure assessment have been used in studies examining the association between asthma and road traffic pollution. These include comparing asthma prevalence in areas designated as high and low pollution areas, using distance from main roads as a proxy for exposure to road traffic pollution, using traffic counts to estimate exposure, using vehicular miles travelled and using modelling techniques. Although there are limitations to all these methods, the modelling approach has the advantage of incorporating several variables and may be used for prospective health impact assessment. The modelling approach is already in routine use in the United Kingdom in support of the government's strategy for air quality management. Combining information from such models with routinely collected health data would form the basis of a routine public health surveillance system. Such a system would facilitate prospective health impact assessment, enabling policy decisions concerned with road-traffic to be made with knowledge of the potential implications. It would also allow systematic monitoring of the health impacts when the policy decisions and plans have been implemented. PMID:15485575

  16. The car following model considering traffic jerk

    NASA Astrophysics Data System (ADS)

    Ge, Hong-Xia; Zheng, Peng-jun; Wang, Wei; Cheng, Rong-Jun

    2015-09-01

    Based on optimal velocity car following model, a new model considering traffic jerk is proposed to describe the jamming transition in traffic flow on a highway. Traffic jerk means the sudden braking and acceleration of vehicles, which has a significant impact on traffic movement. The nature of the model is researched by using linear and nonlinear analysis method. A thermodynamic theory is formulated to describe the phase transition and critical phenomenon in traffic flow. The time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are derived to describe the traffic flow near the critical point and the traffic jam. In addition, the connection between the TDGL and the mKdV equations are also given.

  17. Interaction Between Strategic and Local Traffic Flow Controls

    NASA Technical Reports Server (NTRS)

    Grabbe, Son; Sridhar, Banavar; Mukherjee, Avijit; Morando, Alexander

    2010-01-01

    The loosely coordinated sets of traffic flow management initiatives that are operationally implemented at the national- and local-levels have the potential to under, over, and inconsistently control flights. This study is designed to explore these interactions through fast-time simulations with an emphasis on identifying inequitable situations in which flights receive multiple uncoordinated delays. Two operationally derived scenarios were considered in which flights arriving into the Dallas/Fort Worth International Airport were first controlled at the national-level, either with a Ground Delay Program or a playbook reroute. These flights were subsequently controlled at the local level. The Traffic Management Advisor assigned them arrival scheduling delays. For the Ground Delay Program scenarios, between 51% and 53% of all arrivals experience both pre-departure delays from the Ground Delay Program and arrival scheduling delays from the Traffic Management Advisor. Of the subset of flights that received multiple delays, between 5.7% and 6.4% of the internal departures were first assigned a pre-departure delay by the Ground Delay Program, followed by a second pre-departure delay as a result of the arrival scheduling. For the playbook reroute scenario, Dallas/Fort Worth International Airport arrivals were first assigned pre-departure reroutes based on the MW_2_DALLAS playbook plan, and were subsequently assigned arrival scheduling delays by the Traffic Management Advisor. Since the airport was operating well below capacity when the playbook reroute was in effect, only 7% of the arrivals were observed to receive both rerouting and arrival scheduling delays. Findings from these initial experiments confirm field observations that Ground Delay Programs operated in conjunction with arrival scheduling can result in inequitable situations in which flights receive multiple uncoordinated delays.

  18. Crowding Effects in Vehicular Traffic

    PubMed Central

    Combinido, Jay Samuel L.; Lim, May T.

    2012-01-01

    While the impact of crowding on the diffusive transport of molecules within a cell is widely studied in biology, it has thus far been neglected in traffic systems where bulk behavior is the main concern. Here, we study the effects of crowding due to car density and driving fluctuations on the transport of vehicles. Using a microscopic model for traffic, we found that crowding can push car movement from a superballistic down to a subdiffusive state. The transition is also associated with a change in the shape of the probability distribution of positions from a negatively-skewed normal to an exponential distribution. Moreover, crowding broadens the distribution of cars’ trap times and cluster sizes. At steady state, the subdiffusive state persists only when there is a large variability in car speeds. We further relate our work to prior findings from random walk models of transport in cellular systems. PMID:23139762

  19. Crowding effects in vehicular traffic.

    PubMed

    Combinido, Jay Samuel L; Lim, May T

    2012-01-01

    While the impact of crowding on the diffusive transport of molecules within a cell is widely studied in biology, it has thus far been neglected in traffic systems where bulk behavior is the main concern. Here, we study the effects of crowding due to car density and driving fluctuations on the transport of vehicles. Using a microscopic model for traffic, we found that crowding can push car movement from a superballistic down to a subdiffusive state. The transition is also associated with a change in the shape of the probability distribution of positions from a negatively-skewed normal to an exponential distribution. Moreover, crowding broadens the distribution of cars' trap times and cluster sizes. At steady state, the subdiffusive state persists only when there is a large variability in car speeds. We further relate our work to prior findings from random walk models of transport in cellular systems.

  20. The Monotonic Lagrangian Grid for Rapid Air-Traffic Evaluation

    NASA Technical Reports Server (NTRS)

    Kaplan, Carolyn; Dahm, Johann; Oran, Elaine; Alexandrov, Natalia; Boris, Jay

    2010-01-01

    The Air Traffic Monotonic Lagrangian Grid (ATMLG) is presented as a tool to evaluate new air traffic system concepts. The model, based on an algorithm called the Monotonic Lagrangian Grid (MLG), can quickly sort, track, and update positions of many aircraft, both on the ground (at airports) and in the air. The underlying data structure is based on the MLG, which is used for sorting and ordering positions and other data needed to describe N moving bodies and their interactions. Aircraft that are close to each other in physical space are always near neighbors in the MLG data arrays, resulting in a fast nearest-neighbor interaction algorithm that scales as N. Recent upgrades to ATMLG include adding blank place-holders within the MLG data structure, which makes it possible to dynamically change the MLG size and also improves the quality of the MLG grid. Additional upgrades include adding FAA flight plan data, such as way-points and arrival and departure times from the Enhanced Traffic Management System (ETMS), and combining the MLG with the state-of-the-art strategic and tactical conflict detection and resolution algorithms from the NASA-developed Stratway software. In this paper, we present results from our early efforts to couple ATMLG with the Stratway software, and we demonstrate that it can be used to quickly simulate air traffic flow for a very large ETMS dataset.

  1. CG Vessel Traffic Service Program.

    DTIC Science & Technology

    1980-06-01

    the plan called for the construction of a traffic control center, seven remote communications sites linked to the control center by microwave equipment...three or four remote LLLTV sites. 40 In New Orleans, as in New York, the potential for catastrophe cannot be discounted, as vessel density is high and...your RCP simply will not fit a literal use of the question’s wording, base your score on the sense of the wording in the context of the whole question

  2. Transition characteristic analysis of traffic evolution process for urban traffic network.

    PubMed

    Wang, Longfei; Chen, Hong; Li, Yang

    2014-01-01

    The characterization of the dynamics of traffic states remains fundamental to seeking for the solutions of diverse traffic problems. To gain more insights into traffic dynamics in the temporal domain, this paper explored temporal characteristics and distinct regularity in the traffic evolution process of urban traffic network. We defined traffic state pattern through clustering multidimensional traffic time series using self-organizing maps and construct a pattern transition network model that is appropriate for representing and analyzing the evolution progress. The methodology is illustrated by an application to data flow rate of multiple road sections from Network of Shenzhen's Nanshan District, China. Analysis and numerical results demonstrated that the methodology permits extracting many useful traffic transition characteristics including stability, preference, activity, and attractiveness. In addition, more information about the relationships between these characteristics was extracted, which should be helpful in understanding the complex behavior of the temporal evolution features of traffic patterns.

  3. Selection and allocation of manual traffic control points and personnel during emergencies.

    PubMed

    Parr, Scott A; Wolshon, Brian; Dixit, Vinayak

    2015-01-01

    Manual traffic control is an intersection control strategy in which law enforcement officers allocate intersection right-of-way to turning movements. Many emergency traffic management plans call for manual traffic control in response to oversaturated roadway conditions. This is because it is thought to more effectively move traffic during temporary surges in demand. The goal of this research was to evaluate the current state-of-the-practice used by the Army Corps of Engineers (ACE) in selecting intersections for manual traffic control and allocating police personnel to them during emergencies. This research uses the emergency traffic management plans developed by the ACE for nine counties in the Maryland Eastern Shore region. This area encompassing 14,318 intersections of which 74 were selected for manual traffic control during emergencies. This work sought to quantify the correlations that exist between intersection attributes and the ACE' decision to allocate officers to control them. The research findings suggest that US routes, State routes, and emergency evacuation routes are statistically significant in determining the need for police control at intersections. Also significant are intersection on contraflow corridors and intersections near grade separated interchanges. The model also determined that intersections isolated from evacuation routes and county exits were more likely to be selected for manual control, indicating that rural areas may rely on manual traffic control in the absence of multilane highway and freeways. This research also found that intersections involving evacuation routes, contraflow corridors, and grade separated interchanges may warrant additional police personnel (two or more officers) for manual traffic control.

  4. enviroCar - citizen science for sustainable traffic

    NASA Astrophysics Data System (ADS)

    Stasch, Christoph; Remke, Albert; Jirka, Simon; Nuest, Daniel

    2015-04-01

    Optimizing traffic flow is a challenging task, affecting both the mobility of people and the environment. Up to now, traffic monitoring is based on small samples using GPS devices or remote sensors such as cameras. Citizens are usually not actively involved in the process of collecting or analyzing traffic data. The enviroCar project (www.envirocar.org) aims at addressing this situation by providing an open platform that can be used by everyone to collect and analyze traffic-related data and thus to achieve sustainable traffic management by answering questions such as: How is the average speed on a certain route? Where are exceptionally long waiting times in front of traffic lights? At which crossings do more cars stop than drive through? Where are hotspots of fuel consumption and air pollutant emission during a certain time interval? In this presentation, an overview on the enviroCar project is given and current research challenges addressed in the context of the project are presented. Citizens are able to participate by registering at the enviroCar portal and downloading the enviroCar Android app. Once installed, the Android app allows citizens to collect car sensor data, e.g. speed, mass air flow, or intake temperature via an On-Board Diagnosis 2 (OBD-II) Adapter. After finishing a car ride, the data can be uploaded to the central enviroCar server where the data is anonymized and published as open data. Each enviroCar member has a profile page giving control on his own data and providing statistics on personal driving behavior. The portal also allows comparing personal statistics with the statistics of other members. It thus facilitates analysis whether, for example, a member is driving in a more fuel saving manner than other users. Besides only acting as a data collector, citizens can also explore the enviroCar data in online maps or download the data in standard formats for certain spatial areas and/or time intervals allowing them to conduct spatio

  5. 23 CFR 500.204 - TMS components for highway traffic data.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... INFRASTRUCTURE MANAGEMENT MANAGEMENT AND MONITORING SYSTEMS Traffic Monitoring System § 500.204 TMS components... classification activities on the National Highway System (NHS), shall be sufficient to assure that, on a cycle of no greater than three years, every major system segment (i.e., segments between interchanges...

  6. Traffic Instabilities in Self-Organized Pedestrian Crowds

    PubMed Central

    Moussaïd, Mehdi; Guillot, Elsa G.; Moreau, Mathieu; Fehrenbach, Jérôme; Chabiron, Olivier; Lemercier, Samuel; Pettré, Julien; Appert-Rolland, Cécile; Degond, Pierre; Theraulaz, Guy

    2012-01-01

    In human crowds as well as in many animal societies, local interactions among individuals often give rise to self-organized collective organizations that offer functional benefits to the group. For instance, flows of pedestrians moving in opposite directions spontaneously segregate into lanes of uniform walking directions. This phenomenon is often referred to as a smart collective pattern, as it increases the traffic efficiency with no need of external control. However, the functional benefits of this emergent organization have never been experimentally measured, and the underlying behavioral mechanisms are poorly understood. In this work, we have studied this phenomenon under controlled laboratory conditions. We found that the traffic segregation exhibits structural instabilities characterized by the alternation of organized and disorganized states, where the lifetime of well-organized clusters of pedestrians follow a stretched exponential relaxation process. Further analysis show that the inter-pedestrian variability of comfortable walking speeds is a key variable at the origin of the observed traffic perturbations. We show that the collective benefit of the emerging pattern is maximized when all pedestrians walk at the average speed of the group. In practice, however, local interactions between slow- and fast-walking pedestrians trigger global breakdowns of organization, which reduce the collective and the individual payoff provided by the traffic segregation. This work is a step ahead toward the understanding of traffic self-organization in crowds, which turns out to be modulated by complex behavioral mechanisms that do not always maximize the group's benefits. The quantitative understanding of crowd behaviors opens the way for designing bottom-up management strategies bound to promote the emergence of efficient collective behaviors in crowds. PMID:22457615

  7. STOP: Can We Minimize OR Traffic?

    PubMed

    Elliott, Sara; Parker, Stacy; Mills, Judi; Meeusen, Lindsay; Frana, Theresa; Anderson, Marie; Storsveen, Amy; White, Amy

    2015-10-01

    Perioperative nurses at our institution voiced concerns about the amount of traffic in the ORs. We formed a workgroup consisting of perioperative nurses, educators, and leaders and initiated a quality improvement (QI) project to identify the amount of OR traffic that occurs during a procedure. The workgroup developed a check sheet to record door swings, staff classifications, reasons for opening the door, and the number of people in the OR at 15-minute intervals. Baseline results showed that average door swings ranged from 33 per hour in general surgery to 54 per hour in cardiac surgery. Nurses accounted for the most traffic, citing retrieving supplies as the main reason. Interventions focused on decreasing nurse traffic for retrieval of supplies in general surgery. Follow-up observations showed that average door swings increased to 41 per hour in general surgery, but nurse traffic decreased. Monitoring and limiting traffic could positively affect patient safety and outcomes.

  8. A System for Traffic Violation Detection

    PubMed Central

    Aliane, Nourdine; Fernandez, Javier; Mata, Mario; Bemposta, Sergio

    2014-01-01

    This paper describes the framework and components of an experimental platform for an advanced driver assistance system (ADAS) aimed at providing drivers with a feedback about traffic violations they have committed during their driving. The system is able to detect some specific traffic violations, record data associated to these faults in a local data-base, and also allow visualization of the spatial and temporal information of these traffic violations in a geographical map using the standard Google Earth tool. The test-bed is mainly composed of two parts: a computer vision subsystem for traffic sign detection and recognition which operates during both day and nighttime, and an event data recorder (EDR) for recording data related to some specific traffic violations. The paper covers firstly the description of the hardware architecture and then presents the policies used for handling traffic violations. PMID:25421737

  9. Game theory model of traffic participants within amber time at signalized intersection.

    PubMed

    Qi, Weiwei; Wen, Huiying; Fu, Chuanyun; Song, Mo

    2014-01-01

    The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy.

  10. Game Theory Model of Traffic Participants within Amber Time at Signalized Intersection

    PubMed Central

    Qi, Weiwei; Wen, Huiying; Fu, Chuanyun; Song, Mo

    2014-01-01

    The traffic light scheme is composed of red, green, and amber lights, and it has been defined clearly for the traffic access of red and green lights; however, the definition of that for the amber light is indistinct, which leads to the appearance of uncertainty factors and serious traffic conflicts during the amber light. At present, the traffic administrations are faced with the decision of whether to forbid passing or not during the amber light in the cities of China. On one hand, it will go against the purpose of setting amber lights if forbidding passing; on the other hand, it may lead to a mess of traffic flow running if not. And meanwhile the drivers are faced with the decision of passing the intersection or stopping during the amber light as well. So the decision-making behavior of traffic administrations and drivers can be converted into a double game model. And through quantification of their earnings in different choice conditions, the optimum decision-making plan under specific conditions could be solved via the Nash equilibrium solution concept. Thus the results will provide a basis for the formulation of the traffic management strategy. PMID:25580108

  11. Understanding crash mechanism on urban expressways using high-resolution traffic data.

    PubMed

    Hossain, Moinul; Muromachi, Yasunori

    2013-08-01

    Urban expressways play a vital role in the modern mega cities by serving peak hour traffic alongside reducing travel time for moderate to long distance intra-city trips. Thus, ensuring safety on these roads holds high priority. Little knowledge has been acquired till date regarding crash mechanism on these roads. This study uses high-resolution traffic data collected from the detectors to identify factors influencing crash. It also identifies traffic patterns associated with different types of crashes and explains crash phenomena thereby. Unlike most of the previous studies on conventional expressways, the research separately investigates the basic freeway segments (BFS) and the ramp areas. The study employs random multinomial logit, a random forest of logit models, to rank the variables; expectation maximization clustering algorithm to identify crash prone traffic patterns and classification and regression trees to explain crash phenomena. As accentuated by the study outcome, crash mechanism is not generic throughout the expressway and it varies from the BFS to the ramp vicinities. The level of congestion and speed difference between upstream and downstream traffic best explains crashes and their types for the BFS, whereas, the ramp flow has the highest influence in determining the types of crashes within the ramp vicinities. The paper also discusses about the applicability of different countermeasures, such as, variable speed limits, temporary restriction on lane changing, posting warnings, etc., to attenuate different patterns of hazardous traffic conditions. The study outcome can be utilized in designing location and traffic condition specific proactive road safety management systems for urban expressways.

  12. Empirical synchronized flow in oversaturated city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Hemmerle, Peter; Koller, Micha; Hermanns, Gerhard; Klenov, Sergey L.; Rehborn, Hubert; Schreckenberg, Michael

    2014-09-01

    Based on a study of anonymized GPS probe vehicle traces measured by personal navigation devices in vehicles randomly distributed in city traffic, empirical synchronized flow in oversaturated city traffic has been revealed. It turns out that real oversaturated city traffic resulting from speed breakdown in a city in most cases can be considered random spatiotemporal alternations between sequences of moving queues and synchronized flow patterns in which the moving queues do not occur.

  13. Empirical synchronized flow in oversaturated city traffic.

    PubMed

    Kerner, Boris S; Hemmerle, Peter; Koller, Micha; Hermanns, Gerhard; Klenov, Sergey L; Rehborn, Hubert; Schreckenberg, Michael

    2014-09-01

    Based on a study of anonymized GPS probe vehicle traces measured by personal navigation devices in vehicles randomly distributed in city traffic, empirical synchronized flow in oversaturated city traffic has been revealed. It turns out that real oversaturated city traffic resulting from speed breakdown in a city in most cases can be considered random spatiotemporal alternations between sequences of moving queues and synchronized flow patterns in which the moving queues do not occur.

  14. Network traffic analysis using dispersion patterns

    SciTech Connect

    Khan, F. N.

    2010-03-15

    The Verilog code us used to map a measurement solution on FPGA to analyze network traffic. It realizes a set of Bloom filters and counters, besides associated control logic that can quickly measure statistics like InDegree, OutDegree, Depth, in the context of Traffic Dispersion Graphs. Such patterns are helpful in classification of network activity, like Peer to Peer and Port-Scanning, in the traffic.

  15. STOL Traffic environment and operational procedures

    NASA Technical Reports Server (NTRS)

    Schlundt, R. W.; Dewolf, R. W.; Ausrotas, R. A.; Curry, R. E.; Demaio, D.; Keene, D. W.; Speyer, J. L.; Weinreich, M.; Zeldin, S.

    1972-01-01

    The expected traffic environment for an intercity STOL transportation system is examined, and operational procedures are discussed in order to identify problem areas which impact STOL avionics requirements. Factors considered include: traffic densities, STOL/CTOL/VTOL traffic mix, the expect ATC environment, aircraft noise models and community noise models and community noise impact, flight paths for noise abatement, wind considerations affecting landing, approach and landing considerations, STOLport site selection, runway capacity, and STOL operations at jetports, suburban airports, and separate STOLports.

  16. ATM traffic-policing and traffic-shaping measurements

    NASA Astrophysics Data System (ADS)

    Pugaczewski, Jack T.; Sanderson, Dave; Hoffman, David W.

    1997-10-01

    ATM (Asynchronous Transfer Mode) defines several Quality of Service (QoS) levels such as CBR (Constant Bit Rate) and VBR (Variable Bit Rate). Each service has parameters that are associated with its performance characteristic. The parameters used for specifying CBR service are Peak Cell Rate (PCR) and Cell Delay Variation Tolerance (CDVTOL). The parameters used for specifying VBR service are PCR, SCR (Sustainable Cell Rate), and BT (Burst Tolerance). The network takes responsibility for monitoring and policing the traffic of each VCC/VPC at the ingress of the network. The CPE needs to traffic shape at the ingress of the network in order to meet the contracted QoS requirements. Measurement procedures and tools are required in order to provide a means of tuning the CPE and network service to meet the customer's end-to-end QoS expectations. The following paper describes how the Generic Cell Rate Algorithm variables can be adjusted to provide acceptable levels of QoS in a mixed VBR, and CBR environment. In addition, the paper examines a methodology for measuring the performance of VBR and CBR services. The authors uses this information to build a QoS measurement tool.

  17. Studies of vehicle lane-changing dynamics and its effect on traffic efficiency, safety and environmental impact

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Sun, Jian-Qiao

    2017-02-01

    Drivers often change lanes on the road to maintain desired speed and to avoid slow vehicles, pedestrians, obstacles and lane closure. Understanding the effect of lane-changing on the traffic is an important topic in designing optimal traffic control systems. This paper presents a comprehensive study of this topic. We review the theory of microscopic dynamic car-following models and the lane-changing models, propose additional lane-changing rules to deal with moving bottleneck and lane reduction, and investigate the effects of lane-changing on the traffic efficiency, traffic safety and fuel consumption as a function of different variables including the distance of the emergency sign ahead of the lane closure, speed limit, traffic density, etc. Extensive simulations of the traffic system have been carried out in different scenarios. A number of important findings of the effect of various factors on the traffic are reported. These findings provide guidance on the traffic management and are important to the designers and engineers of modern highway or inner city roads to achieve high traffic efficiency and safety with minimum environmental impact.

  18. Temporal Statistic of Traffic Accidents in Turkey

    NASA Astrophysics Data System (ADS)

    Erdogan, S.; Yalcin, M.; Yilmaz, M.; Korkmaz Takim, A.

    2015-10-01

    Traffic accidents form clusters in terms of geographic space and over time which themselves exhibit distinct spatial and temporal patterns. There is an imperative need to understand how, where and when traffic accidents occur in order to develop appropriate accident reduction strategies. An improved understanding of the location, time and reasons for traffic accidents makes a significant contribution to preventing them. Traffic accident occurrences have been extensively studied from different spatial and temporal points of view using a variety of methodological approaches. In literature, less research has been dedicated to the temporal patterns of traffic accidents. In this paper, the numbers of traffic accidents are normalized according to the traffic volume and the distribution and fluctuation of these accidents is examined in terms of Islamic time intervals. The daily activities and worship of Muslims are arranged according to these time intervals that are spaced fairly throughout the day according to the position of the sun. The Islamic time intervals are never been used before to identify the critical hour for traffic accidents in the world. The results show that the sunrise is the critical time that acts as a threshold in the rate of traffic accidents throughout Turkey in Islamic time intervals.

  19. A queuing model for road traffic simulation

    SciTech Connect

    Guerrouahane, N.; Aissani, D.; Bouallouche-Medjkoune, L.; Farhi, N.

    2015-03-10

    We present in this article a stochastic queuing model for the raod traffic. The model is based on the M/G/c/c state dependent queuing model, and is inspired from the deterministic Godunov scheme for the road traffic simulation. We first propose a variant of M/G/c/c state dependent model that works with density-flow fundamental diagrams rather than density-speed relationships. We then extend this model in order to consider upstream traffic demand as well as downstream traffic supply. Finally, we show how to model a whole raod by concatenating raod sections as in the deterministic Godunov scheme.

  20. Synchronized flow in oversaturated city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.; Hermanns, Gerhard; Hemmerle, Peter; Rehborn, Hubert; Schreckenberg, Michael

    2013-11-01

    Based on numerical simulations with a stochastic three-phase traffic flow model, we reveal that moving queues (moving jams) in oversaturated city traffic dissolve at some distance upstream of the traffic signal while transforming into synchronized flow. It is found that, as in highway traffic [Kerner, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.036110 85, 036110 (2012)], such a jam-absorption effect in city traffic is explained by a strong driver's speed adaptation: Time headways (space gaps) between vehicles increase upstream of a moving queue (moving jam), resulting in moving queue dissolution. It turns out that at given traffic signal parameters, the stronger the speed adaptation effect, the shorter the mean distance between the signal location and the road location at which moving queues dissolve fully and oversaturated traffic consists of synchronized flow only. A comparison of the synchronized flow in city traffic found in this Brief Report with synchronized flow in highway traffic is made.

  1. Some features of traffic accidents

    PubMed Central

    Mackay, G. M.

    1969-01-01

    Some aspects of urban and rural traffic accidents have been studied at the scene of some accidents in Birmingham and the county of Worcestershire. Accidents to pedestrians are essentially an urban problem, occur mainly at low speed, and most of the serious injury comes from the initial contact with the vehicle, rather than from secondary impacts with the road surface. The characteristics of motor-cycle accidents are more varied; in urban areas there are many side impacts, with consequent injury to the lower limbs, while rural collisions are predominantly front on, with a high incidence of head injury. Accidents to car occupants vary according to the environment. PMID:5359948

  2. 32 CFR 634.25 - Installation traffic codes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Installation traffic codes. 634.25 Section 634... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.25 Installation traffic codes. (a) Installation or activity commanders will establish a traffic code for...

  3. 32 CFR 634.25 - Installation traffic codes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Installation traffic codes. 634.25 Section 634... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.25 Installation traffic codes. (a) Installation or activity commanders will establish a traffic code for...

  4. 32 CFR 634.24 - Traffic planning and codes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.24 Traffic... supervision. A traffic supervision program includes traffic circulation planning and control of motor vehicle... engineering representatives from adjacent civil communities must be consulted to ensure the installation...

  5. 14 CFR 93.123 - High density traffic airports.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false High density traffic airports. 93.123... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.123 High density traffic airports. (a) Each of the following airports is designated as a...

  6. 32 CFR 634.44 - The traffic point system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true The traffic point system. 634.44 Section 634.44... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Records and the Traffic Point System § 634.44 The traffic point system. The traffic point system provides a uniform administrative device...

  7. 32 CFR 634.44 - The traffic point system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true The traffic point system. 634.44 Section 634.44... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Records and the Traffic Point System § 634.44 The traffic point system. The traffic point system provides a uniform administrative device...

  8. 32 CFR 634.44 - The traffic point system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true The traffic point system. 634.44 Section 634.44... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Records and the Traffic Point System § 634.44 The traffic point system. The traffic point system provides a uniform administrative device...

  9. 32 CFR 634.44 - The traffic point system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false The traffic point system. 634.44 Section 634.44... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Records and the Traffic Point System § 634.44 The traffic point system. The traffic point system provides a uniform administrative device...

  10. 32 CFR 634.44 - The traffic point system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false The traffic point system. 634.44 Section 634.44... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Records and the Traffic Point System § 634.44 The traffic point system. The traffic point system provides a uniform administrative device...

  11. 14 CFR 93.123 - High density traffic airports.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false High density traffic airports. 93.123... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.123 High density traffic airports. (a) Each of the following airports is designated as a...

  12. 14 CFR 93.123 - High density traffic airports.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false High density traffic airports. 93.123... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.123 High density traffic airports. (a) Each of the following airports is designated as a...

  13. 14 CFR 93.123 - High density traffic airports.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false High density traffic airports. 93.123... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.123 High density traffic airports. (a) Each of the following airports is designated as a...

  14. Monitoring information model for traffic engineering over MPLS VPNs

    NASA Astrophysics Data System (ADS)

    Cherkaoui, Omar; Sarrazin, Alain; Francoeur, Guy; Chen, Ken

    2001-07-01

    Monitoring is the part of Traffic Engineering (TE) that aims at optimizing the use of network resources and assists both in informing the provider and proving to the customer that the service offered respects the SLAs required to optimize the network resources utilization. In this paper, we present a monitoring framework for MPLS-VPN services. We first briefly review MPLS, VPN, NBVPN, Constrained Based Routing to provide a background for the discussion of traffic Engineering. We then discuss the general issues surrounding the design of a MPLS VPN from the point of view of TE and go on to present a management framework that extends the DEN information specific to MPLS VPNs. In this framework, we add policy actions that react dynamically to abnormal results by changing the sampling frequency.

  15. Formal Verification of Air Traffic Conflict Prevention Bands Algorithms

    NASA Technical Reports Server (NTRS)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Dowek, Gilles

    2010-01-01

    In air traffic management, a pairwise conflict is a predicted loss of separation between two aircraft, referred to as the ownship and the intruder. A conflict prevention bands system computes ranges of maneuvers for the ownship that characterize regions in the airspace that are either conflict-free or 'don't go' zones that the ownship has to avoid. Conflict prevention bands are surprisingly difficult to define and analyze. Errors in the calculation of prevention bands may result in incorrect separation assurance information being displayed to pilots or air traffic controllers. This paper presents provably correct 3-dimensional prevention bands algorithms for ranges of track angle; ground speed, and vertical speed maneuvers. The algorithms have been mechanically verified in the Prototype Verification System (PVS). The verification presented in this paper extends in a non-trivial way that of previously published 2-dimensional algorithms.

  16. Advanced Interactive Display Formats for Terminal Area Traffic Control

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Shaviv, G. E.

    1999-01-01

    This research project deals with an on-line dynamic method for automated viewing parameter management in perspective displays. Perspective images are optimized such that a human observer will perceive relevant spatial geometrical features with minimal errors. In order to compute the errors at which observers reconstruct spatial features from perspective images, a visual spatial-perception model was formulated. The model was employed as the basis of an optimization scheme aimed at seeking the optimal projection parameter setting. These ideas are implemented in the context of an air traffic control (ATC) application. A concept, referred to as an active display system, was developed. This system uses heuristic rules to identify relevant geometrical features of the three-dimensional air traffic situation. Agile, on-line optimization was achieved by a specially developed and custom-tailored genetic algorithm (GA), which was to deal with the multi-modal characteristics of the objective function and exploit its time-evolving nature.

  17. 2Loud?: Community mapping of exposure to traffic noise with mobile phones.

    PubMed

    Leao, Simone; Ong, Kok-Leong; Krezel, Adam

    2014-10-01

    Despite ample medical evidence of the adverse impacts of traffic noise on health, most policies for traffic noise management are arbitrary or incomplete, resulting in serious social and economic impacts. Surprisingly, there is limited information about citizen's exposure to traffic noise worldwide. This paper presents the 2Loud? mobile phone application, developed and tested as a methodology to monitor, assess and map the level of exposure to traffic noise of citizens with focus on the night period and indoor locations, since sleep disturbance is one of the major triggers for ill health related to traffic noise. Based on a community participation experiment using the 2Loud? mobile phone application in a region close to freeways in Australia, the results of this research indicates a good level of accuracy for the noise monitoring by mobile phones and also demonstrates significant levels of indoor night exposure to traffic noise in the study area. The proposed methodology, through the data produced and the participatory process involved, can potentially assist in planning and management towards healthier urban environments.

  18. 77 FR 55439 - Vessel Traffic Service Updates, Including Establishment of Vessel Traffic Service Requirements...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-10

    ... SECURITY Coast Guard 33 CFR Part 161 RIN 1625-AB81 Vessel Traffic Service Updates, Including Establishment of Vessel Traffic Service Requirements for Port Arthur, TX and Expansion of VTS Special Operating... Guard proposes to revise and update the Vessel Traffic Service (VTS) regulations in 33 CFR part 161....

  19. 77 FR 64076 - Vessel Traffic Service Updates, Including Establishment of Vessel Traffic Service Requirements...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ... SECURITY Coast Guard 33 CFR Part 161 RIN 1625-AB81 Vessel Traffic Service Updates, Including Establishment of Vessel Traffic Service Requirements for Port Arthur, Texas and Expansion of VTS Special Operating... 10, 2012 (77 FR 55439), which proposes to revise and update the Vessel Traffic Service regulations...

  20. Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

    NASA Technical Reports Server (NTRS)

    Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

    2001-01-01

    Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.