Science.gov

Sample records for area traffic signal control

  1. 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.

  2. 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.

  3. The design of traffic signal coordinated control

    NASA Astrophysics Data System (ADS)

    Guo, Xueting; Sun, Hongsheng; Wang, Xifu

    2017-05-01

    Traffic as the tertiary industry is an important pillar industry to support the normal development of the economy. But now China's road traffic development and economic development has shown a great imbalance and fault phenomenon, which greatly inhibited the normal development of China's economy. Now in many large and medium-sized cities in China are implementing green belt construction. The so-called green band is when the road conditions to meet the conditions for the establishment of the green band, the sections of the intersection of several planning to a traffic coordination control system, so that when the driver at a specific speed can be achieved without stopping the continuous Through the intersection. Green belt can effectively reduce the delay and queuing length of vehicle driving, the normal function of urban roads and reduce the economic losses caused by traffic congestion is a great help. In this paper, the theoretical basis of the design of the coordinated control system is described. Secondly, the green time offset is calculated by the analytic method and the green band is established. And then the VISSIM software is used to simulate the traffic system before and after the improvement. Finally, the results of the two simulations are compared.

  4. Terminal area air traffic control simulation

    NASA Technical Reports Server (NTRS)

    1977-01-01

    To study the impact of advanced aeronautical technologies on operations to and from terminal airports, a computer model of air traffic movements was developed. The advantages of fast-time simulation are discussed, and the arrival scheduling and flight simulation are described. A New York area study, user's guide, and programmer's guide are included.

  5. An extended signal control strategy for urban network traffic flow

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-03-01

    Traffic flow patterns are in general repeated on a daily or weekly basis. To improve the traffic conditions by using the inherent repeatability of traffic flow, a novel signal control strategy for urban networks was developed via iterative learning control (ILC) approach. Rigorous analysis shows that the proposed learning control method can guarantee the asymptotic convergence. The impacts of the ILC-based signal control strategy on the macroscopic fundamental diagram (MFD) were analyzed by simulations on a test road network. The results show that the proposed ILC strategy can evenly distribute the accumulation in the network and improve the network mobility.

  6. Applying Genetic Programming with Substructure Discovery to a Traffic Signal Control Problem

    NASA Astrophysics Data System (ADS)

    Kumagai, Juncichi; Ojima, Yasuo; Takashige, Souichi; Kameya, Yoshitaka; Sato, Taisuke

    Nowadays the increase of traffic causes numerous serious traffic jams, and traffic signals are desired to work adaptively for dynamic traffic flows. In this paper, we view such a problem of traffic signal control as a multi-agent problem where each signal has a controlling agent, and aim to make the agents work cooperatively depending on the traffic status. To build such an agent program automatically, we introduce genetic programming (GP), an evolutionary method for program construction. In GP, it is known as important to encapsulate the substructures of a program which leads to higher fitness to the environment, and we propose a new encapsulation method using an efficient technique for discovering frequent substructures, which has been recently proposed in the data mining field. We also conducted a simulation with a real traffic data, and confirmed that GP with our encapsulation method outperforms the normal GP. It is also observed that the best individual has a communication part that chooses an appropriate communication area and adapts to the traffic status.

  7. A computerized traffic control algorithm to determine optimal traffic signal settings. Ph.D. Thesis - Toledo Univ.

    NASA Technical Reports Server (NTRS)

    Seldner, K.

    1977-01-01

    An algorithm was developed to optimally control the traffic signals at each intersection using a discrete time traffic model applicable to heavy or peak traffic. Off line optimization procedures were applied to compute the cycle splits required to minimize the lengths of the vehicle queues and delay at each intersection. The method was applied to an extensive traffic network in Toledo, Ohio. Results obtained with the derived optimal settings are compared with the control settings presently in use.

  8. Driving behavior and control in traffic system with two kinds of signals

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi; Hino, Yuki

    2014-06-01

    We study the vehicular traffic controlled by two kinds of signals which are positioned with a periodic configuration. We propose a microscopic model to explore the driving behavior in the traffic system with two kinds of signals. The control method of traffic flow by the combination of two kinds of signals is proposed. The dynamic model is described by the nonlinear map model and the CA model. The driving behavior is clarified for the traffic system controlled by two kinds of signals. The fundamental diagrams are derived for various combinations of two kinds of signals. The traffic flow through two kinds of signals is compared with that of a single kind of signals. The traffic flow displays the complex behavior different from the conventional traffic with a single kind of signals.

  9. Exposure to lateral collision in signalized intersections with protected left turn under different traffic control strategies.

    PubMed

    Midenet, Sophie; Saunier, Nicolas; Boillot, Florence

    2011-11-01

    This paper proposes an original definition of the exposure to lateral collision in signalized intersections and discusses the results of a real world experiment. This exposure is defined as the duration of situations where the stream that is given the right-of-way goes through the conflict zone while road users are waiting in the cross-traffic approach. This measure, obtained from video sensors, makes it possible to compare different operating conditions such as different traffic signal strategies. The data from a real world experiment is used, where the adaptive real-time strategy CRONOS (ContRol Of Networks by Optimization of Switchovers) and a time-plan strategy with vehicle-actuated ranges alternately controlled an isolated intersection near Paris. Hourly samples with similar traffic volumes are compared and the exposure to lateral collision is different in various areas of the intersection and various traffic conditions for the two strategies. The total exposure under peak hour traffic conditions drops by roughly 5 min/h with the CRONOS strategy compared to the time-plan strategy, which occurs mostly on entry streams. The results are analyzed through the decomposition of cycles in phase sequences and recommendations are made for traffic control strategies.

  10. A new traffic control design method for large networks with signalized intersections

    NASA Technical Reports Server (NTRS)

    Leininger, G. G.; Colony, D. C.; Seldner, K.

    1979-01-01

    The paper presents a traffic control design technique for application to large traffic networks with signalized intersections. It is shown that the design method adopts a macroscopic viewpoint to establish a new traffic modelling procedure in which vehicle platoons are subdivided into main stream queues and turning queues. Optimization of the signal splits minimizes queue lengths in the steady state condition and improves traffic flow conditions, from the viewpoint of the traveling public. Finally, an application of the design method to a traffic network with thirty-three signalized intersections is used to demonstrate the effectiveness of the proposed technique.

  11. A new traffic control design method for large networks with signalized intersections

    NASA Technical Reports Server (NTRS)

    Leininger, G. G.; Colony, D. C.; Seldner, K.

    1979-01-01

    The paper presents a traffic control design technique for application to large traffic networks with signalized intersections. It is shown that the design method adopts a macroscopic viewpoint to establish a new traffic modelling procedure in which vehicle platoons are subdivided into main stream queues and turning queues. Optimization of the signal splits minimizes queue lengths in the steady state condition and improves traffic flow conditions, from the viewpoint of the traveling public. Finally, an application of the design method to a traffic network with thirty-three signalized intersections is used to demonstrate the effectiveness of the proposed technique.

  12. Integration of Predictive Routing Information with Dynamic Traffic Signal Control

    DTIC Science & Technology

    1994-05-01

    vehicles without the on-board guidance aid (Harris, S., Rabone , A., et.al., 1992). The simulation developed was called ROute GUidance Simulation (ROGUS...Florida. Harris, S., Rabone , A., et.al. 1992. ROGUS: A Simulation of Dynamic Route Guidance Systems. Traffic Engineering and Control(33)327-329

  13. Traffic states and fundamental diagram in cellular automaton model of vehicular traffic controlled by signals

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2009-04-01

    We present a cellular automaton (CA) model for vehicular traffic controlled by traffic lights. The CA model is not described by a set of rules, but is given by a simple difference equation. The vehicular motion varies highly with both signals’ characteristics and vehicular density. The dependence of tour time on both cycle time and vehicular density is clarified. In the dilute limit of vehicles, the vehicular motion is compared with that by the nonlinear-map model. The fundamental diagrams are derived numerically. It is shown that the fundamental diagram depends highly on the signals’ characteristics. The traffic states are shown for various values of cycle time in the fundamental diagram. We also study the effect of a slow vehicle on the traffic flow.

  14. Effects of speed bottleneck on traffic flow with feedback control signal

    NASA Astrophysics Data System (ADS)

    Zhu, Kangli; Bi, Jiantao; Wu, Jianjun; Li, Shubin

    2016-09-01

    Various car-following models (CMs) have been developed to capture the complex characteristics of microscopic traffic flow, among which the coupled map CM can better reveal and reflect various phenomena of practical traffic flow. Capacity change at bottleneck contributes to high-density traffic flow upstream the bottleneck and contains very complex dynamic behavior. In this paper, we analyze the effect of speed bottleneck on the spatial-temporal evolution characteristics of traffic flow, and propose a method to reduce traffic congestion with the feedback control signal based on CM. Simulation results highlight the potential of using the feedback signal to control the stop-and-go wave and furthermore to alleviate the traffic congestion effectively.

  15. Advanced interactive display formats for terminal area traffic control

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.

    1995-01-01

    The basic design considerations for perspective Air Traffic Control displays are described. A software framework has been developed for manual viewing parameter setting (MVPS) in preparation for continued, ongoing developments on automated viewing parameter setting (AVPS) schemes. The MVPS system is based on indirect manipulation of the viewing parameters. Requests for changes in viewing parameter setting are entered manually by the operator by moving viewing parameter manipulation pointers on the screen. The motion of these pointers, which are an integral part of the 3-D scene, is limited to the boundaries of screen. This arrangement has been chosen, in order to preserve the correspondence between the new and the old viewing parameter setting, a feature which contributes to preventing spatial disorientation of the operator. For all viewing operations, e.g. rotation, translation and ranging, the actual change is executed automatically by the system, through gradual transitions with an exponentially damped, sinusoidal velocity profile, in this work referred to as 'slewing' motions. The slewing functions, which eliminate discontinuities in the viewing parameter changes, are designed primarily for enhancing the operator's impression that he, or she, is dealing with an actually existing physical system, rather than an abstract computer generated scene. Current, ongoing efforts deal with the development of automated viewing parameter setting schemes. These schemes employ an optimization strategy, aimed at identifying the best possible vantage point, from which the Air Traffic Control scene can be viewed, for a given traffic situation.

  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. 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.

  18. Distributed input/output subsystem for traffic signal control. Final report, December 1993-May 1995

    SciTech Connect

    Bullock, D.; Schwem, C.

    1995-07-01

    The `distributed input/output sybsystem` is an electrical interface between a traffic device controller, its sensors (typically loop detectors), and its actuators (typically signal lamps), Spread-spectrum signals from the controller are carried over a pair of 110VAC wires that supply power to the devices. Control modules at the actuators decode these signals and implement only the commands that are addressed to their devices. The process also works in reverse for sensors, using the same hardware elements. This interface greatly reduces the quantity of wiring installed at traffic signals and can be easily expanded to accommodate additional sensors and actuators. This can substantially reduce labor and material costs. This project demonstrated distributed control modules for several ITS applications: traffic signal lamps, ramp meters, loop detectors and variable message signs.

  19. Advanced Interactive Display formats for Terminal Area Traffic Control

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.

    1999-01-01

    This report describes the basic design considerations for perspective Air Traffic Control displays. A software framework has been developed for manual viewing parameter setting (MVPS) in preparation for continued, ongoing developments on automated viewing parameter setting (AVPS) schemes. Two distinct modes of MVPS operations are considered, both of which utilize manipulation pointers imbedded in the three-dimensional scene: (1) direct manipulation of the viewing parameters; in this mode the manipulation pointers act like the control-input device, through which the viewing parameter changes are made. Part of the parameters are rate controlled, and part of them position controlled. This mode is intended for making fast, iterative small changes in the parameters. (2) indirect manipulation of the viewing parameters. This mode is intended primarily for introducing large, predetermined changes in the parameters. Requests for changes in viewing parameter setting are entered manually by the operator by moving viewing parameter manipulation pointers on the screen. The motion of these pointers, which are an integral part of the 3-D scene, is limited to the boundaries of screen. This arrangement has been chosen, in order to preserve the correspondence between the spatial lay-outs of the new and the old viewing parameter setting, a feature which contributes to preventing spatial disorientation of the operator. For all viewing operations, e.g. rotation, translation and ranging, the actual change is executed automatically by the system, through gradual transitions with an exponentially damped, sinusoidal velocity profile, in this work referred to as 'slewing' motions. The slewing functions, which eliminate discontinuities in the viewing parameter changes, are designed primarily for enhancing the operator's impression that he, or she, is dealing with an actually existing physical system, rather than an abstract computer-generated scene, The proposed, continued research efforts

  20. Advanced interactive display formats for terminal area traffic control

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.

    1996-01-01

    This report describes the basic design considerations for perspective air traffic control displays. A software framework has been developed for manual viewing parameter setting (MVPS) in preparation for continued, ongoing developments on automated viewing parameter setting (AVPS) schemes. Two distinct modes of MVPS operations are considered, both of which utilize manipulation pointers imbedded in the three-dimensional scene: (1) direct manipulation of the viewing parameters -- in this mode the manipulation pointers act like the control-input device, through which the viewing parameter changes are made. Part of the parameters are rate controlled, and part of them position controlled. This mode is intended for making fast, iterative small changes in the parameters. (2) Indirect manipulation of the viewing parameters -- this mode is intended primarily for introducing large, predetermined changes in the parameters. Requests for changes in viewing parameter setting are entered manually by the operator by moving viewing parameter manipulation pointers on the screen. The motion of these pointers, which are an integral part of the 3-D scene, is limited to the boundaries of the screen. This arrangement has been chosen in order to preserve the correspondence between the spatial lay-outs of the new and the old viewing parameter setting, a feature which contributes to preventing spatial disorientation of the operator. For all viewing operations, e.g. rotation, translation and ranging, the actual change is executed automatically by the system, through gradual transitions with an exponentially damped, sinusoidal velocity profile, in this work referred to as 'slewing' motions. The slewing functions, which eliminate discontinuities in the viewing parameter changes, are designed primarily for enhancing the operator's impression that he, or she, is dealing with an actually existing physical system, rather than an abstract computer-generated scene. The proposed, continued research

  1. Cellular metabolic and autophagic pathways: traffic control by redox signaling.

    PubMed

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-10-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Cellular Metabolic and Autophagic Pathways: Traffic Control by Redox Signaling

    PubMed Central

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-01-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality, and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function. PMID:23702245

  3. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems. The...

  4. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... standards applicable to traffic control systems. 236.401 Section 236.401 Transportation Other Regulations... TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems. The...

  5. Research and design of intelligent distributed traffic signal light control system based on CAN bus

    NASA Astrophysics Data System (ADS)

    Chen, Yu

    2007-12-01

    Intelligent distributed traffic signal light control system was designed based on technologies of infrared, CAN bus, single chip microprocessor (SCM), etc. The traffic flow signal is processed with the core of SCM AT89C51. At the same time, the SCM controls the CAN bus controller SJA1000/transceiver PCA82C250 to build a CAN bus communication system to transmit data. Moreover, up PC realizes to connect and communicate with SCM through USBCAN chip PDIUSBD12. The distributed traffic signal light control system with three control styles of Vehicle flux, remote and PC is designed. This paper introduces the system composition method and parts of hardware/software design in detail.

  6. Overcoming the Pigou-Downs Paradox Using Advanced Traffic Signal Control

    NASA Astrophysics Data System (ADS)

    Fowdur, S. C.; Rughooputh, S. D. D. V.

    2013-06-01

    Expansion of a road network has often been observed to cause more congestion and has led researchers to the formulation of traffic paradoxes such as the Pigou-Downs and the Braess paradoxes. In this paper, we present an application of advanced traffic signal control (ATSC) to overcome the Pigou-Downs paradox. Port Louis, the capital city of Mauritius is used to investigate the effect of using a harbor bridge to by-pass the city center. Using traffic cellular automata (TCA) simulations it has been shown how, if traffic is only gradually deviated along the by-pass, an overall longer travel time and decreased flux would result. By making use of ATSC, which involves traffic lights that sense the number of vehicles accumulated in the queue, better travel times and fluxes are achieved.

  7. A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy.

    PubMed

    Bie, Yiming; Liu, Zhiyuan; Wang, Yinhai

    2017-01-01

    To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios.

  8. A real-time traffic control method for the intersection with pre-signals under the phase swap sorting strategy

    PubMed Central

    Bie, Yiming; Wang, Yinhai

    2017-01-01

    To deal with the conflicts between left-turn and through traffic streams and increase the discharge capacity, this paper addresses the pre-signal which is implemented at a signalized intersection. Such an intersection with pre-signal is termed as a tandem intersection. For the tandem intersection, phase swap sorting strategy is deemed as the most effective phasing scheme in view of some exclusive merits, such as easier compliance of drivers, and shorter sorting area. However, a major limitation of the phase swap sorting strategy is not considered in previous studies: if one or more vehicle is left at the sorting area after the signal light turns to red, the capacity of the approach would be dramatically dropped. Besides, previous signal control studies deal with a fixed timing plan that is not adaptive with the fluctuation of traffic flows. Therefore, to cope with these two gaps, this paper firstly takes an in-depth analysis of the traffic flow operations at the tandem intersection. Secondly, three groups of loop detectors are placed to obtain the real-time vehicle information for adaptive signalization. The lane selection behavior in the sorting area is considered to set the green time for intersection signals. With the objective of minimizing the vehicle delay, the signal control parameters are then optimized based on a dynamic programming method. Finally, numerical experiments show that average vehicle delay and maximum queue length can be reduced under all scenarios. PMID:28531198

  9. From Cellular Attractor Selection to Adaptive Signal Control for Traffic Networks.

    PubMed

    Tian, Daxin; Zhou, Jianshan; Sheng, Zhengguo; Wang, Yunpeng; Ma, Jianming

    2016-03-14

    The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains.

  10. From Cellular Attractor Selection to Adaptive Signal Control for Traffic Networks

    NASA Astrophysics Data System (ADS)

    Tian, Daxin; Zhou, Jianshan; Sheng, Zhengguo; Wang, Yunpeng; Ma, Jianming

    2016-03-01

    The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains.

  11. From Cellular Attractor Selection to Adaptive Signal Control for Traffic Networks

    PubMed Central

    Tian, Daxin; Zhou, Jianshan; Sheng, Zhengguo; Wang, Yunpeng; Ma, Jianming

    2016-01-01

    The management of varying traffic flows essentially depends on signal controls at intersections. However, design an optimal control that considers the dynamic nature of a traffic network and coordinates all intersections simultaneously in a centralized manner is computationally challenging. Inspired by the stable gene expressions of Escherichia coli in response to environmental changes, we explore the robustness and adaptability performance of signalized intersections by incorporating a biological mechanism in their control policies, specifically, the evolution of each intersection is induced by the dynamics governing an adaptive attractor selection in cells. We employ a mathematical model to capture such biological attractor selection and derive a generic, adaptive and distributed control algorithm which is capable of dynamically adapting signal operations for the entire dynamical traffic network. We show that the proposed scheme based on attractor selection can not only promote the balance of traffic loads on each link of the network but also allows the global network to accommodate dynamical traffic demands. Our work demonstrates the potential of bio-inspired intelligence emerging from cells and provides a deep understanding of adaptive attractor selection-based control formation that is useful to support the designs of adaptive optimization and control in other domains. PMID:26972968

  12. Vehicular motion in counter traffic flow through a series of signals controlled by a phase shift

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi; Tobita, Kazuhiro

    2012-10-01

    We study the dynamical behavior of counter traffic flow through a sequence of signals (traffic lights) controlled by a phase shift. There are two lanes for the counter traffic flow: the first lane is for east-bound vehicles and the second lane is for west-bound vehicles. The green-wave strategy is studied in the counter traffic flow where the phase shift of signals in the second lane has opposite sign to that in the first lane. A nonlinear dynamic model of the vehicular motion is presented by nonlinear maps at a low density. There is a distinct difference between the traffic flow in the first lane and that in the second lane. The counter traffic flow exhibits very complex behavior on varying the cycle time, the phase difference, and the split. Also, the fundamental diagram is derived by the use of the cellular automaton (CA) model. The dependence of east-bound and west-bound vehicles on cycle time, phase difference, and density is clarified.

  13. Multiobjective Reinforcement Learning for Traffic Signal Control Using Vehicular Ad Hoc Network

    NASA Astrophysics Data System (ADS)

    Houli, Duan; Zhiheng, Li; Yi, Zhang

    2010-12-01

    We propose a new multiobjective control algorithm based on reinforcement learning for urban traffic signal control, named multi-RL. A multiagent structure is used to describe the traffic system. A vehicular ad hoc network is used for the data exchange among agents. A reinforcement learning algorithm is applied to predict the overall value of the optimization objective given vehicles' states. The policy which minimizes the cumulative value of the optimization objective is regarded as the optimal one. In order to make the method adaptive to various traffic conditions, we also introduce a multiobjective control scheme in which the optimization objective is selected adaptively to real-time traffic states. The optimization objectives include the vehicle stops, the average waiting time, and the maximum queue length of the next intersection. In addition, we also accommodate a priority control to the buses and the emergency vehicles through our model. The simulation results indicated that our algorithm could perform more efficiently than traditional traffic light control methods.

  14. Air Traffic Controllers' Control Strategies in the Terminal Area Under Off-Nominal Conditions

    NASA Technical Reports Server (NTRS)

    Martin, Lynne; Mercer, Joey; Callantine, Todd; Kupfer, Michael; Cabrall, Christopher

    2012-01-01

    A human-in-the-loop simulation investigated the robustness of a schedule-based terminal-area air traffic management concept, and its supporting controller tools, to off-nominal events - events that led to situations in which runway arrival schedules required adjustments and controllers could no longer use speed control alone to impose the necessary delays. The main research question was exploratory: to assess whether controllers could safely resolve and control the traffic during off-nominal events. A focus was the role of the supervisor - how he managed the schedules, how he assisted the controllers, what strategies he used, and which combinations of tools he used. Observations and questionnaire responses revealed supervisor strategies for resolving events followed a similar pattern: a standard approach specific to each type of event often resolved to a smooth conclusion. However, due to the range of factors influencing the event (e.g., environmental conditions, aircraft density on the schedule, etc.), sometimes the plan required revision and actions had a wide-ranging effect.

  15. Air Traffic Control Radar

    NASA Image and Video Library

    2003-08-13

    An Air Traffic Control radar has been constructed at Shiloh for the NASA control tower at the Shuttle Landing Facility. It will be used by NASA and the Eastern Range for surveillance of controlled air space in Kennedy Space Center and Cape Canaveral Air Force Station restricted areas. Shiloh is on the northern end of Merritt Island.

  16. Air Traffic Control Radar

    NASA Image and Video Library

    2003-08-13

    An Air Traffic Control radar is being constructed at Shiloh for the NASA control tower at the Shuttle Landing Facility. It will be used by NASA and the Eastern Range for surveillance of controlled air space in Kennedy Space Center and Cape Canaveral Air Force Station restricted areas. Shiloh is on the northern end of Merritt Island.

  17. An RFID-based intelligent vehicle speed controller using active traffic signals.

    PubMed

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver's attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

  18. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    PubMed Central

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

  19. On optimal scheduling and air traffic control in the near terminal area. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Sarris, A. H.

    1971-01-01

    A scheme is proposed for automated air traffic control of landing aircraft in the vicinity of the airport. Each aircraft is put under the control of an airport-based computer as soon as it enters the near-terminal area (NTA). Scheduling is done immediately thereafter. The aircraft is given a flight plan which, if followed precisely, will lead it to the runway at a prespecified time. The geometry of the airspace in the NTA is chosen so that delays are executed far from the outer marker, and violations of minimum altitude and lateral separations are avoided. Finally, a solution to the velocity mix problem is proposed.

  20. 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.

  1. Analysis of the work of air traffic controllers of the approach control area (APP) of Porto Alegre, Brazil.

    PubMed

    Vargas, C V; Guimarães, L B de M; Sant'Anna, A M O

    2012-01-01

    This article presents a study on the activities of the air traffic controllers of the Approach Control Area (APP) of Porto Alegre, Brazil, in different real scenarios. Based on interviews, questionnaires and the analysis of film of real scenes, the following were identified and analyzed: i) the perceptions of risk and complexity of the different air traffic scenes observed; ii) the cognitive factors (knowledge, strategy and attention dynamics) involved in the task and iii) the perception of the controller's workload. The results showed that the task complexity depends on the weather conditions, the number and type of aircraft in observation and that the controllers perceive the scenes in a similar way irrespective of their time in the profession and the type of control (radar or coordination). Attention is the cognitive factor with the greatest impact on the work and mental demand has the greatest impact on workload followed by time demand. The literature on the controllers work in Brazil is scarce and, therefore, this study aimed to contribute to the understanding of the work in one APP in order to promote future changes in the very problematic Brazilian air traffic system.

  2. TraPy-MAC: Traffic Priority Aware Medium Access Control Protocol for Wireless Body Area Network.

    PubMed

    Ullah, Fasee; Abdullah, Abdul Hanan; Kaiwartya, Omprakash; Cao, Yue

    2017-06-01

    Recently, Wireless Body Area Network (WBAN) has witnessed significant attentions in research and product development due to the growing number of sensor-based applications in healthcare domain. Design of efficient and effective Medium Access Control (MAC) protocol is one of the fundamental research themes in WBAN. Static on-demand slot allocation to patient data is the main approach adopted in the design of MAC protocol in literature, without considering the type of patient data specifically the level of severity on patient data. This leads to the degradation of the performance of MAC protocols considering effectiveness and traffic adjustability in realistic medical environments. In this context, this paper proposes a Traffic Priority-Aware MAC (TraPy-MAC) protocol for WBAN. It classifies patient data into emergency and non-emergency categories based on the severity of patient data. The threshold value aided classification considers a number of parameters including type of sensor, body placement location, and data transmission time for allocating dedicated slots patient data. Emergency data are not required to carry out contention and slots are allocated by giving the due importance to threshold value of vital sign data. The contention for slots is made efficient in case of non-emergency data considering threshold value in slot allocation. Moreover, the slot allocation to emergency and non-emergency data are performed parallel resulting in performance gain in channel assignment. Two algorithms namely, Detection of Severity on Vital Sign data (DSVS), and ETS Slots allocation based on the Severity on Vital Sign (ETS-SVS) are developed for calculating threshold value and resolving the conflicts of channel assignment, respectively. Simulations are performed in ns2 and results are compared with the state-of-the-art MAC techniques. Analysis of results attests the benefit of TraPy-MAC in comparison with the state-of-the-art MAC in channel assignment in realistic medical

  3. Supervised learning from human performance at the computationally hard problem of optimal traffic signal control on a network of junctions

    PubMed Central

    Box, Simon

    2014-01-01

    Optimal switching of traffic lights on a network of junctions is a computationally intractable problem. In this research, road traffic networks containing signallized junctions are simulated. A computer game interface is used to enable a human ‘player’ to control the traffic light settings on the junctions within the simulation. A supervised learning approach, based on simple neural network classifiers can be used to capture human player's strategies in the game and thus develop a human-trained machine control (HuTMaC) system that approaches human levels of performance. Experiments conducted within the simulation compare the performance of HuTMaC to two well-established traffic-responsive control systems that are widely deployed in the developed world and also to a temporal difference learning-based control method. In all experiments, HuTMaC outperforms the other control methods in terms of average delay and variance over delay. The conclusion is that these results add weight to the suggestion that HuTMaC may be a viable alternative, or supplemental method, to approximate optimization for some practical engineering control problems where the optimal strategy is computationally intractable. PMID:26064570

  4. CTAS: Computer intelligence for air traffic control in the terminal area

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    1992-01-01

    A system for the automated management and control of arrival traffic, referred to as the Center-TRACON Automation System (CTAS), has been designed by the ATC research group at NASA Ames research center. In a cooperative program, NASA and the FAA have efforts underway to install and evaluate the system at the Denver and Dallas/Ft. Worth airports. CTAS consists of three types of integrated tools that provide computer-generated intelligence for both Center and TRACON controllers to guide them in managing and controlling arrival traffic efficiently. One tool, the Traffic Management Advisor (TMA), establishes optimized landing sequences and landing times for aircraft arriving in the center airspace several hundred miles from the airport. In TRACON, TMA frequencies missed approach aircraft and unanticipated arrivals. Another tool, the Descent Advisor (DA), generates clearances for the center controllers handling at crossing times provided by TMA. In the TRACON, the final approach spacing tool (FAST) provides heading and speed clearances that produce and accurately spaced flow of aircraft on the final approach course. A data base consisting of aircraft performance models, airline preferred operational procedures and real time wind measurements contribute to the effective operation of CTAS. Extensive simulator evaluations of CTAS have demonstrated controller acceptance, delay reductions, and fuel savings.

  5. Traffic signals and depth perception.

    PubMed

    Bugelski, B R

    1967-09-22

    Automobiles approaching red traffic signals at night appear to go beyond them when viewed from some distance to the rear. The phenomenon is doubly illusory because the higher of two objects has been presumed to appear more distant. The illusion is probably limited to small visual angles (about 2 degrees).

  6. Traffic dispersion through a series of signals with irregular split

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2016-01-01

    We study the traffic behavior of a group of vehicles moving through a sequence of signals with irregular splits on a roadway. We present the stochastic model of vehicular traffic controlled by signals. The dynamic behavior of vehicular traffic is clarified by analyzing traffic pattern and travel time numerically. The group of vehicles breaks up more and more by the irregularity of signal's split. The traffic dispersion is induced by the irregular split. We show that the traffic dispersion depends highly on the cycle time and the strength of split's irregularity. Also, we study the traffic behavior through the series of signals at the green-wave strategy. The dependence of the travel time on offset time is derived for various values of cycle time. The region map of the traffic dispersion is shown in (cycle time, offset time)-space.

  7. Air Traffic Control Technology

    NASA Technical Reports Server (NTRS)

    Denery, Dallas; Lebacqz, Victor (Technical Monitor)

    1997-01-01

    The steady growth in air travel will lead to heightened demands for additional airspace capacity, particularly in the vicinity of terminals. New computer-aided processing of aircraft and navigational capability exemplified by the Global Positioning System will allow more sophisticated management of air traffic. Additional altitudes and over-flight areas may be necessary to effectively use the newer technology,

  8. 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.

  9. Metropolitan Orlando area computerized signal system

    SciTech Connect

    Aleman, F.R. ); Allen, T.M. )

    1990-06-01

    Florida's Orlando metropolitan area, which has a population measuring 1 million, is among the fastest growing areas in the nation. The city's weather and popular attractions draw 9 to 10 million tourists annually, half of them arriving in their own cars. Add to this the 1.1 million automobiles already on the streets, and the traffic problems become a nightmare. The Orlando metropolitan area has approximately 550 operational traffic signals, with an increasing number of new signals added each year to control the city's expanding growth. A central, computerized signal system has been conceived as one of the solutions necessary to cope with this tremendous traffic growth. The system is flexible, expandable, and capable of meeting future technical challenges. This article describes the steps that led to the feasibility study, design, and implementation of the Orlando area computerized signal system.

  10. 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.

  11. Prospective memory in an air traffic control simulation: External aids that signal when to act

    PubMed Central

    Loft, Shayne; Smith, Rebekah E.; Bhaskara, Adella

    2011-01-01

    At work and in our personal life we often need to remember to perform intended actions at some point in the future, referred to as Prospective Memory. Individuals sometimes forget to perform intentions in safety-critical work contexts. Holding intentions can also interfere with ongoing tasks. We applied theories and methods from the experimental literature to test the effectiveness of external aids in reducing prospective memory error and costs to ongoing tasks in an air traffic control simulation. Participants were trained to accept and hand-off aircraft, and to detect aircraft conflicts. For the prospective memory task participants were required to substitute alternative actions for routine actions when accepting target aircraft. Across two experiments, external display aids were provided that presented the details of target aircraft and associated intended actions. We predicted that aids would only be effective if they provided information that was diagnostic of target occurrence and in this study we examined the utility of aids that directly cued participants when to allocate attention to the prospective memory task. When aids were set to flash when the prospective memory target aircraft needed to be accepted, prospective memory error and costs to ongoing tasks of aircraft acceptance and conflict detection were reduced. In contrast, aids that did not alert participants specifically when the target aircraft were present provided no advantage compared to when no aids we used. These findings have practical implications for the potential relative utility of automated external aids for occupations where individuals monitor multi-item dynamic displays. PMID:21443381

  12. An ultra low-power and traffic-adaptive medium access control protocol for wireless body area network.

    PubMed

    Ullah, Sana; Kwak, Kyung Sup

    2012-06-01

    Wireless Body Area Network (WBAN) consists of low-power, miniaturized, and autonomous wireless sensor nodes that enable physicians to remotely monitor vital signs of patients and provide real-time feedback with medical diagnosis and consultations. It is the most reliable and cheaper way to take care of patients suffering from chronic diseases such as asthma, diabetes and cardiovascular diseases. Some of the most important attributes of WBAN is low-power consumption and delay. This can be achieved by introducing flexible duty cycling techniques on the energy constraint sensor nodes. Stated otherwise, low duty cycle nodes should not receive frequent synchronization and control packets if they have no data to send/receive. In this paper, we introduce a Traffic-adaptive MAC protocol (TaMAC) by taking into account the traffic information of the sensor nodes. The protocol dynamically adjusts the duty cycle of the sensor nodes according to their traffic-patterns, thus solving the idle listening and overhearing problems. The traffic-patterns of all sensor nodes are organized and maintained by the coordinator. The TaMAC protocol is supported by a wakeup radio that is used to accommodate emergency and on-demand events in a reliable manner. The wakeup radio uses a separate control channel along with the data channel and therefore it has considerably low power consumption requirements. Analytical expressions are derived to analyze and compare the performance of the TaMAC protocol with the well-known beacon-enabled IEEE 802.15.4 MAC, WiseMAC, and SMAC protocols. The analytical derivations are further validated by simulation results. It is shown that the TaMAC protocol outperforms all other protocols in terms of power consumption and delay.

  13. Seven Traffic Signals in Two Minutes

    SciTech Connect

    2011-01-01

    Topeka, KS has activated the first of three key traffic corridors to receive a "green light tunnel," a real-time adaptive traffic signal system that synchronizes signals to create a series of green lights for motorists. The result is fewer stops, less travel time and -- most importantly -- a lot of saved gasoline.

  14. Chaotic Ising-like dynamics in traffic signals

    PubMed Central

    Suzuki, Hideyuki; Imura, Jun-ichi; Aihara, Kazuyuki

    2013-01-01

    The green and red lights of a traffic signal can be viewed as the up and down states of an Ising spin. Moreover, traffic signals in a city interact with each other, if they are controlled in a decentralised way. In this paper, a simple model of such interacting signals on a finite-size two-dimensional lattice is shown to have Ising-like dynamics that undergoes a ferromagnetic phase transition. Probabilistic behaviour of the model is realised by chaotic billiard dynamics that arises from coupled non-chaotic elements. This purely deterministic model is expected to serve as a starting point for considering statistical mechanics of traffic signals. PMID:23350034

  15. Remotely-Operated Traffic Control Light

    NASA Technical Reports Server (NTRS)

    Reedy, J. S.

    1984-01-01

    Traffic warning light for school crossing, construction zones, and other hazardous areas activated by remote control. Apparatus consists of small radio transmitter, pole-mounted strobe light with attached power supply and radio receiver.

  16. Intelligent traffic control system using PLC

    NASA Astrophysics Data System (ADS)

    Barz, C.; Todea, C.; Latinovic, T.; Preradovic, D. M.; Deaconu, S.; Berdie, A.

    2016-08-01

    The paper presents the traffic control system controlled through a PLC which takes the signals from different sensors on roads. The global system developed ensures the coordination of four intersections, setting a path that respects coordination type green light, the integration of additional sensors, the implementation of probes radar to inform traffic participants about recommended speed for accessing the green state located in the intersection that will follow to cross.

  17. 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.

  18. Development and investigation of a pollution control pit for treatment of stormwater from metal roofs and traffic areas.

    PubMed

    Dierkes, C; Göbel, P; Lohmann, M; Coldewey, W G

    2006-01-01

    Source control by on-site retention and infiltration of stormwater is a sustainable and proven alternative to classical drainage methods. Unfortunately, sedimentary particles and pollutants from drained surfaces cause clogging and endanger soil and groundwater during long-term operation of infiltration devices. German water authorities recommend the use of infiltration devices, such as swales or swale-trench-systems. Direct infiltration by underground facilities, such as pipes, trenches or sinks, without pretreatment of runoff is generally not permitted. Problems occur with runoff from metal roofs, traffic areas and industrial sites. However, due to site limitations, underground systems are often the only feasible option. To overcome this situation, a pollution control pit was developed with a hydrodynamic separator and a multistage filter made of coated porous concrete. The system treats runoff at source and protects soil, groundwater and receiving waterways. Typically, more than 90% of the pollutants such as sedimentary particles, hydrocarbons and heavy metals can be removed. Filters have been developed to treat even higher polluted stormwater loads from metal roofs and industrial sites. The treatment process is based on sedimentation, filtration, adsorption and chemical precipitation. Sediments are trapped in a special chamber within the pit and can be removed easily. Other pollutants are captured in the concrete filter upstream of the sediment separator chamber. Filters can be easily replaced.

  19. Broadcast control of air traffic

    NASA Technical Reports Server (NTRS)

    Litchford, G. B.

    1971-01-01

    Concepts of increased pilot participation in air traffic control are presented. The design of an air traffic control system for pilot usage is considered. The operating and safety benefits of LF/VLF approaches in comparison to current nonprecision approach procedures and systems are discussed. With a good national system plan, flight testing and validation, and the use of local differential, or general diurnal, corrections, the LF/VLF system would provide service superior to that presently available.

  20. 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.

  1. Design and Construction of Intelligent Traffic Light Control System Using Fuzzy Logic

    NASA Astrophysics Data System (ADS)

    Lin, Htin; Aye, Khin Muyar; Tun, Hla Myo; Theingi, Naing, Zaw Min

    2008-10-01

    Vehicular travel is increasing throughout the world, particularly in large urban areas. Therefore the need arises for simulation and optimizing traffic control algorithms to better accommodate this increasing demand. This paper presents a microcontroller simulation of intelligent traffic light controller using fuzzy logic that is used to change the traffic signal cycles adaptively at a two-way intersection. This paper is an attempt to design an intelligent traffic light control systems using microcontrollers such as PIC 16F84A and PIC 16F877A. And then traffic signal can be controlled depending upon the densities of cars behind green and red lights of the two-way intersection by using sensors and detectors circuits.

  2. Sunglasses, traffic signals, and color vision deficiencies.

    PubMed

    Dain, Stephen J; Wood, Joanne M; Atchison, David A

    2009-04-01

    To determine (a) the effect of different sunglass tint colorations on traffic signal detection and recognition for color normal and color deficient observers, and (b) the adequacy of coloration requirements in current sunglass standards. Twenty color-normals and 49 color-deficient males performed a tracking task while wearing sunglasses of different colorations (clear, gray, green, yellow-green, yellow-brown, red-brown). At random intervals, simulated traffic light signals were presented against a white background at 5 degrees to the right or left and observers were instructed to identify signal color (red/yellow/green) by pressing a response button as quickly as possible; response times and response errors were recorded. Signal color and sunglass tint had significant effects on response times and error rates (p < 0.05), with significant between-color group differences and interaction effects. Response times for color deficient people were considerably slower than color normals for both red and yellow signals for all sunglass tints, but for green signals they were only noticeably slower with the green and yellow-green lenses. For most of the color deficient groups, there were recognition errors for yellow signals combined with the yellow-green and green tints. In addition, deuteranopes had problems for red signals combined with red-brown and yellow-brown tints, and protanopes had problems for green signals combined with the green tint and for red signals combined with the red-brown tint. Many sunglass tints currently permitted for drivers and riders cause a measurable decrement in the ability of color deficient observers to detect and recognize traffic signals. In general, combinations of signals and sunglasses of similar colors are of particular concern. This is prima facie evidence of a risk in the use of these tints for driving and cautions against the relaxation of coloration limits in sunglasses beyond those represented in the study.

  3. 49 CFR 236.405 - Track signaled for movements in both directions, change of direction of traffic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.405 Track signaled for...

  4. LED traffic lights: New technology signals major energy savings

    SciTech Connect

    Houghton, D.

    1994-12-31

    Using light-emitting diode technology to replace incandescent lamps in traffic signals promises energy savings upwards of 60 percent for each of the estimated quarter of a million controlled intersections in the United States. LED units use only 9 to 25 watts instead of the 67 to 150 watts used by each incandescent lamp. Though their first cost is relatively high, energy savings result in paybacks of 1 to 5 years. LED retrofit kits are available for red signal disks and arrows, and installations in several states have proven successful, although minor improvements are addressing concerns about varying light output and controller circuitry. Retrofitting green lamps is not yet feasible, because color standards of the Institute of Traffic Engineers cannot be met with existing LED technology. Yellow lamps have such low duty factors (they`re on only 3 percent of the time) that retrofitting with LED signals is not cost-effective. LEDs last much longer than incandescents, allowing municipalities to not only reduce their electricity bills, but to save on maintenance costs as well. As further incentive, some utilities are beginning to implement rebate programs for LED traffic signal retrofits. Full approval of LED units is still awaited from the Institute of Traffic Engineers (ITE), the standard-setting body for traffic safety devices. Local and state governments ultimately decide what specifications to require for traffic lights, and the growing body of successful field experience with LEDs appears to be raising their comfort level with the technology. The California Department of Transportation is developing an LED traffic light specification, and two California utilities, Southern California Edison and Pacific Gas and Electric, have provided rebates for some pilot installations.

  5. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  6. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Traffic signal synchronization..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  7. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Traffic signal synchronization projects..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic signal synchronization projects. Traffic signal synchronization projects may be approved, funded, and implemented without...

  8. 49 CFR 236.828 - System, traffic control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false System, traffic control. 236.828 Section 236.828 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... System, traffic control. A block signal system under which train movements are authorized by...

  9. 49 CFR 236.828 - System, traffic control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false System, traffic control. 236.828 Section 236.828 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... System, traffic control. A block signal system under which train movements are authorized by...

  10. 49 CFR 236.828 - System, traffic control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false System, traffic control. 236.828 Section 236.828 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... System, traffic control. A block signal system under which train movements are authorized by...

  11. 49 CFR 236.828 - System, traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false System, traffic control. 236.828 Section 236.828 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... System, traffic control. A block signal system under which train movements are authorized by...

  12. 49 CFR 236.828 - System, traffic control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false System, traffic control. 236.828 Section 236.828 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... System, traffic control. A block signal system under which train movements are authorized by...

  13. The postsynaptic t-SNARE Syntaxin 4 controls traffic of Neuroligin 1 and Synaptotagmin 4 to regulate retrograde signaling

    PubMed Central

    Harris, Kathryn P; Zhang, Yao V; Piccioli, Zachary D; Perrimon, Norbert; Littleton, J Troy

    2016-01-01

    Postsynaptic cells can induce synaptic plasticity through the release of activity-dependent retrograde signals. We previously described a Ca2+-dependent retrograde signaling pathway mediated by postsynaptic Synaptotagmin 4 (Syt4). To identify proteins involved in postsynaptic exocytosis, we conducted a screen for candidates that disrupted trafficking of a pHluorin-tagged Syt4 at Drosophila neuromuscular junctions (NMJs). Here we characterize one candidate, the postsynaptic t-SNARE Syntaxin 4 (Syx4). Analysis of Syx4 mutants reveals that Syx4 mediates retrograde signaling, modulating the membrane levels of Syt4 and the transsynaptic adhesion protein Neuroligin 1 (Nlg1). Syx4-dependent trafficking regulates synaptic development, including controlling synaptic bouton number and the ability to bud new varicosities in response to acute neuronal stimulation. Genetic interaction experiments demonstrate Syx4, Syt4, and Nlg1 regulate synaptic growth and plasticity through both shared and parallel signaling pathways. Our findings suggest a conserved postsynaptic SNARE machinery controls multiple aspects of retrograde signaling and cargo trafficking within the postsynaptic compartment. DOI: http://dx.doi.org/10.7554/eLife.13881.001 PMID:27223326

  14. Three-phase theory of city traffic: Moving synchronized flow patterns in under-saturated city traffic at signals

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.

    2014-03-01

    Three-phase traffic flow theory of city traffic has been developed. Based on simulations of a stochastic microscopic traffic flow model, features of moving synchronized flow patterns (MSP) have been studied, which are responsible for a random time-delayed breakdown of a green-wave (GW) organized in a city. A possibility of GW control leading to the prevention of GW breakdown has been demonstrated. A diagram of traffic breakdown in under-saturated traffic (transition from under- to over-saturated city traffic) at the signal has been found; the diagram presents regions of the average arrival flow rate, within which traffic breakdown can occur, in dependence of parameters of the time-function of the arrival flow rate or/and signal parameters. Physical reasons for a crucial difference between results of classical theory of city traffic and three-phase theory are explained. In particular, we have found that under-saturated traffic at the signal can exist during a long time interval, when the average arrival flow rate is larger than the capacity of the classical theory; the classical capacity is equal to a minimum capacity in three-phase theory. Within a range of the average arrival flow rate between the minimum and maximum signal capacities, under-saturated traffic is in a metastable state with respect to traffic breakdown. We have distinguished the following possible causes for the metastability of under-saturated traffic: (i) The arrival flow rate during the green phase is larger than the saturation flow rate. (ii) The length of the upstream front of a queue at the signal is a finite value. (iii) The outflow rate from a MSP (the rate of MSP discharge) is larger than the saturation flow rate.

  15. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    PubMed Central

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN. PMID:25663835

  16. Traffic signal synchronization in the saturated high-density grid road network.

    PubMed

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

  17. 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.

  18. 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...

  19. 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...

  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 self-propelled...

  1. 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 self-propelled...

  2. 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 self-propelled...

  3. 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 self-propelled...

  4. 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...

  5. 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...

  6. 30 CFR 57.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Dumping Traffic Safety § 57.9100 Traffic control. To provide for the safe movement of self-propelled... 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...

  7. 30 CFR 56.9100 - Traffic control.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Dumping Traffic Safety § 56.9100 Traffic control. To provide for the safe movement of self-propelled... 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...

  8. 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.

  9. Traffic signal phasing at intersections to improve safety for alcohol-affected pedestrians.

    PubMed

    Lenné, Michael G; Corben, Bruce F; Stephan, Karen

    2007-07-01

    Alcohol-affected pedestrians are among the highest-risk groups involved in pedestrian casualty crashes. This paper investigates the opportunities to use a modified form of traffic signal operation during high-risk periods and at high-risk locations to reduce alcohol-affected pedestrian crashes and the severity of injuries that might otherwise occur. The 'Dwell-on-Red' treatment involves displaying a red traffic signal to all vehicle directions during periods when no vehicular traffic is detected, so that drivers approach high-risk intersections at a lower speed than if a green signal were displayed. Vehicle speed data were collected before and after treatment activation at both a control and treatment site. Speed data were collected both 30 m prior to and at the intersection stop line. The treatment was associated with a reduction in mean vehicle speeds of 3.9 kph (9%) and 11.0 kph (28%) at 30 m and stop line collection points, respectively, and substantial reductions in the proportion of vehicles travelling at threatening speeds with regard to the severity of pedestrian injury. Other important road safety concerns may also benefit from this form of traffic signal modification, and it is recommended that other areas of application be explored, including the other severe trauma categories typically concentrated around signalised intersections.

  10. Emergency vehicle traffic signal preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2011-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a control module for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a priority-code (i.e. Code-3) situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a control module which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection. Real-time communications and operations software allow central and remote monitoring, logging, and command of intersections and vehicles.

  11. Emergency vehicle traffic signal preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2005-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a communications controller for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a Code 3 situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a communications controller which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection.

  12. A Sarsa(λ)-Based Control Model for Real-Time Traffic Light Coordination

    PubMed Central

    Zhu, Fei; Liu, Quan; Fu, Yuchen; Huang, Wei

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ)-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ)-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control. PMID:24592183

  13. A Sarsa(λ)-based control model for real-time traffic light coordination.

    PubMed

    Zhou, Xiaoke; Zhu, Fei; Liu, Quan; Fu, Yuchen; Huang, Wei

    2014-01-01

    Traffic problems often occur due to the traffic demands by the outnumbered vehicles on road. Maximizing traffic flow and minimizing the average waiting time are the goals of intelligent traffic control. Each junction wants to get larger traffic flow. During the course, junctions form a policy of coordination as well as constraints for adjacent junctions to maximize their own interests. A good traffic signal timing policy is helpful to solve the problem. However, as there are so many factors that can affect the traffic control model, it is difficult to find the optimal solution. The disability of traffic light controllers to learn from past experiences caused them to be unable to adaptively fit dynamic changes of traffic flow. Considering dynamic characteristics of the actual traffic environment, reinforcement learning algorithm based traffic control approach can be applied to get optimal scheduling policy. The proposed Sarsa(λ)-based real-time traffic control optimization model can maintain the traffic signal timing policy more effectively. The Sarsa(λ)-based model gains traffic cost of the vehicle, which considers delay time, the number of waiting vehicles, and the integrated saturation from its experiences to learn and determine the optimal actions. The experiment results show an inspiring improvement in traffic control, indicating the proposed model is capable of facilitating real-time dynamic traffic control.

  14. Traffic breakdown at a signal: classical theory versus the three-phase theory of city traffic

    NASA Astrophysics Data System (ADS)

    Kerner, Boris S.; Klenov, Sergey L.; Schreckenberg, Michael

    2014-03-01

    Physical reasons for a crucial difference between the results of a three-phase theory developed recently (Kerner 2011 Phys. Rev. E 84 045102(R); 2013 Europhys. Lett. 102 28010; 2014 Physica A 397 76) and the classical theory are explained. Microscopic characteristics of traffic passing a traffic signal during the green signal phase and their dependence on the duration of the green phase have been found. It turns out that a moving synchronized flow pattern (MSP), which occurs in under-saturated traffic at the signal, causes ‘compression’ of traffic flow: the rate of MSP discharge can be considerably larger than the saturation flow rate of the classical traffic theory of city traffic. This leads to a considerably larger rate of traffic passing the signal in comparison with the saturation flow rate. This effect together with traffic behavior at the upstream queue front explains the metastability of under-saturated traffic with respect to a random time-delayed traffic breakdown.

  15. Modeling the effect of microscopic driving behaviors on Kerner's time-delayed traffic breakdown at traffic signal using cellular automata

    NASA Astrophysics Data System (ADS)

    Wang, Yang; Chen, Yan-Yan

    2016-12-01

    The signalized traffic is considerably complex due to the fact that various driving behaviors have emerged to respond to traffic signals. However, the existing cellular automaton models take the signal-vehicle interactions into account inadequately, resulting in a potential risk that vehicular traffic flow dynamics may not be completely explored. To remedy this defect, this paper proposes a more realistic cellular automaton model by incorporating a number of the driving behaviors typically observed when the vehicles are approaching a traffic light. In particular, the anticipatory behavior proposed in this paper is realized with a perception factor designed by considering the vehicle speed implicitly and the gap to its preceding vehicle explicitly. Numerical simulations have been performed based on a signal controlled road which is partitioned into three sections according to the different reactions of drivers. The effects of microscopic driving behaviors on Kerner's time-delayed traffic breakdown at signal (Kerner 2011, 2013) have been investigated with the assistance of spatiotemporal pattern and trajectory analysis. Furthermore, the contributions of the driving behaviors on the traffic breakdown have been statistically examined. Finally, with the activation of the anticipatory behavior, the influences of the other driving behaviors on the formation of platoon have been investigated in terms of the number of platoons, the averaged platoon size, and the averaged flow rate.

  16. LED traffic signals: A market transformation opportunity assessment

    SciTech Connect

    Suozzo, M.

    1998-12-31

    This report examines the feasibility and appropriateness of market intervention strategies to increase the penetration of LED traffic signals, which offer large energy savings and other benefits relative to existing incandescent traffic signals. It presents the state of the technology and some of the technical challenges that remain. Prepared for the Consortium for Energy Efficiency.

  17. Effect of restart at signals on traffic flow through a series of signals

    NASA Astrophysics Data System (ADS)

    Hino, Yuki; Tobita, Kazuhiro; Nagatani, Takashi

    2013-08-01

    We study the effect of restart at signals on the vehicular traffic controlled by a series of signals. The Nagel-Schreckenberg model (NS model) and Fukui-Ishibashi model (FI model) are applied to the vehicular motion. In the FI model, the step-by-step acceleration is not taken into account but the acceleration effect is included in the NS model. It is shown that the difference between both models results in the restart effect at signals. The extended version of the NS model with signals is formulated by the difference equation. The restart at signals has an effective effect on the traffic flow. The fundamental diagram changes highly by the restart effect. The dependences of mean speed on the cycle time are shown.

  18. Automatic speech recognition in air traffic control

    NASA Technical Reports Server (NTRS)

    Karlsson, Joakim

    1990-01-01

    Automatic Speech Recognition (ASR) technology and its application to the Air Traffic Control system are described. The advantages of applying ASR to Air Traffic Control, as well as criteria for choosing a suitable ASR system are presented. Results from previous research and directions for future work at the Flight Transportation Laboratory are outlined.

  19. Behavior of queues at signalized intersections in heavy traffic

    NASA Technical Reports Server (NTRS)

    Posner, E. C.; Rodemich, E. R.

    1976-01-01

    This paper derives the asymptotic behavior of traffic queues at signalized intersections when the excess of departure capacity over arrivals approaches zero from above. The most interesting result is that the distribution of queue length approaches a negative exponential, with fewer restrictive assumptions than hitherto known. The main improvement results from more precise use of a combinatorial lemma of Spitzer, giving the maximum of the partial sums of a sequence of independent identically distributed random variables, plus some specific constructive probability calculations, many of them involving the Fourier transform. New results are presented on the probability that the queue be below a fixed bound and/or on the probability that the queue be empty. Applications to on-line estimators for real-time traffic control are suggested.

  20. Analysis of vehicular traffic flow in the major areas of Kuala Lumpur utilizing open-traffic

    NASA Astrophysics Data System (ADS)

    Manogaran, Saargunawathy; Ali, Muhammad; Yusof, Kamaludin Mohamad; Suhaili, Ramdhan

    2017-09-01

    Vehicular traffic congestion occurs when a large number of drivers are overcrowded on the road and the traffic flow does not run smoothly. Traffic congestion causes chaos on the road and interruption to daily activities of users. Time consumed on road give lots of negative effects on productivity, social behavior, environmental and cost to economy. Congestion is worsens and leads to havoc during the emergency such as flood, accidents, road maintenance and etc., where behavior of traffic flow is always unpredictable and uncontrollable. Real-time and historical traffic data are critical inputs for most traffic flow analysis applications. Researcher attempt to predict traffic using simulations as there is no exact model of traffic flow exists due to its high complexity. Open Traffic is an open source platform available for traffic data analysis linked to Open Street Map (OSM). This research is aimed to study and understand the Open Traffic platform. The real-time traffic flow pattern in Kuala Lumpur area was successfully been extracted and analyzed using Open Traffic. It was observed that the congestion occurs on every major road in Kuala Lumpur and most of it owes to the offices and the economic and commercial centers during rush hours. At some roads the congestion occurs at night due to the tourism activities.

  1. Real-time network traffic classification technique for wireless local area networks based on compressed sensing

    NASA Astrophysics Data System (ADS)

    Balouchestani, Mohammadreza

    2017-05-01

    Network traffic or data traffic in a Wireless Local Area Network (WLAN) is the amount of network packets moving across a wireless network from each wireless node to another wireless node, which provide the load of sampling in a wireless network. WLAN's Network traffic is the main component for network traffic measurement, network traffic control and simulation. Traffic classification technique is an essential tool for improving the Quality of Service (QoS) in different wireless networks in the complex applications such as local area networks, wireless local area networks, wireless personal area networks, wireless metropolitan area networks, and wide area networks. Network traffic classification is also an essential component in the products for QoS control in different wireless network systems and applications. Classifying network traffic in a WLAN allows to see what kinds of traffic we have in each part of the network, organize the various kinds of network traffic in each path into different classes in each path, and generate network traffic matrix in order to Identify and organize network traffic which is an important key for improving the QoS feature. To achieve effective network traffic classification, Real-time Network Traffic Classification (RNTC) algorithm for WLANs based on Compressed Sensing (CS) is presented in this paper. The fundamental goal of this algorithm is to solve difficult wireless network management problems. The proposed architecture allows reducing False Detection Rate (FDR) to 25% and Packet Delay (PD) to 15 %. The proposed architecture is also increased 10 % accuracy of wireless transmission, which provides a good background for establishing high quality wireless local area networks.

  2. The control method for the multi-phase traffic model

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Cheng, Rong-Jun; Ma, Yan-Qiang; Ge, Hong-Xia

    2016-04-01

    Based on multi-phase car-following model proposed by Nagatani, the control theory method is used to analyze the stability of the model. The optimal velocity function is improved to have more turning points. The original optimal velocity with one turning point shows two-phase traffic, while the improved model with n turning points exhibits n+1 phase traffic. Control signal is added into the model. Numerical simulation is conducted to show the results for the stability of the model with and without control signal.

  3. Vehicular Traffic Flow Controlled by Traffic Light on a Street with Open Boundaries

    NASA Astrophysics Data System (ADS)

    Mhirech, Abdelaziz; Ismaili, Assia Alaoui

    2013-08-01

    The Nagel-Schreckenberg (NS) cellular automata (CA) model for describing the vehicular traffic flow in a street with open boundaries is studied. To control the traffic flow, a traffic signalization light operating for a fixed-time scheme is placed in the middle of the street. Extensive Monte Carlo simulations are carried out to calculate various model characteristics. Essentially, we investigate the formation of the cars queue behind traffic light dependence on the duration of green light Tg, injecting and extracting probabilities α and β, respectively. Two phases of average training queues were found. Besides, the dependence of car accident probability per site and per time step on Tg, α and β is computed.

  4. 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.

  5. 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.

  6. Delay-feedback control strategy for reducing CO2 emission of traffic flow system

    NASA Astrophysics Data System (ADS)

    Zhang, Li-Dong; Zhu, Wen-Xing

    2015-06-01

    To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

  7. Collegiate Aviation and FAA Air Traffic Control.

    ERIC Educational Resources Information Center

    Ruiz, Jose R.; Ruiz, Lorelei E.

    2003-01-01

    Based on a literature review this article describes the Air Traffic-Collegiate Training Initiative (AT-CTI) program, including objectives, the process by which postsecondary institutes become affiliated, advantages of affiliation, and the recruitment and employment of air traffic control graduates by the Federal Aviation Administration. (Contains…

  8. Holiday Perspectives on Air Traffic Control

    NASA Image and Video Library

    2016-12-14

    As America travels over the holidays, NASA’s FutureFlight Central (FFC) is working to help passengers get to their destinations on time. The 360-degree virtual air traffic control tower is capable of simulating traffic and weather conditions to include snow, sleet and rain at almost any airport in the United States.

  9. Collegiate Aviation and FAA Air Traffic Control.

    ERIC Educational Resources Information Center

    Ruiz, Jose R.; Ruiz, Lorelei E.

    2003-01-01

    Based on a literature review this article describes the Air Traffic-Collegiate Training Initiative (AT-CTI) program, including objectives, the process by which postsecondary institutes become affiliated, advantages of affiliation, and the recruitment and employment of air traffic control graduates by the Federal Aviation Administration. (Contains…

  10. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Traffic signal synchronization projects. 93.128 Section 93.128 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic...

  11. 40 CFR 93.128 - Traffic signal synchronization projects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Traffic signal synchronization projects. 93.128 Section 93.128 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR..., Funded or Approved Under Title 23 U.S.C. or the Federal Transit Laws § 93.128 Traffic...

  12. City of Phildelphia: Light emitting diodes for traffic signal displays

    SciTech Connect

    1995-12-01

    This project investigated the feasibility of using light emitting diodes (LEDs) for red traffic signals in a demonstration program at 27 signalized intersections in the City of Philadelphia. LED traffic signals have the potential to achieve significant savings over standard incandescent signals in terms of energy usage and costs, signal relamping costs, signal system maintenance costs, tort liability, and environmental impact. Based on successful experience with the demonstration program, the City of Philadelphia is currently developing funding for the conversion of all existing red incandescent traffic signals at approximately 2,700 intersections to LED signals. This program is expected to cost approximately $4.0 million and save about $850,000 annually in energy costs. During late 1993 and early 1994, 212 red LED traffic signals (134 8-inch signals and 78 12-inch signals) were installed at 27 intersections in Philadelphia. The first group of 93 signals were installed at 13 prototypical intersections throughout the City. The remaining group of signals were installed on a contiguous route in West Philadelphia consisting of standard incandescent signals and LED signals interspersed in a random pattern.

  13. Final-Approach Spacing Aids (FASA) evaluation for terminal-area, time-based air traffic control

    NASA Technical Reports Server (NTRS)

    Credeur, Leonard; Capron, William R.; Lohr, Gary W.; Crawford, Daniel J.; Tang, Dershuen A.; Rodgers, William G., Jr.

    1993-01-01

    A jointly funded (NASA/FAA) real-time simulation study was conducted at NASA Langley Research Center to gather comparative performance data among three candidate final-approach spacing aid (FASA) display formats. Several objective measures of controller performance and their display eye-scan behavior as well as subjective workload and rating questionnaires were used. For each of two representative pattern-speed procedures (a 170-knot procedure and a 210-knot procedure with speed control aiding), data were gathered, via twelve FAA controllers, using four final-controller display format conditions (manual/ARTS 3, graphic marker, DICE countdown, and centerline slot marker). Measured runway separations were more precise with both the graphic marker and DICE countdown formats than with the centerline slot marker and both (graphic and DICE) improved precision relative to the manual/ARTS 3 format. For three separate rating criteria, the subject controllers ranked the FASA formats in the same order: graphic marker, DICE countdown, and centerline slot marker. The increased precision measured with the 210-knot pattern-speed procedure may indicate the potential for the application of speed-control aiding where higher pattern speeds are practical after the base-to-final turn. Also presented are key FASA issues, a rationale for the formats selected for testing, and their description.

  14. 49 CFR 236.403 - Signals at controlled point.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.403 Signals at controlled point. Signals at controlled point shall be...

  15. 49 CFR 236.403 - Signals at controlled point.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.403 Signals at controlled point. Signals at controlled point shall be...

  16. An expert system for air traffic control system

    NASA Technical Reports Server (NTRS)

    Sensui, Takashi

    1987-01-01

    The objective was to design a control logic which automates all or part of the guidance function for air traffic control systems. Particular interest was focused on automation of the terminal area control system. A preliminary study was done on the development of an expert system. The system may be used to assist controllers by providing them with feasible options in guiding each aircraft in the control area to its desired destination.

  17. Delivery performance of conventional aircraft by terminal-area, time-based air traffic control: A real-time simulation evaluation

    NASA Technical Reports Server (NTRS)

    Credeur, Leonard; Houck, Jacob A.; Capron, William R.; Lohr, Gary W.

    1990-01-01

    A description and results are presented of a study to measure the performance and reaction of airline flight crews, in a full workload DC-9 cockpit, flying in a real-time simulation of an air traffic control (ATC) concept called Traffic Intelligence for the Management of Efficient Runway-scheduling (TIMER). Experimental objectives were to verify earlier fast-time TIMER time-delivery precision results and obtain data for the validation or refinement of existing computer models of pilot/airborne performance. Experimental data indicated a runway threshold, interarrival-time-error standard deviation in the range of 10.4 to 14.1 seconds. Other real-time system performance parameters measured include approach speeds, response time to controller turn instructions, bank angles employed, and ATC controller message delivery-time errors.

  18. Road Traffic Control Based on Genetic Algorithm for Reducing Traffic Congestion

    NASA Astrophysics Data System (ADS)

    Shigehiro, Yuji; Miyakawa, Takuya; Masuda, Tatsuya

    In this paper, we propose a road traffic control method for reducing traffic congestion with genetic algorithm. In the not too distant future, the system which controls the routes of all vehicles in a certain area must be realized. The system should optimize the routes of all vehicles, however the solution space of this problem is enormous. Therefore we apply the genetic algorithm to this problem, by encoding the route of all vehicles to a fixed length chromosome. To improve the search performance, a new genetic operator called “path shortening” is also designed. The effectiveness of the proposed method is shown by the experiment.

  19. A new mechanism for metastability of under-saturated traffic responsible for time-delayed traffic breakdown at the signal

    NASA Astrophysics Data System (ADS)

    Jiang, Rui; Hu, Mao-Bin; Jia, Bin; Gao, Zi-You

    2014-05-01

    In this paper we introduce a new mechanism of metastability of under-saturated traffic at the signal that is responsible for a time-delayed traffic breakdown revealed by Kerner (2011). In our model, we assume that the metastability of under-saturated traffic at the signal is caused by a dependence of the mean time of driver acceleration from a queue at the signal on the driver's stopped time within the queue. With the use of Nagel-Schreckenberg model, we demonstrate that this mechanism of the metastability of city traffic can lead to the time-delayed traffic breakdown at the signal.

  20. Human factors aspects of air traffic control

    NASA Technical Reports Server (NTRS)

    Older, H. J.; Cameron, B. J.

    1972-01-01

    An overview of human factors problems associated with the operation of present and future air traffic control systems is presented. A description is included of those activities and tasks performed by air traffic controllers at each operational position within the present system. Judgemental data obtained from controllers concerning psychological dimensions related to these tasks and activities are also presented. The analysis includes consideration of psychophysiological dimensions of human performance. The role of the human controller in present air traffic control systems and his predicted role in future systems is described, particularly as that role changes as the result of the system's evolution towards a more automated configuration. Special attention is directed towards problems of staffing, training, and system operation. A series of ten specific research and development projects are recommended and suggested work plans for their implementation are included.

  1. Safety effects of traffic signing for left turn flashing yellow arrow signals.

    PubMed

    Schattler, Kerrie L; Gulla, Cody J; Wallenfang, Travis J; Burdett, Beau A; Lund, Jessica A

    2015-02-01

    In 2010, the left turn flashing yellow arrow (FYA) signal displays were installed at signalized intersections on state routes in the Peoria, Illinois, area. Supplemental traffic signs with text "Left Turn Yield on Flashing Yellow Arrow" were mounted on the mast arm adjacent to the left turn signal at over half of the FYA installations. The purpose of this paper is to present the results of the effectiveness evaluation of the FYA supplemental sign on safety. Analyses are presented on the effects of the FYA supplemental sign for all drivers and a subset of drivers age 65 and older. A crash-based comparison of 164 FYA approaches including 90 approaches with the sign and 74 approaches without the sign showed greater crash reductions when the supplemental FYA sign was present. The results also showed that crashes involving drivers age 65 and older did not experience the same magnitudes of crash reductions as compared to all drivers. The findings of this research indicate that supplemental FYA signs may help in improving safety for left-turning vehicles during the permissive interval. Thus, it is recommended that supplemental signs be used when initially implementing the FYA, and that effort to educate the driving public on new traffic control be made to further improve safety at signalized intersections. Copyright © 2014. Published by Elsevier Ltd.

  2. 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

  3. Multiple curved descending approaches and the air traffic control problem

    NASA Technical Reports Server (NTRS)

    Hart, S. G.; Mcpherson, D.; Kreifeldt, J.; Wemple, T. E.

    1977-01-01

    A terminal area air traffic control simulation was designed to study ways of accommodating increased air traffic density. The concepts that were investigated assumed the availability of the microwave landing system and data link and included: (1) multiple curved descending final approaches; (2) parallel runways certified for independent and simultaneous operation under IFR conditions; (3) closer spacing between successive aircraft; and (4) a distributed management system between the air and ground. Three groups each consisting of three pilots and two air traffic controllers flew a combined total of 350 approaches. Piloted simulators were supplied with computer generated traffic situation displays and flight instruments. The controllers were supplied with a terminal area map and digital status information. Pilots and controllers also reported that the distributed management procedure was somewhat more safe and orderly than the centralized management procedure. Flying precision increased as the amount of turn required to intersect the outer mark decreased. Pilots reported that they preferred the alternative of multiple curved descending approaches with wider spacing between aircraft to closer spacing on single, straight in finals while controllers preferred the latter option. Both pilots and controllers felt that parallel runways are an acceptable way to accommodate increased traffic density safely and expeditiously.

  4. 78 FR 36132 - National Standards for Traffic Control Devices; Manual on Uniform Traffic Control Devices for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ...; Manual on Uniform Traffic Control Devices for Streets and Highways AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notification; response to comments. SUMMARY: The Manual on Uniform Traffic Control... all components that are under consideration as the FHWA develops ideas for the next edition of...

  5. Evaluation of Intersection Traffic Control Measures through Simulation

    NASA Astrophysics Data System (ADS)

    Asaithambi, Gowri; Sivanandan, R.

    2015-12-01

    Modeling traffic flow is stochastic in nature due to randomness in variables such as vehicle arrivals and speeds. Due to this and due to complex vehicular interactions and their manoeuvres, it is extremely difficult to model the traffic flow through analytical methods. To study this type of complex traffic system and vehicle interactions, simulation is considered as an effective tool. Application of homogeneous traffic models to heterogeneous traffic may not be able to capture the complex manoeuvres and interactions in such flows. Hence, a microscopic simulation model for heterogeneous traffic is developed using object oriented concepts. This simulation model acts as a tool for evaluating various control measures at signalized intersections. The present study focuses on the evaluation of Right Turn Lane (RTL) and Channelised Left Turn Lane (CLTL). A sensitivity analysis was performed to evaluate RTL and CLTL by varying the approach volumes, turn proportions and turn lane lengths. RTL is found to be advantageous only up to certain approach volumes and right-turn proportions, beyond which it is counter-productive. CLTL is found to be advantageous for lower approach volumes for all turn proportions, signifying the benefits of CLTL. It is counter-productive for higher approach volume and lower turn proportions. This study pinpoints the break-even points for various scenarios. The developed simulation model can be used as an appropriate intersection lane control tool for enhancing the efficiency of flow at intersections. This model can also be employed for scenario analysis and can be valuable to field traffic engineers in implementing vehicle-type based and lane-based traffic control measures.

  6. 36 CFR 1004.12 - Traffic control devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  7. 36 CFR 4.12 - Traffic control devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  8. 36 CFR 4.12 - Traffic control devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  9. 36 CFR 1004.12 - Traffic control devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  10. 36 CFR 4.12 - Traffic control devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  11. 36 CFR 1004.12 - Traffic control devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  12. 36 CFR 1004.12 - Traffic control devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  13. 36 CFR 4.12 - Traffic control devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  14. 36 CFR 4.12 - Traffic control devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Traffic control devices. 4.12... VEHICLES AND TRAFFIC SAFETY § 4.12 Traffic control devices. Failure to comply with the directions of a traffic control device is prohibited unless otherwise directed by the superintendent....

  15. 36 CFR 1004.12 - Traffic control devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Traffic control devices. 1004.12 Section 1004.12 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.12 Traffic control devices. Failure to comply with the directions of a traffic control device...

  16. Measurement of electromagnetic fields generated by air traffic control radar systems with spectrum analysers.

    PubMed

    Barellini, A; Bogi, L; Licitra, G; Silvi, A M; Zari, A

    2009-12-01

    Air traffic control (ATC) primary radars are 'classical' radars that use echoes of radiofrequency (RF) pulses from aircraft to determine their position. High-power RF pulses radiated from radar antennas may produce high electromagnetic field levels in the surrounding area. Measurement of electromagnetic fields produced by RF-pulsed radar by means of a swept-tuned spectrum analyser are investigated here. Measurements have been carried out both in the laboratory and in situ on signals generated by an ATC primary radar.

  17. Space based radar application to air traffic control

    NASA Technical Reports Server (NTRS)

    Caime, W. J.

    1985-01-01

    Future control of increasing air traffic on international routes will require significant advances in techniques employed. Development is underway, but at this time does not include addition of radar coverage of vast areas of oceanic traffic. This paper addresses the potential for a space-based radar to provide detection and track of aircraft in future traffic scenarios. Factors that must be considered in further tradeoff and concept optimization are discussed. These include: (1) satellite constellation characteristics and associated coverage, (2) efficient use of available energy in track-while-scan strategies, (3) development of tracker approaches to accommodate inherent system constraints, and (4) the application of transponders to assist in dense traffic environments. The analysis assumes the continued development and availability of technology required for high spacecraft power systems (hundreds of kilowatts), and for radar subclutter visibility.

  18. Impact of a nitrogen emission control area (NECA) for ship traffic on the future air quality in the Baltic Sea region

    NASA Astrophysics Data System (ADS)

    Karl, Matthias; Geyer, Beate; Bieser, Johannes; Matthias, Volker; Quante, Markus; Jalkanen, Jukka-Pekka; Johansson, Lasse; Fridell, Erik

    2017-04-01

    Deposition of nitrogen compounds originating from shipping activities contribute to eutrophication of the Baltic Sea and coastal areas in the Baltic Sea region. Emissions of nitrogen oxides (NOx) from shipping on the Baltic Sea are comparable to the combined land-based emissions of NOx from Finland and Sweden and have been relatively stable over the last decade. However, expected future growth of maritime transport will result in higher fuel consumption and, if not compensated by increased transport efficiency or other measures, lead to higher total emissions of NOx from shipping. For the Baltic Sea a nitrogen emission control area (NECA) will become effective in 2021 - permitting only new built ships that are compliant with stringent Tier III emission limits - with the target of reducing NOx-emissions. In order to study the effect of implementing a Baltic Sea NECA-2021 on air quality and nitrogen deposition two future scenarios were designed; one with implementation of a NECA for the Baltic Sea starting in 2021 and another with no NECA implemented. The same increase of ship traffic was assumed for both future scenarios. Since complete fleet renewal with low NOx-emitting engines is not expected until 20-30 years after the NECA entry date, year 2040 was chosen as future scenario year. The Community Multiscale Air Quality (CMAQ) model was used to simulate the current and future air quality situation. The nested simulation runs with CMAQ were performed on a horizontal resolution of 4 km × 4 km for the entire Baltic Sea region. The meteorological year 2012 was chosen for the simulation of the current and future air quality situation since the 2m-temperature and precipitation anomalies of 2012 are closely aligned to the 2004-2014 decadal average over Baltic Proper. High-resolution meteorology obtained from COSMO-CLM was used for the regional simulations. Ship emissions were generated with the Ship Traffic Emission Assessment Model (STEAM) by the Finnish Meteorological

  19. Breakdowns in Coordination Between Air Traffic Controllers

    NASA Technical Reports Server (NTRS)

    Bearman, Chris; Orasanu, Judith; Miller, Ronald C.

    2011-01-01

    This talk outlines the complexity of coordination in air traffic control, introduces the NextGen technologies, identifies common causes for coordination breakdowns in air traffic control and examines whether these causes are likely to be reduced with the introduction of NextGen technologies. While some of the common causes of breakdowns will be reduced in a NextGen environment this conclusion should be drawn carefully given the current stage of development of the technologies and the observation that new technologies often shift problems rather than reduce them.

  20. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  1. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  2. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  3. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  4. 47 CFR 80.325 - Control of distress traffic.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Control of distress traffic. 80.325 Section 80... Safety Procedures § 80.325 Control of distress traffic. (a) Distress traffic consists of all messages relating to the immediate assistance required by the mobile station in distress. In distress traffic,...

  5. An original traffic additional emission model and numerical simulation on a signalized road

    NASA Astrophysics Data System (ADS)

    Zhu, Wen-Xing; Zhang, Jing-Yu

    2017-02-01

    Based on VSP (Vehicle Specific Power) model traffic real emissions were theoretically classified into two parts: basic emission and additional emission. An original additional emission model was presented to calculate the vehicle's emission due to the signal control effects. Car-following model was developed and used to describe the traffic behavior including cruising, accelerating, decelerating and idling at a signalized intersection. Simulations were conducted under two situations: single intersection and two adjacent intersections with their respective control policy. Results are in good agreement with the theoretical analysis. It is also proved that additional emission model may be used to design the signal control policy in our modern traffic system to solve the serious environmental problems.

  6. Effect of signals on two-route traffic system with real-time information

    NASA Astrophysics Data System (ADS)

    Tobita, Kazuhiro; Nagatani, Takashi

    2012-12-01

    We study the effect of signals on the vehicular traffic in the two-route system at the tour-time feedback strategy where the vehicles move ahead through a series of signals. The Nagel-Schreckenberg model is applied to the vehicular motion. The traffic signals are controlled by both cycle time and split. The tour times on two routes fluctuate periodically and alternately. The period increases with decreasing the split. Also, the tour time on each route varies with time by synchronizing with the density. The dependences of tour times and densities on both split and cycle time are clarified.

  7. Analysis of Controller Communication in En Route Air Traffic Control.

    ERIC Educational Resources Information Center

    Seamster, Thomas L.; And Others

    To contribute to an understanding of the elements of good air traffic controller communication with the objective of providing recommendations to improve controller communication training, two studies analyzed team communication, ground-air communication, and ground-line communication. The simulated and live traffic analyses examined established…

  8. A Course in English for Air Traffic Controllers.

    ERIC Educational Resources Information Center

    McCann, Paul; Thompson, Lesley

    A description is provided of a course, developed by the British Council in Madrid, Spain, to improve the English language training for trainee air traffic services personnel as a result of an increased demand for trained controllers over the next few years. The course aims to teach students in the areas of standard radiotelephony, non-routine…

  9. Simulation of traffic flow and control using conventional, fuzzy, and adaptive methods

    SciTech Connect

    Bisset, K.R.; Kelsey, R.L.

    1992-01-01

    This paper describes the graphical simulation of a traffic environment. The environment includes streets leading to an intersection, the intersection, vehicle traffic, and signal lights in the intersection controlled by different methods. The simulation allows for the study of parameters affecting traffic environments and the study of different control strategies for traffic signal lights, including conventional, fuzzy, and adaptive control methods. Realistic traffic environments are simulated including a cross intersection, with one or more lanes of traffic in each direction, with and without turn lanes. Vehicle traffic patterns are a mixture of cars going straight and making right or left turns. The free velocities of vehicles follow a normal distribution with a mean of the posted'' speed limit. Actual velocities depend on such factors as the proximity and velocity of surrounding traffic, approaches to intersections, and human response time. The simulation proves the be a useful tool for evaluating controller methods. Preliminary results show that larger quantities of traffic are handled'' by fuzzy control methods then by conventional control methods. Also, the average time spent waiting in traffic decreases with the use of fuzzy control versus conventional control.

  10. Simulation of traffic flow and control using conventional, fuzzy, and adaptive methods

    SciTech Connect

    Bisset, K.R.; Kelsey, R.L.

    1992-06-01

    This paper describes the graphical simulation of a traffic environment. The environment includes streets leading to an intersection, the intersection, vehicle traffic, and signal lights in the intersection controlled by different methods. The simulation allows for the study of parameters affecting traffic environments and the study of different control strategies for traffic signal lights, including conventional, fuzzy, and adaptive control methods. Realistic traffic environments are simulated including a cross intersection, with one or more lanes of traffic in each direction, with and without turn lanes. Vehicle traffic patterns are a mixture of cars going straight and making right or left turns. The free velocities of vehicles follow a normal distribution with a mean of the ``posted`` speed limit. Actual velocities depend on such factors as the proximity and velocity of surrounding traffic, approaches to intersections, and human response time. The simulation proves the be a useful tool for evaluating controller methods. Preliminary results show that larger quantities of traffic are ``handled`` by fuzzy control methods then by conventional control methods. Also, the average time spent waiting in traffic decreases with the use of fuzzy control versus conventional control.

  11. Human performance interfaces in air traffic control.

    PubMed

    Chang, Yu-Hern; Yeh, Chung-Hsing

    2010-01-01

    This paper examines how human performance factors in air traffic control (ATC) affect each other through their mutual interactions. The paper extends the conceptual SHEL model of ergonomics to describe the ATC system as human performance interfaces in which the air traffic controllers interact with other human performance factors including other controllers, software, hardware, environment, and organisation. New research hypotheses about the relationships between human performance interfaces of the system are developed and tested on data collected from air traffic controllers, using structural equation modelling. The research result suggests that organisation influences play a more significant role than individual differences or peer influences on how the controllers interact with the software, hardware, and environment of the ATC system. There are mutual influences between the controller-software, controller-hardware, controller-environment, and controller-organisation interfaces of the ATC system, with the exception of the controller-controller interface. Research findings of this study provide practical insights in managing human performance interfaces of the ATC system in the face of internal or external change, particularly in understanding its possible consequences in relation to the interactions between human performance factors.

  12. Air Traffic Control: Economics of Flight

    NASA Technical Reports Server (NTRS)

    Murphy, James R.

    2004-01-01

    Contents include the following: 1. Commercial flight is a partnership. Airlines. Pilots. Air traffic control. 2. Airline schedules and weather problems can cause delays at the airport. Delays are inevitable in de-regulated industry due to simple economics. 3.Delays can be mitigated. Build more runways/technology. Increase airspace supply. 4. Cost/benefit analysis determine justification.

  13. 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.

  14. Research on traffic flow characteristics at signal intersection

    NASA Astrophysics Data System (ADS)

    Zeng, Jun-Wei; Yu, Sen-Bin; Qian, Yong-Sheng; Wei, Xu-Ting; Feng, Xiao; Wang, Hui

    2017-09-01

    Based on the cautious driving behavior and the principle of the vehicles at left-side having priority to pass in the intersection, a two-dimensional cellular automata model for planar signalized intersection (NS-STCA) is established. The different turning vehicles are regarded as the research objects and the effect of the left-turn probability, signal cycle, vehicle flow density on traffic flow at the intersection is investigated.

  15. Predictability of Road Traffic and Congestion in Urban Areas

    PubMed Central

    Wang, Jingyuan; Mao, Yu; Li, Jing; Xiong, Zhang; Wang, Wen-Xu

    2015-01-01

    Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion. PMID:25849534

  16. Predictability of road traffic and congestion in urban areas.

    PubMed

    Wang, Jingyuan; Mao, Yu; Li, Jing; Xiong, Zhang; Wang, Wen-Xu

    2015-01-01

    Mitigating traffic congestion on urban roads, with paramount importance in urban development and reduction of energy consumption and air pollution, depends on our ability to foresee road usage and traffic conditions pertaining to the collective behavior of drivers, raising a significant question: to what degree is road traffic predictable in urban areas? Here we rely on the precise records of daily vehicle mobility based on GPS positioning device installed in taxis to uncover the potential daily predictability of urban traffic patterns. Using the mapping from the degree of congestion on roads into a time series of symbols and measuring its entropy, we find a relatively high daily predictability of traffic conditions despite the absence of any priori knowledge of drivers' origins and destinations and quite different travel patterns between weekdays and weekends. Moreover, we find a counterintuitive dependence of the predictability on travel speed: the road segment associated with intermediate average travel speed is most difficult to be predicted. We also explore the possibility of recovering the traffic condition of an inaccessible segment from its adjacent segments with respect to limited observability. The highly predictable traffic patterns in spite of the heterogeneity of drivers' behaviors and the variability of their origins and destinations enables development of accurate predictive models for eventually devising practical strategies to mitigate urban road congestion.

  17. 300 Area signal cable study

    SciTech Connect

    Whattam, J.W.

    1994-09-15

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system.

  18. Selection of Air Traffic Controllers,

    DTIC Science & Technology

    1984-08-01

    major part of this report consists of an integrated presentation of the significant research efforts that resulted in the adoption of the new selec...program, which is reported in the first 23 chapters ( Parts I through IV), is both a research document of major importance and a reference document for...state-of-the-art of controller performance assessment concludes Part III. Edited sunmariesof technical reports related to the development and validation

  19. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  20. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  1. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic controller...

  2. The Impact of a Signalized Crosswalk on Traffic Speed and Street-Crossing Behaviors of Residents in an Underserved Neighborhood.

    PubMed

    Schultz, Courtney L; Sayers, Stephen P; Wilhelm Stanis, Sonja A; Thombs, Lori A; Thomas, Ian M; Canfield, Shannon M

    2015-10-01

    Infrastructure improvements such as pedestrian crosswalks that calm traffic and increase access to physical activity opportunities could alleviate important barriers to active living in underserved communities with outdated built environments. The purpose of this study was to explore how the built environment influences street-crossing behaviors and traffic speeds in a low-income neighborhood with barriers to active living in Columbia, Missouri. In 2013, a signalized pedestrian crosswalk and 400-ft-long median was constructed along a busy 5-lane, high-speed arterial highway linking low-income housing with a park and downtown areas. Data collection occurred prior to June 2012, and after June 2013, completion of the project at the intervention site and control site. Direct observation of street-crossing behaviors was performed at designated intersections/crosswalks or non-designated crossing points. Traffic volume and speed were captured using embedded magnetic traffic detectors. At the intervention site, designated crossings increased at the new crosswalk (p < 0.001), but not at non-designated crossings (p = 0.52) or designated crossings at intersections (p = 0.41). At the control site, there was no change in designated crossings (p = 0.94) or non-designated crossings (p = 0.79). Motor vehicles traveling above the speed limit of 35 mph decreased from 62,056 (46 %) to 46,256 (35 %) (p < 0.001) at the intervention site and increased from 57,891 (49 %) to 65,725 (59 %) (p < 0.001) at the control site. The installation of a signalized crosswalk facilitated an increase in safe street crossings and calmed traffic volume and speed in an underserved neighborhood. We believe these findings have significant public health implications that could be critical to advocacy efforts to improve infrastructure projects in similar communities.

  3. Air Traffic Control Improvement Using Prioritized CSMA

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2001-01-01

    Version 7 simulations of the industry-standard network simulation software "OPNET" are presented of two applications of the Aeronautical Telecommunications Network (ATN), Controller Pilot Data Link Communications (CPDLC) and Automatic Dependent Surveillance-Broadcast mode (ADS-B), over VHF Data Link mode 2 (VDL-2). Communication is modeled for air traffic between just three cities. All aircraft are assumed to have the same equipage. The simulation involves Air Traffic Control (ATC) ground stations and 105 aircraft taking off, flying realistic free-flight trajectories, and landing in a 24-hr period. All communication is modeled as unreliable. Collision-less, prioritized carrier sense multiple access (CSMA) is successfully tested. The statistics presented include latency, queue length, and packet loss. This research may show that a communications system simpler than the currently accepted standard envisioned may not only suffice, but also surpass performance of the standard at a lower cost of deployment.

  4. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Highway traffic signal pre-emption. 234.261... Maintenance, Inspection, and Testing Inspections and Tests § 234.261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for which a railroad has maintenance...

  5. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Highway traffic signal pre-emption. 234.261 Section 234.261 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for...

  6. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Highway traffic signal pre-emption. 234.261... Maintenance, Inspection, and Testing Inspections and Tests § 234.261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for which a railroad has maintenance...

  7. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Highway traffic signal pre-emption. 234.261 Section 234.261 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for...

  8. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Highway traffic signal pre-emption. 234.261 Section 234.261 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD....261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for...

  9. Validation of Air Traffic Controller Workload Models

    DTIC Science & Technology

    1979-09-01

    SAR) tapes dtirinq the data reduc- tion phase of the project. Kentron International Limited provided the software support for the oroject. This included... ETABS ) or to revised traffic control procedures. The models also can be used to verify productivity benefits after new configurations have been...col- lected and processed manually. A preliminary compari- son has been made between standard NAS Stage A and ETABS operations at Miami. 1.2

  10. Computationally Lightweight Air-Traffic-Control Simulation

    NASA Technical Reports Server (NTRS)

    Knight, Russell

    2005-01-01

    An algorithm for computationally lightweight simulation of automated air traffic control (ATC) at a busy airport has been derived. The algorithm is expected to serve as the basis for development of software that would be incorporated into flight-simulator software, the ATC component of which is not yet capable of handling realistic airport loads. Software based on this algorithm could also be incorporated into other computer programs that simulate a variety of scenarios for purposes of training or amusement.

  11. 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.

  12. The acyltransferase LYCAT controls specific phosphoinositides and related membrane traffic

    PubMed Central

    Bone, Leslie N.; Dayam, Roya M.; Lee, Minhyoung; Kono, Nozomu; Fairn, Gregory D.; Arai, Hiroyuki; Botelho, Roberto J.; Antonescu, Costin N.

    2017-01-01

    Phosphoinositides (PIPs) are key regulators of membrane traffic and signaling. The interconversion of PIPs by lipid kinases and phosphatases regulates their functionality. Phosphatidylinositol (PI) and PIPs have a unique enrichment of 1-stearoyl-2-arachidonyl acyl species; however, the regulation and function of this specific acyl profile remains poorly understood. We examined the role of the PI acyltransferase LYCAT in control of PIPs and PIP-dependent membrane traffic. LYCAT silencing selectively perturbed the levels and localization of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] and phosphatidylinositol-3-phosphate and the membrane traffic dependent on these specific PIPs but was without effect on phosphatidylinositol-4-phosphate or biosynthetic membrane traffic. The acyl profile of PI(4,5)P2 was selectively altered in LYCAT-deficient cells, whereas LYCAT localized with phosphatidylinositol synthase. We propose that LYCAT remodels the acyl chains of PI, which is then channeled into PI(4,5)P2. Our observations suggest that the PIP acyl chain profile may exert broad control of cell physiology. PMID:28035047

  13. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic...

  14. 5 CFR 842.207 - Air traffic controllers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Air traffic controllers. 842.207 Section... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-BASIC ANNUITY Eligibility § 842.207 Air traffic controllers... misconduct, is entitled to an annuity— (1) After completing 25 years of service as an air traffic...

  15. Vehicular traffic flow at a non-signalized intersection

    NASA Astrophysics Data System (ADS)

    Ebrahim Foulaadvand, M.; Belbasi, Somayyeh

    2007-07-01

    We have developed a modified Nagel Schreckenberg cellular automata model for describing a conflicting vehicular traffic flow at the intersection of two streets. No traffic lights control the traffic flow. The approaching cars to the intersection yield to each other to avoid collision. Closed boundary condition is applied to the streets. Extensive Monte Carlo simulation is taken into account to find the model characteristics. In particular, we obtain the fundamental diagrams and show that the effect of the interaction of two streets can be regarded as a dynamic impurity located at the intersection point. Our results suggest that yielding mechanism gives rise to a high total flow throughout the intersection especially in the low density regime.

  16. Control techniques for an automated mixed traffic vehicle

    NASA Technical Reports Server (NTRS)

    Meisenholder, G. W.; Johnston, A. R.

    1977-01-01

    The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

  17. Control techniques for an automated mixed traffic vehicle

    NASA Technical Reports Server (NTRS)

    Meisenholder, G. W.; Johnston, A. R.

    1977-01-01

    The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

  18. Automated Conflict Resolution For Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2005-01-01

    The ability to detect and resolve conflicts automatically is considered to be an essential requirement for the next generation air traffic control system. While systems for automated conflict detection have been used operationally by controllers for more than 20 years, automated resolution systems have so far not reached the level of maturity required for operational deployment. Analytical models and algorithms for automated resolution have been traffic conditions to demonstrate that they can handle the complete spectrum of conflict situations encountered in actual operations. The resolution algorithm described in this paper was formulated to meet the performance requirements of the Automated Airspace Concept (AAC). The AAC, which was described in a recent paper [1], is a candidate for the next generation air traffic control system. The AAC's performance objectives are to increase safety and airspace capacity and to accommodate user preferences in flight operations to the greatest extent possible. In the AAC, resolution trajectories are generated by an automation system on the ground and sent to the aircraft autonomously via data link .The algorithm generating the trajectories must take into account the performance characteristics of the aircraft, the route structure of the airway system, and be capable of resolving all types of conflicts for properly equipped aircraft without requiring supervision and approval by a controller. Furthermore, the resolution trajectories should be compatible with the clearances, vectors and flight plan amendments that controllers customarily issue to pilots in resolving conflicts. The algorithm described herein, although formulated specifically to meet the needs of the AAC, provides a generic engine for resolving conflicts. Thus, it can be incorporated into any operational concept that requires a method for automated resolution, including concepts for autonomous air to air resolution.

  19. Stretchable Multichannel Electromyography Sensor Array Covering Large Area for Controlling Home Electronics with Distinguishable Signals from Multiple Muscles.

    PubMed

    Kim, Namyun; Lim, Taehoon; Song, Kwangsun; Yang, Sung; Lee, Jongho

    2016-08-17

    Physiological signals provide important information for biomedical applications and, more recently, in the form of wearable electronics for active interactions between bodies and external environments. Multiple physiological sensors are often required to map distinct signals from multiple points over large areas for more diverse applications. In this paper, we present a reusable, multichannel, surface electromyography (EMG) sensor array that covers multiple muscles over relatively large areas, with compliant designs that provide different levels of stiffness for repetitive uses, without backing layers. Mechanical and electrical characteristics along with distinct measurements from different muscles demonstrate the feasibility of the concept. The results should be useful to actively control devices in the environment with one array of wearable sensors, as demonstrated with home electronics.

  20. Automated mixed traffic transit vehicle microprocessor controller

    NASA Technical Reports Server (NTRS)

    Marks, R. A.; Cassell, P.; Johnston, A. R.

    1981-01-01

    An improved Automated Mixed Traffic Vehicle (AMTV) speed control system employing a microprocessor and transistor chopper motor current controller is described and its performance is presented in terms of velocity versus time curves. The on board computer hardware and software systems are described as is the software development system. All of the programming used in this controller was implemented using FORTRAN. This microprocessor controller made possible a number of safety features and improved the comfort associated with starting and shopping. In addition, most of the vehicle's performance characteristics can be altered by simple program parameter changes. A failure analysis of the microprocessor controller was generated and the results are included. Flow diagrams for the speed control algorithms and complete FORTRAN code listings are also included.

  1. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2011-10-01 2011-10-01 false Signals at adjacent control points....

  2. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points....

  3. 49 CFR 236.403 - Signals at controlled point.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Signals at controlled point. 236.403 Section 236..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.403 Signals at controlled point. Signals at controlled point shall be so...

  4. 49 CFR 236.403 - Signals at controlled point.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Signals at controlled point. 236.403 Section 236..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.403 Signals at controlled point. Signals at controlled point shall be so...

  5. Wide-area traffic: The failure of Poisson modeling

    SciTech Connect

    Paxson, V.; Floyd, S.

    1994-08-01

    Network arrivals are often modeled as Poisson processes for analytic simplicity, even though a number of traffic studies have shown that packet interarrivals are not exponentially distributed. The authors evaluate 21 wide-area traces, investigating a number of wide-area TCP arrival processes (session and connection arrivals, FTPDATA connection arrivals within FTP sessions, and TELNET packet arrivals) to determine the error introduced by modeling them using Poisson processes. The authors find that user-initiated TCP session arrivals, such as remote-login and file-transfer, are well-modeled as Poisson processes with fixed hourly rates, but that other connection arrivals deviate considerably from Poisson; that modeling TELNET packet interarrivals as exponential grievously underestimates the burstiness of TELNET traffic, but using the empirical Tcplib[DJCME92] interarrivals preserves burstiness over many time scales; and that FTPDATA connection arrivals within FTP sessions come bunched into ``connection bursts``, the largest of which are so large that they completely dominate FTPDATA traffic. Finally, they offer some preliminary results regarding how the findings relate to the possible self-similarity of wide-area traffic.

  6. 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

  7. Toward real-time en route air traffic control optimization

    NASA Astrophysics Data System (ADS)

    Jardin, Matthew Robert

    The increase in air traffic along the existing jet route structure has led to inefficiencies and frequent congestion in en route airspace. Analysis of air-traffic data suggests that direct operating costs might be reduced by about 4.5%, or $500 million per year, if aircraft were permitted to fly optimal wind routes instead of the structured routes allowed today. To enable aircraft to fly along unstructured optimal routes safely, automation is required to aid air-traffic controllers. This requires the global solution for conflict-free optimal routes for many aircraft in real time. The constraint that all aircraft must maintain adequate separation from one another results in a greater-than-exponential increase in the complexity of the multi-aircraft optimization problem. The main challenges addressed in this dissertation are in the areas of optimal wind routing, computationally efficient aircraft conflict detection, and efficient conflict resolution. A core contribution is the derivation of an analytical neighboring optimal control solution for the efficient computation of optimal wind routes. The neighboring optimal control algorithm uses an order of magnitude less computational effort to achieve the same performance as existing algorithms, and is easily extended to compute near-optimal conflict free trajectories. A conflict detection algorithm as been developed which eliminates the need to compute inter-aircraft distances. Simulation results are presented to demonstrate an integrated horizontal route-optimization and conflict-resolution method for air-traffic control. Conflict-free solutions have been computed for roughly double the current-day traffic density for a single flight level (over 600 aircraft) in less than 1 minute on a 450-MHz UNIX work station. This corresponds to a computation rate of better than 25 optimal routes per second. Extrapolation of the two-dimensional results to the multi-flight-level domain suggests that the complete solution for optimal

  8. 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

  9. 14 CFR 129.21 - Control of traffic.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  10. 14 CFR 129.21 - Control of traffic.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  11. 14 CFR 129.21 - Control of traffic.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  12. 14 CFR 129.21 - Control of traffic.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  13. 14 CFR 129.21 - Control of traffic.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Control of traffic. 129.21 Section 129.21... of traffic. (a) Subject to applicable immigration laws and regulations, each foreign air carrier must... communications with its aircraft and must assist station operators in directing traffic....

  14. A Fair Contention Access Scheme for Low-Priority Traffic in Wireless Body Area Networks

    PubMed Central

    Sajeel, Muhammad; Bashir, Faisal; Asfand-e-yar, Muhammad; Tauqir, Muhammad

    2017-01-01

    Recently, wireless body area networks (WBANs) have attracted significant consideration in ubiquitous healthcare. A number of medium access control (MAC) protocols, primarily derived from the superframe structure of the IEEE 802.15.4, have been proposed in literature. These MAC protocols aim to provide quality of service (QoS) by prioritizing different traffic types in WBANs. A contention access period (CAP)with high contention in priority-based MAC protocols can result in higher number of collisions and retransmissions. During CAP, traffic classes with higher priority are dominant over low-priority traffic; this has led to starvation of low-priority traffic, thus adversely affecting WBAN throughput, delay, and energy consumption. Hence, this paper proposes a traffic-adaptive priority-based superframe structure that is able to reduce contention in the CAP period, and provides a fair chance for low-priority traffic. Simulation results in ns-3 demonstrate that the proposed MAC protocol, called traffic- adaptive priority-based MAC (TAP-MAC), achieves low energy consumption, high throughput, and low latency compared to the IEEE 802.15.4 standard, and the most recent priority-based MAC protocol, called priority-based MAC protocol (PA-MAC). PMID:28832495

  15. A Fair Contention Access Scheme for Low-Priority Traffic in Wireless Body Area Networks.

    PubMed

    Henna, Shagufta; Sajeel, Muhammad; Bashir, Faisal; Asfand-E-Yar, Muhammad; Tauqir, Muhammad

    2017-08-23

    Recently, wireless body area networks (WBANs) have attracted significant consideration in ubiquitous healthcare. A number of medium access control (MAC) protocols, primarily derived from the superframe structure of the IEEE 802.15.4, have been proposed in literature. These MAC protocols aim to provide quality of service (QoS) by prioritizing different traffic types in WBANs. A contention access period (CAP)with high contention in priority-based MAC protocols can result in higher number of collisions and retransmissions. During CAP, traffic classes with higher priority are dominant over low-priority traffic; this has led to starvation of low-priority traffic, thus adversely affecting WBAN throughput, delay, and energy consumption. Hence, this paper proposes a traffic-adaptive priority-based superframe structure that is able to reduce contention in the CAP period, and provides a fair chance for low-priority traffic. Simulation results in ns-3 demonstrate that the proposed MAC protocol, called traffic- adaptive priority-based MAC (TAP-MAC), achieves low energy consumption, high throughput, and low latency compared to the IEEE 802.15.4 standard, and the most recent priority-based MAC protocol, called priority-based MAC protocol (PA-MAC).

  16. 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.

  17. 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

  18. 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.

  19. An efficient method to detect periodic behavior in botnet traffic by analyzing control plane traffic

    PubMed Central

    AsSadhan, Basil; Moura, José M.F.

    2013-01-01

    Botnets are large networks of bots (compromised machines) that are under the control of a small number of bot masters. They pose a significant threat to Internet’s communications and applications. A botnet relies on command and control (C2) communications channels traffic between its members for its attack execution. C2 traffic occurs prior to any attack; hence, the detection of botnet’s C2 traffic enables the detection of members of the botnet before any real harm happens. We analyze C2 traffic and find that it exhibits a periodic behavior. This is due to the pre-programmed behavior of bots that check for updates to download them every T seconds. We exploit this periodic behavior to detect C2 traffic. The detection involves evaluating the periodogram of the monitored traffic. Then applying Walker’s large sample test to the periodogram’s maximum ordinate in order to determine if it is due to a periodic component or not. If the periodogram of the monitored traffic contains a periodic component, then it is highly likely that it is due to a bot’s C2 traffic. The test looks only at aggregate control plane traffic behavior, which makes it more scalable than techniques that involve deep packet inspection (DPI) or tracking the communication flows of different hosts. We apply the test to two types of botnet, tinyP2P and IRC that are generated by SLINGbot. We verify the periodic behavior of their C2 traffic and compare it to the results we get on real traffic that is obtained from a secured enterprise network. We further study the characteristics of the test in the presence of injected HTTP background traffic and the effect of the duty cycle on the periodic behavior. PMID:25685512

  20. An efficient method to detect periodic behavior in botnet traffic by analyzing control plane traffic.

    PubMed

    AsSadhan, Basil; Moura, José M F

    2014-07-01

    Botnets are large networks of bots (compromised machines) that are under the control of a small number of bot masters. They pose a significant threat to Internet's communications and applications. A botnet relies on command and control (C2) communications channels traffic between its members for its attack execution. C2 traffic occurs prior to any attack; hence, the detection of botnet's C2 traffic enables the detection of members of the botnet before any real harm happens. We analyze C2 traffic and find that it exhibits a periodic behavior. This is due to the pre-programmed behavior of bots that check for updates to download them every T seconds. We exploit this periodic behavior to detect C2 traffic. The detection involves evaluating the periodogram of the monitored traffic. Then applying Walker's large sample test to the periodogram's maximum ordinate in order to determine if it is due to a periodic component or not. If the periodogram of the monitored traffic contains a periodic component, then it is highly likely that it is due to a bot's C2 traffic. The test looks only at aggregate control plane traffic behavior, which makes it more scalable than techniques that involve deep packet inspection (DPI) or tracking the communication flows of different hosts. We apply the test to two types of botnet, tinyP2P and IRC that are generated by SLINGbot. We verify the periodic behavior of their C2 traffic and compare it to the results we get on real traffic that is obtained from a secured enterprise network. We further study the characteristics of the test in the presence of injected HTTP background traffic and the effect of the duty cycle on the periodic behavior.

  1. Evaluation of Nanoporous Gold with Controlled Surface Structures for Laser Desorption Ionization (LDI) Analysis: Surface Area Versus LDI Signal Intensity

    NASA Astrophysics Data System (ADS)

    Jin, Jang Mi; Choi, Suhee; Kim, Young Hwan; Choi, Man Ho; Kim, Jongwon; Kim, Sunghwan

    2012-09-01

    The structural effect of a nanoporous gold (NPG) surface on the signal intensities of laser desorption ionization-mass spectrometry (LDI-MS) were investigated using NPG surfaces with controlled structures. The relationship between surface area and LDI efficiency was compared and evaluated. Comparisons between bare flat gold and NPG surfaces show that nanostructures increased LDI efficiency. We also found that the LDI signal decreased with increasing depth of nanoporous layers, thus increasing the surface area. This result agrees with a previous report (Shin J. A. et al., J. Am. Soc. Mass Spectrom. 2010, 21, 989) in which the LDI efficiency of small molecules decreased for ZnO wires with longer lengths. This observation was explained by the penetration and deposition of samples into locations inaccessible to photons because of structural screening. The LDI-MS analysis of oils with NPG surfaces (but without matrix) showed the same trend whereby the NPG with about a 200 nm depth of porous area showed the highest sensitivity. This study clearly shows that the active surface area for solution chemistry can differ from LDI-MS and that NPGs can function as a substrate for LDI oil analysis.

  2. A Teamwork-Oriented Air Traffic Control Simulator

    DTIC Science & Technology

    2006-06-01

    Traffic Control, Teamwork, Pilot , En-route controller, Approach Controller, Tower Controller, XML, OOP, RMI, Simulation. 16. PRICE CODE 17. SECURITY...Cases .........................................................30 4. Pilot Use Cases...Control Specification .............................................................43 4. Pilot Specification

  3. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

    PubMed Central

    Artuñedo, Antonio; del Toro, Raúl M.; Haber, Rodolfo E.

    2017-01-01

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks. PMID:28445398

  4. Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

    PubMed

    Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

    2017-04-26

    Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

  5. 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.

  6. Predicting Air Traffic Controller Workload: Trajectory Uncertainty as the Moderator of the Indirect Effect of Traffic Density on Controller Workload Through Traffic Conflict.

    PubMed

    Corver, Sifra Christina; Unger, Dana; Grote, Gudela

    2016-06-01

    Our study investigates whether trajectory uncertainty moderates the relationship between traffic conflict and workload. Furthermore, we examine if the indirect effect of traffic density on workload through traffic conflict is conditional on the presence of trajectory uncertainty. Although it is widely accepted that uncertainty related to the future trajectory of an aircraft impacts air traffic controller decision making, little is known about how the presence of trajectory uncertainty impacts controller workload. A better understanding of the impact on controller workload can improve workload prediction models for en route air traffic control. We collected data in a live operation environment, including workload ratings based on over-the-shoulder observations and real-time sector data. Hierarchical linear modeling was used to analyze the data. Trajectory uncertainty interacts with traffic conflict in such a way that the positive relationship between traffic conflict and workload is strongest in the presence of trajectory uncertainty. Furthermore, we found that the mediating effect of traffic density through traffic conflict is conditional on the presence of trajectory uncertainty. Our results indicate that workload prediction tools that do not incorporate trajectory uncertainty may underestimate workload under conditions of trajectory uncertainty, leading to possible overload situations of air traffic controllers. Sources that generate trajectory uncertainty, as well as their interaction effects with dynamic complexity metrics, should be acknowledged in workload prediction models to increase the predictive power of these models. Implications for future air traffic management operations as envisioned by SESAR and NextGen are discussed. © 2016, Human Factors and Ergonomics Society.

  7. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Information Feedback Strategies in a Signal Controlled Network with Overlapped Routes

    NASA Astrophysics Data System (ADS)

    Tian, Li-Jun; Huang, Hai-Jun; Liu, Tian-Liang

    2009-07-01

    We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers' route choice and the resultant system performance in a signal controlled network with overlapped routes. Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers' travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity.

  8. Automatic speed control of highway traffic

    NASA Technical Reports Server (NTRS)

    Klingman, E. E.

    1973-01-01

    Vehicle control system monitors all vehicles in its range, and automatically slows down speeding vehicles by activating governor in vehicle. System determines only maximum speed; speeds below maximum are controlled by vehicle operator. Loss of transmitted signal or activation of emergency over-ride will open fuel line and return control to operator.

  9. Amylin Receptor Signaling in the Ventral Tegmental Area is Physiologically Relevant for the Control of Food Intake

    PubMed Central

    Mietlicki-Baase, Elizabeth G; Rupprecht, Laura E; Olivos, Diana R; Zimmer, Derek J; Alter, Mark D; Pierce, R Christopher; Schmidt, Heath D; Hayes, Matthew R

    2013-01-01

    The ability of amylin, a pancreatic β-cell-derived neuropeptide, to promote negative energy balance has been ascribed to neural activation at the area postrema. However, despite amylin binding throughout the brain, the possible role of amylin signaling at other nuclei in the control of food intake has been largely neglected. We show that mRNA for all components of the amylin receptor complex is expressed in the ventral tegmental area (VTA), a mesolimbic structure mediating food intake and reward. Direct activation of VTA amylin receptors reduces the intake of chow and palatable sucrose solution in rats. This effect is mediated by reductions in meal size and is not due to nausea/malaise or prolonged suppression of locomotor activity. VTA amylin receptor activation also reduces sucrose self-administration on a progressive ratio schedule. Finally, antagonist studies provide novel evidence that VTA amylin receptor blockade increases food intake and attenuates the intake-suppressive effects of a peripherally administered amylin analog, suggesting that amylin receptor signaling in the VTA is physiologically relevant for food intake control and potentially clinically relevant for the treatment of obesity. PMID:23474592

  10. Amylin receptor signaling in the ventral tegmental area is physiologically relevant for the control of food intake.

    PubMed

    Mietlicki-Baase, Elizabeth G; Rupprecht, Laura E; Olivos, Diana R; Zimmer, Derek J; Alter, Mark D; Pierce, R Christopher; Schmidt, Heath D; Hayes, Matthew R

    2013-08-01

    The ability of amylin, a pancreatic β-cell-derived neuropeptide, to promote negative energy balance has been ascribed to neural activation at the area postrema. However, despite amylin binding throughout the brain, the possible role of amylin signaling at other nuclei in the control of food intake has been largely neglected. We show that mRNA for all components of the amylin receptor complex is expressed in the ventral tegmental area (VTA), a mesolimbic structure mediating food intake and reward. Direct activation of VTA amylin receptors reduces the intake of chow and palatable sucrose solution in rats. This effect is mediated by reductions in meal size and is not due to nausea/malaise or prolonged suppression of locomotor activity. VTA amylin receptor activation also reduces sucrose self-administration on a progressive ratio schedule. Finally, antagonist studies provide novel evidence that VTA amylin receptor blockade increases food intake and attenuates the intake-suppressive effects of a peripherally administered amylin analog, suggesting that amylin receptor signaling in the VTA is physiologically relevant for food intake control and potentially clinically relevant for the treatment of obesity.

  11. The Use of New Technology in the Control of Civil Air Traffic at Airway Junctions,

    DTIC Science & Technology

    1986-06-01

    8217) Report No. 86007 0c ROYAL SIGNALS AND RADAR ESTABLISHMENT, MALVERN 0 THE USE OF NEW TECHNOLOGY IN THE CONTROL OF CIVIL AIR TRAFFIC AT AIRWAY JUNCTIONS...Report 86007 Title: THE USE OF NEW TECHNOLOGY IN THE CONTROL OF CIVIL AIR TRAFFIC AT AIRWAY JUNCTIONS Author: P T Humphrey, AD4 Division. RSRE Date: .AV...44- 1986 SUMMARY This Report considers the methods which are used to deal with airway Junctions at present and reviews how new technology could

  12. Atlanta Air Route Traffic Control Center's involvement in aviation weather

    NASA Technical Reports Server (NTRS)

    Wood, W. D.

    1979-01-01

    The distribution of weather information throughout the Air Traffic Control System is discussed along with the development of meteorological radar, and the modifications to the Air Route Traffic Control Center radars for locating and determining the severity of storms' cells. The planned improvements in the availability of weather data to the control centers are listed.

  13. Distributed learning and multi-objectivity in traffic light control

    NASA Astrophysics Data System (ADS)

    Brys, Tim; Pham, Tong T.; Taylor, Matthew E.

    2014-01-01

    Traffic jams and suboptimal traffic flows are ubiquitous in modern societies, and they create enormous economic losses each year. Delays at traffic lights alone account for roughly 10% of all delays in US traffic. As most traffic light scheduling systems currently in use are static, set up by human experts rather than being adaptive, the interest in machine learning approaches to this problem has increased in recent years. Reinforcement learning (RL) approaches are often used in these studies, as they require little pre-existing knowledge about traffic flows. Distributed constraint optimisation approaches (DCOP) have also been shown to be successful, but are limited to cases where the traffic flows are known. The distributed coordination of exploration and exploitation (DCEE) framework was recently proposed to introduce learning in the DCOP framework. In this paper, we present a study of DCEE and RL techniques in a complex simulator, illustrating the particular advantages of each, comparing them against standard isolated traffic actuated signals. We analyse how learning and coordination behave under different traffic conditions, and discuss the multi-objective nature of the problem. Finally we evaluate several alternative reward signals in the best performing approach, some of these taking advantage of the correlation between the problem-inherent objectives to improve performance.

  14. Synaptic membrane rafts: traffic lights for local neurotrophin signaling?

    PubMed

    Zonta, Barbara; Minichiello, Liliana

    2013-10-18

    Lipid rafts, cholesterol and lipid rich microdomains, are believed to play important roles as platforms for the partitioning of transmembrane and synaptic proteins involved in synaptic signaling, plasticity, and maintenance. There is increasing evidence of a physical interaction between post-synaptic densities and post-synaptic lipid rafts. Localization of proteins within lipid rafts is highly regulated, and therefore lipid rafts may function as traffic lights modulating and fine-tuning neuronal signaling. The tyrosine kinase neurotrophin receptors (Trk) and the low-affinity p75 neurotrophin receptor (p75(NTR)) are enriched in neuronal lipid rafts together with the intermediates of downstream signaling pathways, suggesting a possible role of rafts in neurotrophin signaling. Moreover, neurotrophins and their receptors are involved in the regulation of cholesterol metabolism. Cholesterol is an important component of lipid rafts and its depletion leads to gradual loss of synapses, underscoring the importance of lipid rafts for proper neuronal function. Here, we review and discuss the idea that translocation of neurotrophin receptors in synaptic rafts may account for the selectivity of their transduced signals.

  15. Laser traffic control system upgrades for Maunakea

    NASA Astrophysics Data System (ADS)

    Stomski, Paul J.; Campbell, Randy; Cumming, Tom; Kackley, Russell; Kwok, Shui; Thomas, Jim

    2016-07-01

    The Maunakea Laser Traffic Control System (LTCS) has been in use since 2002 providing a mechanism to prevent the laser guide star or Rayleigh scatter from a laser propagated from one telescope from interfering with science observations at any of the other telescopes that share the mountain. LTCS has also been adopted at several other astronomical sites around the world to address that same need. In 2014 the stakeholders on Maunakea began the process of improving LTCS capability to support common observing techniques with enhanced First On Target (FoT) equity. The planned improvements include support for non-sidereal observing, laser checkout at zenith, dynamic field of view size, dithering, collision calculations even when a facility is not laser impacted, multiple alert severity levels, and software refactoring. The design of these improvements was completed in early 2015, and implementation is expected to be completed in 2016. This paper describes the Maunakea LTCS collaboration and the design of these planned improvements.

  16. ATLAS: A Traffic Load Aware Sensor MAC Design for Collaborative Body Area Sensor Networks

    PubMed Central

    Rahman, Md. Obaidur; Hong, Choong Seon; Lee, Sungwon; Bang, Young-Cheol

    2011-01-01

    In collaborative body sensor networks, namely wireless body area networks (WBANs), each of the physical sensor applications is used to collaboratively monitor the health status of the human body. The applications of WBANs comprise diverse and dynamic traffic loads such as very low-rate periodic monitoring (i.e., observation) data and high-rate traffic including event-triggered bursts. Therefore, in designing a medium access control (MAC) protocol for WBANs, energy conservation should be the primary concern during low-traffic periods, whereas a balance between satisfying high-throughput demand and efficient energy usage is necessary during high-traffic times. In this paper, we design a traffic load-aware innovative MAC solution for WBANs, called ATLAS. The design exploits the superframe structure of the IEEE 802.15.4 standard, and it adaptively uses the contention access period (CAP), contention free period (CFP) and inactive period (IP) of the superframe based on estimated traffic load, by applying a dynamic “wh” (whenever which is required) approach. Unlike earlier work, the proposed MAC design includes load estimation for network load-status awareness and a multi-hop communication pattern in order to prevent energy loss associated with long range transmission. Finally, ATLAS is evaluated through extensive simulations in ns-2 and the results demonstrate the effectiveness of the protocol. PMID:22247681

  17. ATLAS: a traffic load aware sensor MAC design for collaborative body area sensor networks.

    PubMed

    Rahman, Md Obaidur; Hong, Choong Seon; Lee, Sungwon; Bang, Young-Cheol

    2011-01-01

    In collaborative body sensor networks, namely wireless body area networks (WBANs), each of the physical sensor applications is used to collaboratively monitor the health status of the human body. The applications of WBANs comprise diverse and dynamic traffic loads such as very low-rate periodic monitoring (i.e., observation) data and high-rate traffic including event-triggered bursts. Therefore, in designing a medium access control (MAC) protocol for WBANs, energy conservation should be the primary concern during low-traffic periods, whereas a balance between satisfying high-throughput demand and efficient energy usage is necessary during high-traffic times. In this paper, we design a traffic load-aware innovative MAC solution for WBANs, called ATLAS. The design exploits the superframe structure of the IEEE 802.15.4 standard, and it adaptively uses the contention access period (CAP), contention free period (CFP) and inactive period (IP) of the superframe based on estimated traffic load, by applying a dynamic "wh" (whenever which is required) approach. Unlike earlier work, the proposed MAC design includes load estimation for network load-status awareness and a multi-hop communication pattern in order to prevent energy loss associated with long range transmission. Finally, ATLAS is evaluated through extensive simulations in ns-2 and the results demonstrate the effectiveness of the protocol.

  18. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... otherwise authorized by Air Traffic Control (ATC), no person may operate an aircraft in flight within the... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Operations in the Special Air Traffic Rule... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Special Flight Rules...

  19. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... otherwise authorized by Air Traffic Control (ATC), no person may operate an aircraft in flight within the... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Operations in the Special Air Traffic Rule... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Special Flight Rules...

  20. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... otherwise authorized by Air Traffic Control (ATC), no person may operate an aircraft in flight within the... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Operations in the Special Air Traffic Rule... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Special Flight Rules...

  1. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... otherwise authorized by Air Traffic Control (ATC), no person may operate an aircraft in flight within the... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Operations in the Special Air Traffic Rule... TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Special Flight Rules...

  2. New control strategy for the lattice hydrodynamic model of traffic flow

    NASA Astrophysics Data System (ADS)

    Zhu, Chenqiang; Zhong, Shiquan; Li, Guangyu; Ma, Shoufeng

    2017-02-01

    The new delayed-feedback control strategy is applied for lattice hydrodynamic model of traffic flow by considering the control signal of the variation rate of the optimal velocity. The linear stability condition is derived in the frequency-domain with control theory. Then, different feedback gains under the periodic boundary scenery and on-ramp scenery are simulated. The periodic boundary scenery provides an initial small disturbance situation on the circle road, while the on-ramp scenery reproduces the disturbance triggered by the on-ramp on the open road. Both the theoretical analysis and simulations show that this new control signal has a positive effect to suppress traffic jams.

  3. Preliminary Investigation of Workload on Intrastate Bus Traffic Controllers

    NASA Astrophysics Data System (ADS)

    Yen Bin, Teo; Azlis-Sani, Jalil; Nur Annuar Mohd Yunos, Muhammad; Ismail, S. M. Sabri S. M.; Tajedi, Noor Aqilah Ahmad

    2016-11-01

    The daily routine of bus traffic controller which involves high mental processes would have a direct impact on the level of workload. To date, the level of workload on the bus traffic controllers in Malaysia is relatively unknown. Excessive workload on bus traffic controllers would affect the control and efficiency of the system. This paper served to study the workload on bus traffic controllers and justify the needs to conduct further detailed research on this field. The objectives of this research are to identify the level of workload on the intrastate bus traffic controllers. Based on the results, recommendations will be proposed for improvements and future studies. The level of workload for the bus traffic controllers is quantified using questionnaire adapted from NASA TLX. Interview sessions were conducted for validation of workload. Sixteen respondents were involved and it was found that the average level of workload based on NASA TLX was 6.91. It was found that workload is not affected by gender and marital status. This study also showed that the level of workload and working experience of bus traffic controllers has a strong positive linear relationship. This study would serve as a guidance and reference related to this field. Since this study is a preliminary investigation, further detailed studies could be conducted to obtain a better comprehension regarding the bus traffic controllers.

  4. Efficient Conversation: The Talk between Pilots and Air Traffic Controllers.

    ERIC Educational Resources Information Center

    Simmons, James L.

    Two-way radio communications between air traffic controllers using radar on the ground to give airplane pilots instructions are of interest within the developing framework of the sociology of language. The main purpose of air traffic control language is efficient communication to promote flight safety. This study describes the standardized format…

  5. Air traffic coverage

    SciTech Connect

    George, L.L.

    1988-09-16

    The Federal Aviation Administration plans to consolidate several hundred air traffic control centers and TRACONs into area control facilities while maintaining air traffic coverage. This paper defines air traffic coverage, a performance measure of the air traffic control system. Air traffic coverage measures performance without controversy regarding delay and collision probabilities and costs. Coverage measures help evaluate alternative facility architectures and help schedule consolidation. Coverage measures also help evaluate protocols for handling one facility's air traffic to another facility in case of facility failure. Coverage measures help evaluate radar, communications and other air traffic control systems and procedures. 4 refs., 2 figs.,

  6. Quantifying the impact of adaptive traffic control systems on crash frequency and severity: Evidence from Oakland County, Michigan.

    PubMed

    Fink, Joshua; Kwigizile, Valerian; Oh, Jun-Seok

    2016-06-01

    Despite seeing widespread usage worldwide, adaptive traffic control systems have experienced relatively little use in the United States. Of the systems used, the Sydney Coordinated Adaptive Traffic System (SCATS) is the most popular in America. Safety benefits of these systems are not as well understood nor as commonly documented. This study investigates the safety benefits of adaptive traffic control systems by using the large SCATS-based system in Oakland County, MI known as FAST-TRAC. This study uses data from FAST-TRAC-controlled intersections in Oakland County and compares a wide variety of geometric, traffic, and crash characteristics to similar intersections in metropolitan areas elsewhere in Michigan. Data from 498 signalized intersections are used to conduct a cross-sectional analysis. Negative binomial models are used to estimate models for three dependent crash variables. Multinomial logit models are used to estimate an injury severity model. A variable tracking the presence of FAST-TRAC controllers at intersections is used in all models to determine if a SCATS-based system has an impact on crash occurrences or crash severity. Estimates show that the presence of SCATS-based controllers at intersections is likely to reduce angle crashes by up to 19.3%. Severity results show a statistically significant increase in non-serious injuries, but not a significant reduction in incapacitating injuries or fatal accidents. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

  7. 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.

  8. Traffic particles and occurrence of acute myocardial infarction: a case-control analysis.

    PubMed

    Tonne, C; Yanosky, J; Gryparis, A; Melly, S; Mittleman, M; Goldberg, R; von Klot, S; Schwartz, J

    2009-12-01

    We modelled exposure to traffic particles using a latent variable approach and investigated whether long-term exposure to traffic particles is associated with an increase in the occurrence of acute myocardial infarction (AMI) using data from a population-based coronary disease registry. Cases of individually validated AMI were identified between 1995 and 2003 as part of the Worcester Heart Attack Study. Population controls were selected from Massachusetts, USA, resident lists. NO(2) and PM(2.5) filter absorbance were measured at 36 locations throughout the study area. The air pollution data were used to estimate exposure to traffic particles using a semiparametric latent variable regression model. Conditional logistic models were used to estimate the association between exposure to traffic particles and occurrence of AMI. Modelled exposure to traffic particles was highest near the city of Worcester. Cases of AMI were more exposed to traffic and traffic particles compared to controls. An interquartile range increase in modelled traffic particles was associated with a 10% (95% CI 4% to 16%) increase in the odds of AMI. Accounting for spatial dependence at the census tract, but not block group, scale substantially attenuated this association. These results provide some support for an association between long-term exposure to traffic particles and risk of AMI. The results were sensitive to the scale selected for the analysis of spatial dependence, an issue that requires further investigation. The latent variable model captured variation in exposure, although on a relatively large spatial scale.

  9. Feedback control for car following model based on two-lane traffic flow

    NASA Astrophysics Data System (ADS)

    Ge, Hong-xia; Meng, Xiang-pei; Zhu, Hui-bing; Li, Zhi-Peng

    2014-08-01

    In the paper, two-lane traffic flow considering lane changing behaviors has been discussed based on the control theory, and the friction interference which is from the neighbor lane has been taken into account. By using the control method, the stability condition is derived. The feedback signals, which include vehicular information from both lanes, acting on the two-lane traffic system have been introduced into the Full Velocity Difference car-following model. In the end, simulations are conducted to examine the validity and reasonability of the control method. It is proven that lane changing behaviors can aggravate the traffic perturbation. The traffic flow congestion could be suppressed by using the control method and the simulation results are in good agreement with the theoretical analysis.

  10. Local-Area Based Traffic Splitter for Improving Performance Using Subnetting

    NASA Astrophysics Data System (ADS)

    Yadav, Meenakshi; Mittal, Mohit Kumar

    2010-11-01

    This document provides an overview of LAN traffic splitter. The tool "Local-Area based Traffic splitter" is based on subnetting techniques. It is basically used for calculating subnets for sub-dividing the LAN. Subnetting an IP Network can be done for a variety of reasons, including organization, use of different physical media (such as Ethernet, FDDI, WAN, etc.), preservation of address space, and security. The most common reason is to control network traffic. There are various techniques for calculating subnets that are considered by this tool. This paper will explore the various features of this tool and will also check the effect of subnetting after implementing it on the LAN. These instructions give you basic guidelines for preparing camera-ready papers for conference proceedings.

  11. An algorithm for terminal air traffic control

    NASA Technical Reports Server (NTRS)

    Sarris, A. H.; Athans, M.

    1971-01-01

    An area-navigation method for automatic control of aircraft arriving in a random fashion from the en-route centers to the near terminal area is proposed. Control is exercised by a ground computer that sequences and schedules the aircraft. Altitude segregation is used to separate aircraft in velocity classes. Merging of all aircraft occurs near the outer marker. The merging region is designed so that no near misses will occur if the aircraft follow the assigned trajectories.

  12. Near-to-eye display concepts for air traffic controllers

    NASA Astrophysics Data System (ADS)

    Ruffner, John W.; Fulbrook, Jim E.; Foglia, Marc

    2004-09-01

    Tower controllers are responsible for maintaining safe separation between airborne aircraft in the airport traffic control area, and separation between aircraft, equipment, and personnel on the airport surface. The objective of this project was to develop and demonstrate an out-the-window, augmented viewing system concept for Air Force air traffic control tower personnel to reduce look-down time within the tower and to optimize visual airfield operations, particularly during limited visibility conditions. We characterized controller tasks where a near-to-eye display greatly aids performance and identified form factor variables that influence user acceptability of hardware configurations. We developed an "out-the-window concept of operation" and analyzed the hardware requirements and feasibility of three near-to-eye viewing systems: two head-mounted monocular displays (HMMD) and a held-to-head binocular display (HHBD). When fully developed, these display prototypes should enhance tower controller situation awareness, and reduce such distractions as having to frequently attend to and respond to head-down (console) display information. There are potential users of this display concept in all branches of the military services, and in the commercial sector. There is also potential utility for surface surveillance operations in support of homeland security, law enforcement personnel, rescue workers, firefighters, and special operations forces in non-aviation applications.

  13. The influence of traffic signal solutions on self-reported road-crossing behavior.

    PubMed

    Di Stasi, Leandro L; Megías, Alberto; Cándido, Antonio; Maldonado, Antonio; Catena, Andrés

    2015-01-07

    Injury to pedestrians is a major safety hazard in many countries. Since the beginning of the last century, modern cities have been designed around the use of motor vehicles despite the unfavourable interactions between the vehicles and pedestrians. This push towards urbanization resulted in a substantial number of crashes and fatalities involving pedestrians every day, all over the world. Thus, improving the design of urban cities and townships is a pressing issue for modern society. The study presented here provides a characterization of pedestrian safety problems, with the emphasis on signalized crosswalks (i.e. traffic signal) design solutions. We tested the impact of seven different traffic light configurations (steady [green, yellow, and red], flashing [green, yellow, and red], and light off) on pedestrian self-reported road-crossing behavior, using a 11-point scale -ranging from 0 ("I never cross in this situation") to 10 ("I always cross in this situation"). Results showed that mandatory solutions (steady green vs. steady red) are the best solutions to avoid unsafe pedestrian behaviors while crossing controlled intersections (frequency of crossing: Mgreen = 9.4 ± 1 vs. Mred = 2.6 ± 2). These findings offer important guidelines for the design of future traffic signals for encouraging a pedestrian/transit-friendly environment.

  14. Detecting Approaching Vehicles at Streets with No Traffic Control

    ERIC Educational Resources Information Center

    Emerson, Robert Wall; Sauerburger, Dona

    2008-01-01

    This study assessed the ability of people with visual impairments to reliably detect oncoming traffic at crossing situations with no traffic control. In at least one condition, the participants could not hear vehicles to afford a safe crossing time when sound levels were as quiet as possible. Significant predictors of detection accounted for a…

  15. Detecting Approaching Vehicles at Streets with No Traffic Control

    ERIC Educational Resources Information Center

    Emerson, Robert Wall; Sauerburger, Dona

    2008-01-01

    This study assessed the ability of people with visual impairments to reliably detect oncoming traffic at crossing situations with no traffic control. In at least one condition, the participants could not hear vehicles to afford a safe crossing time when sound levels were as quiet as possible. Significant predictors of detection accounted for a…

  16. Hybrid and electric low-noise cars cause an increase in traffic accidents involving vulnerable road users in urban areas.

    PubMed

    Brand, Stephan; Petri, Maximilian; Haas, Philipp; Krettek, Christian; Haasper, Carl

    2013-01-01

    Due to resource scarcity, the number of low-noise and electric cars is expected to increase rapidly. The frequent use of these cars will lead to a significant reduction of traffic related noise and pollution. On the other hand, due to the adaption and conditioning of vulnerable road users the number of traffic accidents involving pedestrians and bicyclists is postulated to increase as well. Children, older people with reduced eyesight and the blind are especially reliant on a combination of acoustic and visual warning signals with approaching or accelerating vehicles. This is even more evident in urban areas where the engine sound is the dominating sound up to 30 kph (kilometres per hour). Above this, tyre-road interaction is the main cause of traffic noise. With the missing typical engine sound a new sound design is necessary to prevent traffic accidents in urban areas. Drivers should not be able to switch the sound generator off.

  17. Analysis and Modeling of Practical Experiment on IP Traffic Control

    NASA Astrophysics Data System (ADS)

    Suzuki, Tadamichi; Ito, Jungo; Nakano, Kazushi; Miki, Tetsuya

    In this paper, we focus on a practical experiment concerning IP traffic engineering over Multi-Protocol Label Switching (MPLS), especially which features feedback control capabilities. We present control-theoretic analysis of the experimental results based on acquired knowledge of actual network behavior. Because stable automated control capabilities are key issues in IP traffic engineering, we model an IP traffic control system based on the resulting analysis. In addition, comparison between simulated network behavior and actual one shows this model to have a high degree of stability, with a high potential for application to real networks.

  18. Aeronautical Satellite Data Link System (SDLS) for high-density air-traffic areas

    NASA Technical Reports Server (NTRS)

    Delrieu, Alain; Loisy, Claude; Clinch, Philip; Benhaim, Philippe

    1995-01-01

    The European Space Agency has recently commissioned a study to investigate the feasibility of a low-cost aeronautical Satellite Data Link System (SDLS) to provide for the needs of Air Traffic Services, i.e. safety related communications over continental areas with high air-traffic density. This study is placed in today's context which sees the first generation of Aeronautical Mobile Satellite System (AMSS) being gradually but restrictively put into service in oceanic airspaces with low air-traffic density. This paper first discusses the case of ATS dedicated versus mixed (ATS and commercial) Comms service provision and identifies the specific ATS comms requirements context. Specific emphasis is put on the ICAO (International Civil Aviation Organization) standardization framework for both the ATN (Aeronautical Telecommunication Network) and the SSR (Secondary Surveillance Radar) Mode S specific services. An architectural system and network design for a future SDLS is then proposed, such as to meet the ATS comms requirements within the realm of existing technologies. To minimize development risk and cost, consideration is given to re-use the ESA-developed Land Mobile Communication Technology, known as MSBN (Mobile Satellite Business Network) featuring distinct subnetworks. It is particularly suited to an ATM (Air Traffic Management) decentralized architecture made of independent ATC (Air Traffic Control) Centers. Finally the study follow-on phase is introduced, which is intended to cover system design and development leading to a demonstration program, as a first step towards proposals for international standardization and acceptance.

  19. Trajectory Specification for Automation of Terminal Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Paielli, Russell A.

    2016-01-01

    "Trajectory specification" is the explicit bounding and control of aircraft tra- jectories such that the position at each point in time is constrained to a precisely defined volume of space. The bounding space is defined by cross-track, along-track, and vertical tolerances relative to a reference trajectory that specifies position as a function of time. The tolerances are dynamic and will be based on the aircraft nav- igation capabilities and the current traffic situation. A standard language will be developed to represent these specifications and to communicate them by datalink. Assuming conformance, trajectory specification can guarantee safe separation for an arbitrary period of time even in the event of an air traffic control (ATC) sys- tem or datalink failure, hence it can help to achieve the high level of safety and reliability needed for ATC automation. As a more proactive form of ATC, it can also maximize airspace capacity and reduce the reliance on tactical backup systems during normal operation. It applies to both enroute airspace and the terminal area around airports, but this paper focuses on arrival spacing in the terminal area and presents ATC algorithms and software for achieving a specified delay of runway arrival time.

  20. A generic solution for unwanted traffic control through trust management

    NASA Astrophysics Data System (ADS)

    Yan, Zheng; Kantola, Raimo; Shen, Yue

    2014-01-01

    The Internet has dramatically changed our daily life. But it is also bogged down by unwanted traffic, which is malicious, harmful or unexpected for its receivers. In order to control the unwanted traffic over the Internet, especially the mobile Internet, in this paper, we propose a generic unwanted traffic control (UTC) solution through trust management. It can control unwanted traffic from its source to destinations in a personalized manner according to trust evaluation at a Global Trust Operator, traffic and behavior analysis at hosts and traffic observation in the Internet. Thus, it can conduct UTC by integrating distributed and centralized functions and supporting both defensive and offensive approaches. Simulation based evaluation shows that the solution is effective with regard to accuracy and efficiency for botnet intrusion and DDoS intrusion via reflectors. It is also robust against a number of malicious system attacks, such as hide evidence attack, bad mouthing attack, on-off attack, malicious attack by an Internet Service Provider and combinations of the above, playing in conjunction with traffic intrusions. Meanwhile, the solution can provide a personalized UTC based on unwanted traffic detection behaviors.

  1. Investigation of the impact of low cost traffic engineering measures on road safety in urban areas.

    PubMed

    Yannis, George; Kondyli, Alexandra; Georgopoulou, Xenia

    2014-01-01

    This paper investigates the impact of low cost traffic engineering measures (LCTEMs) on the improvement of road safety in urban areas. A number of such measures were considered, such as speed humps, woonerfs, raised intersections and other traffic calming measures, which have been implemented on one-way, one-lane roads in the Municipality of Neo Psychiko in the Greater Athens Area. Data were analysed using the before-and-after safety analysis methodology with large control group. The selected control group comprised of two Municipalities in the Athens Greater Area, which present similar road network and land use characteristics with the area considered. The application of the methodology showed that the total number of crashes presented a statistically significant reduction, which can be possibly attributed to the introduction of LCTEMs. This reduction concerns passenger cars and single-vehicle crashes and is possibly due to the behavioural improvement of drivers of 25 years old or more. The results of this research are very useful for the identification of the appropriate low cost traffic engineering countermeasures for road safety problems in urban areas.

  2. Automatic, time-interval traffic counts for recreation area management planning

    Treesearch

    D. L. Erickson; C. J. Liu; H. K. Cordell

    1980-01-01

    Automatic, time-interval recorders were used to count directional vehicular traffic on a multiple entry/exit road network in the Red River Gorge Geological Area, Daniel Boone National Forest. Hourly counts of entering and exiting traffic differed according to recorder location, but an aggregated distribution showed a delayed peak in exiting traffic thought to be...

  3. Cockpit displayed traffic information and distributed management in air traffic control

    NASA Technical Reports Server (NTRS)

    Kreifeldt, J. G.

    1980-01-01

    A graphical display of information (such as surrounding aircraft and navigation routes) in the cockpit on a cathode ray tube has been proposed for improving the safety, orderliness, and expeditiousness of the air traffic control system. An investigation of this method at NASA-Ames indicated a large reduction in controller verbal work load without increasing pilot verbal load; the visual work may be increased. The cockpit displayed traffic and navigation information system reduced response delays permitting pilots to maintain their spacing more closely and precisely than when depending entirely on controller-issued radar vectors and speed command.

  4. An optimal general type-2 fuzzy controller for Urban Traffic Network.

    PubMed

    Khooban, Mohammad Hassan; Vafamand, Navid; Liaghat, Alireza; Dragicevic, Tomislav

    2017-01-01

    Urban traffic network model is illustrated by state-charts and object-diagram. However, they have limitations to show the behavioral perspective of the Traffic Information flow. Consequently, a state space model is used to calculate the half-value waiting time of vehicles. In this study, a combination of the general type-2 fuzzy logic sets and the Modified Backtracking Search Algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters of input and output membership functions are optimized simultaneously by the novel heuristic algorithm MBSA. A comparison is made between the achieved results with those of optimal and conventional type-1 fuzzy logic controllers.

  5. Lightweight simulation of air traffic control using simple temporal networks

    NASA Technical Reports Server (NTRS)

    Knight, Russell

    2005-01-01

    We provide a formulation of the air traffic control problem and a solver for this problem that makes use of temporal constraint networks and simple geometric reasoning. We provide results showing that this approach is practical for realistic simulated problems.

  6. Lightweight simulation of air traffic control using simple temporal networks

    NASA Technical Reports Server (NTRS)

    Knight, Russell

    2005-01-01

    We provide a formulation of the air traffic control problem and a solver for this problem that makes use of temporal constraint networks and simple geometric reasoning. We provide results showing that this approach is practical for realistic simulated problems.

  7. 24. DETAIL ELEVATION OF SECOND FLOOR AIR TRAFFIC CONTROL CENTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. DETAIL ELEVATION OF SECOND FLOOR AIR TRAFFIC CONTROL CEN-TER DOOR. - Newark International Airport, Administration Building, Brewster Road between Route 21 & New Jersey Turnpike Exchange No. 14, Newark, Essex County, NJ

  8. 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.

  9. Innovative traffic control: Technology practice in Europe. International technology exchange program

    SciTech Connect

    Tignor, S.C.; Brown, L.L.; Butner, J.L.; Cunard, R.; Davis, S.C.

    1999-08-01

    This summary report describes a may 1998 transportation technology scanning tour of four European countries. The tour was co-sponsored by FHWA, AASHTO, and TRB. The tour team consisted of 10 traffic engineers who visited England, France, Germany, and Sweden to observe traffic control devices and methodology and to determine if any European practices should and could be recommended for use in the United States. This report is organized into five key chapters: Traffic Control Devices, Freeway Control, Operational Practices, Information Management, and Administrative Practices. Among the devices and practices recommended for further study for US adoption are specific freeway pavement markings, variable speed control, lane control signals, intelligent speed adaptation, innovative intersection control, and variable message signs that incorporate pictograms. The report includes statements for proposed research problems.

  10. Nextgen Technologies for Mid-Term and Far-Term Air Traffic Control Operations

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas

    2009-01-01

    This paper describes technologies for mid-term and far-term air traffic control operations in the Next Generation Air Transportation System (NextGen). The technologies were developed and evaluated with human-in-the-loop simulations in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center. The simulations were funded by several research focus areas within NASA's Airspace Systems program and some were co-funded by the FAA's Air Traffic Organization for Planning, Research and Technology.

  11. Congestion control for low-priority filler traffic

    NASA Astrophysics Data System (ADS)

    Ott, Brian A.; Warnky, Timothy; Liberatore, Vincenzo

    2003-08-01

    As the cost of Internet access rises and the amount of deployed bandwidth increases, a way to make efficient use of the oft-unused bandwidth is desired. Simply providing a lower priority for traffic than best effort allows this bandwidth to be used without noticeable interference with regular traffic. Because bursts of normal traffic are given priority over this background, or filler, traffic, a more aggressive congestion control protocol is called for in the filler traffic. In our paper, we compare numerous versions of TCP-like congestion control of our own design, over which to implement low-priority traffic, by using the unused bandwidth at any given time. These protocols are divided into six "classes," which differ by the core congestion control algorithm and use different constants. Using the ns-2 network simulator, we collected network traces using each of our protocols in different network configurations, with multiple parameters for each configuration. These configurations simulated high- and low-bandwidth and latency networks. We compared the resulting throughput and sharing - the cumulative variation of throughput over each stream, normalized by the total throughput over the link - to our chosen baseline, TCP Sack. Most of the basic algorithms performed as well as or better than Sack in a background traffic environment, especially in terms of throughput. Using features from multiple classes, we also designed a more complex protocol that performed better than Sack in almost every environment, and performed better than the other algorithms in general.

  12. 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.

  13. 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.

  14. 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.

  15. Task Analysis Assessment on Intrastate Bus Traffic Controllers

    NASA Astrophysics Data System (ADS)

    Yen Bin, Teo; Azlis-Sani, Jalil; Nur Annuar Mohd Yunos, Muhammad; Ismail, S. M. Sabri S. M.; Tajedi, Noor Aqilah Ahmad

    2016-11-01

    Public transportation acts as social mobility and caters the daily needs of the society for passengers to travel from one place to another. This is true for a country like Malaysia where international trade has been growing significantly over the past few decades. Task analysis assessment was conducted with the consideration of cognitive ergonomic view towards problem related to human factors. Conducting research regarding the task analysis on bus traffic controllers had allowed a better understanding regarding the nature of work and the overall monitoring activities of the bus services. This paper served to study the task analysis assessment on intrastate bus traffic controllers and the objectives of this study include to conduct task analysis assessment on the bus traffic controllers. Task analysis assessment for the bus traffic controllers was developed via Hierarchical Task Analysis (HTA). There are a total of five subsidiary tasks on level one and only two were able to be further broken down in level two. Development of HTA allowed a better understanding regarding the work and this could further ease the evaluation of the tasks conducted by the bus traffic controllers. Thus, human error could be reduced for the safety of all passengers and increase the overall efficiency of the system. Besides, it could assist in improving the operation of the bus traffic controllers by modelling or synthesizing the existing tasks if necessary.

  16. Solving a signalized traffic intersection problem with an hyperbolic penalty function

    NASA Astrophysics Data System (ADS)

    Melo, Teófilo; Monteiro, M. Teresa T.; Matias, João

    2012-09-01

    Mathematical Program with Complementarity Constraints (MPCC) finds many applications in fields such as engineering design, economic equilibrium and mathematical programming theory itself. A queueing system model resulting from a single signalized intersection regulated by pre-timed control in traffic network is considered. The model is formulated as an MPCC problem. A MATLAB implementation based on an hyperbolic penalty function is used to solve this practical problem, computing the total average waiting time of the vehicles in all queues and the green split allocation. The problem was codified in AMPL.

  17. 49 CFR 236.402 - Signals controlled by track circuits and control operator.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.402 Signals controlled by track circuits and... 49 Transportation 4 2011-10-01 2011-10-01 false Signals controlled by track circuits and...

  18. 49 CFR 236.402 - Signals controlled by track circuits and control operator.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.402 Signals controlled by track circuits and... 49 Transportation 4 2010-10-01 2010-10-01 false Signals controlled by track circuits and...

  19. Digital signal processing and control and estimation theory -- Points of tangency, area of intersection, and parallel directions

    NASA Technical Reports Server (NTRS)

    Willsky, A. S.

    1976-01-01

    A number of current research directions in the fields of digital signal processing and modern control and estimation theory were studied. Topics such as stability theory, linear prediction and parameter identification, system analysis and implementation, two-dimensional filtering, decentralized control and estimation, image processing, and nonlinear system theory were examined in order to uncover some of the basic similarities and differences in the goals, techniques, and philosophy of the two disciplines. An extensive bibliography is included.

  20. Automatic Data Traffic Control on DSM Architecture

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Jin, Hao-Qiang; Yan, Jerry; Kwak, Dochan (Technical Monitor)

    2000-01-01

    We study data traffic on distributed shared memory machines and conclude that data placement and grouping improve performance of scientific codes. We present several methods which user can employ to improve data traffic in his code. We report on implementation of a tool which detects the code fragments causing data congestions and advises user on improvements of data routing in these fragments. The capabilities of the tool include deduction of data alignment and affinity from the source code; detection of the code constructs having abnormally high cache or TLB misses; generation of data placement constructs. We demonstrate the capabilities of the tool on experiments with NAS parallel benchmarks and with a simple computational fluid dynamics application ARC3D.

  1. Ergonomic investigation on pedestrian crossing with traffic light signalization.

    PubMed

    Amado, Giuseppe; de Moraes, Anamaria

    2012-01-01

    This article is about the risk behavior adopted by pedestrians at crosswalks with traffic light equipment. It was observed that many pedestrians take risk to cross the Presidente Vargas Avenue. This avenue is located in downtown in Rio de Janeiro city, Brazil, and has a heavy vehicular traffic and intense pedestrian flow. Many pedestrians cross the four lanes of avenue dangerously disobeying the traffic light indications. To conduct this research about pedestrian's behavior at crosswalks, a model known as Communication-Human Information Processing Model - C-HIP Model was used. Investigating the stages by C-HIP model perspective, using methods and techniques for each stage, enabled to identify which factors can contribute to pedestrians to disobey traffic signs and adopt a risky behavior in pedestrian crossing.

  2. 14 CFR 170.13 - Airport Traffic Control Tower (ATCT) establishment criteria.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airport Traffic Control Tower (ATCT... AIR TRAFFIC CONTROL SERVICES AND NAVIGATIONAL FACILITIES Airport Traffic Control Towers § 170.13 Airport Traffic Control Tower (ATCT) establishment criteria. (a) The following criteria along with...

  3. 14 CFR 170.13 - Airport Traffic Control Tower (ATCT) establishment criteria.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airport Traffic Control Tower (ATCT... AIR TRAFFIC CONTROL SERVICES AND NAVIGATIONAL FACILITIES Airport Traffic Control Towers § 170.13 Airport Traffic Control Tower (ATCT) establishment criteria. (a) The following criteria along with...

  4. 14 CFR 170.13 - Airport Traffic Control Tower (ATCT) establishment criteria.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airport Traffic Control Tower (ATCT... AIR TRAFFIC CONTROL SERVICES AND NAVIGATIONAL FACILITIES Airport Traffic Control Towers § 170.13 Airport Traffic Control Tower (ATCT) establishment criteria. (a) The following criteria along with...

  5. A sliding mode controller for vehicular traffic flow

    NASA Astrophysics Data System (ADS)

    Li, Yongfu; Kang, Yuhao; Yang, Bin; Peeta, Srinivas; Zhang, Li; Zheng, Taixong; Li, Yinguo

    2016-11-01

    This study proposes a sliding mode controller for vehicular traffic flow based on a car-following model to enhance the smoothness and stability of traffic flow evolution. In particular, the full velocity difference (FVD) model is used to capture the characteristics of vehicular traffic flow. The proposed sliding mode controller is designed in terms of the error between the desired space headway and the actual space headway. The stability of the controller is guaranteed using the Lyapunov technique. Numerical experiments are used to compare the performance of sliding mode control (SMC) with that of feedback control. The results illustrate the effectiveness of the proposed SMC method in terms of the distribution smoothness and stability of the space headway, velocity, and acceleration profiles. They further illustrate that the SMC strategy is superior to that of the feedback control strategy, while enabling computational efficiency that can aid in practical applications.

  6. Coordinated signal control for arterial intersections using fuzzy logic

    NASA Astrophysics Data System (ADS)

    Kermanian, Davood; Zare, Assef; Balochian, Saeed

    2013-09-01

    Every day growth of the vehicles has become one of the biggest problems of urbanism especially in major cities. This can waste people's time, increase the fuel consumption, air pollution, and increase the density of cars and vehicles. Fuzzy controllers have been widely used in many consumer products and industrial applications with success over the past two decades. This article proposes a comprehensive model of urban traffic network using state space equations and then using Fuzzy Logic Tool Box and SIMULINK Program MATLAB a fuzzy controller in order to optimize and coordinate signal control at two intersections at an arterial road. The fuzzy controller decides to extend, early cut or terminate a signal phase and phase sequence to ensure smooth flow of traffic with minimal waiting time and length of queue. Results show that the performance of the proposed traffic controller at novel fuzzy model is better that of conventional controllers under normal and abnormal traffic conditions.

  7. 10 CFR 431.222 - Definitions concerning traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... convey movement information to pedestrians. Traffic signal module means a standard 8-inch (200 mm) or 12... parts necessary for operation; and (2) Communicates movement messages to drivers through red, amber, and green colors. Test Procedures...

  8. 10 CFR 431.222 - Definitions concerning traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... convey movement information to pedestrians. Traffic signal module means a standard 8-inch (200 mm) or 12... parts necessary for operation; and (2) Communicates movement messages to drivers through red, amber, and green colors. Test Procedures...

  9. 10 CFR 431.222 - Definitions concerning traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... convey movement information to pedestrians. Traffic signal module means a standard 8-inch (200 mm) or 12... parts necessary for operation; and (2) Communicates movement messages to drivers through red, amber, and green colors. Test Procedures...

  10. Taking Over Control From Highly Automated Vehicles in Complex Traffic Situations: The Role of Traffic Density.

    PubMed

    Gold, Christian; Körber, Moritz; Lechner, David; Bengler, Klaus

    2016-06-01

    The aim of this study was to quantify the impact of traffic density and verbal tasks on takeover performance in highly automated driving. In highly automated vehicles, the driver has to occasionally take over vehicle control when approaching system limits. To ensure safety, the ability of the driver to regain control of the driving task under various driving situations and different driver states needs to be quantified. Seventy-two participants experienced takeover situations requiring an evasive maneuver on a three-lane highway with varying traffic density (zero, 10, and 20 vehicles per kilometer). In a between-subjects design, half of the participants were engaged in a verbal 20-Questions Task, representing speaking on the phone while driving in a highly automated vehicle. The presence of traffic in takeover situations led to longer takeover times and worse takeover quality in the form of shorter time to collision and more collisions. The 20-Questions Task did not influence takeover time but seemed to have minor effects on the takeover quality. For the design and evaluation of human-machine interaction in takeover situations of highly automated vehicles, the traffic state seems to play a major role, compared to the driver state, manipulated by the 20-Questions Task. The present results can be used by developers of highly automated systems to appropriately design human-machine interfaces and to assess the driver's time budget for regaining control. © 2016, Human Factors and Ergonomics Society.

  11. Real time network traffic monitoring for wireless local area networks based on compressed sensing

    NASA Astrophysics Data System (ADS)

    Balouchestani, Mohammadreza

    2017-05-01

    A wireless local area network (WLAN) is an important type of wireless networks which connotes different wireless nodes in a local area network. WLANs suffer from important problems such as network load balancing, large amount of energy, and load of sampling. This paper presents a new networking traffic approach based on Compressed Sensing (CS) for improving the quality of WLANs. The proposed architecture allows reducing Data Delay Probability (DDP) to 15%, which is a good record for WLANs. The proposed architecture is increased Data Throughput (DT) to 22 % and Signal to Noise (S/N) ratio to 17 %, which provide a good background for establishing high qualified local area networks. This architecture enables continuous data acquisition and compression of WLAN's signals that are suitable for a variety of other wireless networking applications. At the transmitter side of each wireless node, an analog-CS framework is applied at the sensing step before analog to digital converter in order to generate the compressed version of the input signal. At the receiver side of wireless node, a reconstruction algorithm is applied in order to reconstruct the original signals from the compressed signals with high probability and enough accuracy. The proposed algorithm out-performs existing algorithms by achieving a good level of Quality of Service (QoS). This ability allows reducing 15 % of Bit Error Rate (BER) at each wireless node.

  12. Measurement of Temporal Awareness in Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Rantanen, E.M.

    2009-01-01

    Temporal awareness, or level 3 situation awareness, is critical to successful control of air traffic, yet the construct remains ill-defined and difficult to measure. This research sought evidence for air traffic controllers awareness of temporal characteristics of their tasks in data from a high-fidelity system evaluation simulation. Five teams of controllers worked on four scenarios with different traffic load. Several temporal parameters were defined for each task controllers performed during a simulation run and their actions on the tasks were timed relative to them. Controllers showed a strong tendency to prioritize tasks according to a first come, first served principle. This trend persisted as task load increased. Also evident was awareness of the urgency of tasks, as tasks with impending closing of a window of opportunity were performed before tasks that had longer time available before closing of the window.

  13. Measurement of Temporal Awareness in Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Rantanen, E.M.

    2009-01-01

    Temporal awareness, or level 3 situation awareness, is critical to successful control of air traffic, yet the construct remains ill-defined and difficult to measure. This research sought evidence for air traffic controllers awareness of temporal characteristics of their tasks in data from a high-fidelity system evaluation simulation. Five teams of controllers worked on four scenarios with different traffic load. Several temporal parameters were defined for each task controllers performed during a simulation run and their actions on the tasks were timed relative to them. Controllers showed a strong tendency to prioritize tasks according to a first come, first served principle. This trend persisted as task load increased. Also evident was awareness of the urgency of tasks, as tasks with impending closing of a window of opportunity were performed before tasks that had longer time available before closing of the window.

  14. Supporting the Future Air Traffic Control Projection Process

    NASA Technical Reports Server (NTRS)

    Davison, Hayley J.; Hansman, R. John, Jr.

    2002-01-01

    In air traffic control, projecting what the air traffic situation will be over the next 30 seconds to 30 minutes is a key process in identifying conflicts that may arise so that evasive action can be taken upon discovery of these conflicts. A series of field visits in the Boston and New York terminal radar approach control (TRACON) facilities and in the oceanic air traffic control facilities in New York and Reykjavik, Iceland were conducted to investigate the projection process in two different ATC domains. The results from the site visits suggest that two types of projection are currently used in ATC tasks, depending on the type of separation minima and/or traffic restriction and information display used by the controller. As technologies improve and procedures change, care should be taken by designers to support projection through displays, automation, and procedures. It is critical to prevent time/space mismatches between interfaces and restrictions. Existing structure in traffic dynamics could be utilized to provide controllers with useful behavioral models on which to build projections. Subtle structure that the controllers are unable to internalize could be incorporated into an ATC projection aid.

  15. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 23 Highways 1 2013-04-01 2013-04-01 false Maintenance of temporary traffic control devices. 630... AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Temporary Traffic Control Devices § 630.1110 Maintenance of temporary traffic control devices. To provide for the continued effectiveness of...

  16. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Maintenance of temporary traffic control devices. 630... AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Temporary Traffic Control Devices § 630.1110 Maintenance of temporary traffic control devices. To provide for the continued effectiveness of...

  17. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Maintenance of temporary traffic control devices. 630... AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Temporary Traffic Control Devices § 630.1110 Maintenance of temporary traffic control devices. To provide for the continued effectiveness of...

  18. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Maintenance of temporary traffic control devices. 630... AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Temporary Traffic Control Devices § 630.1110 Maintenance of temporary traffic control devices. To provide for the continued effectiveness of...

  19. Symmetry breaking in optimal timing of traffic signals on an idealized two-way street

    NASA Astrophysics Data System (ADS)

    Panaggio, Mark J.; Ottino-Löffler, Bertand J.; Hu, Peiguang; Abrams, Daniel M.

    2013-09-01

    Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this “green-wave” scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

  20. Identification of traffic accident risk-prone areas under low-light conditions

    NASA Astrophysics Data System (ADS)

    Ivan, K.; Haidu, I.; Benedek, J.; Ciobanu, S. M.

    2015-09-01

    Besides other non-behavioural factors, low-light conditions significantly influence the frequency of traffic accidents in an urban environment. This paper intends to identify the impact of low-light conditions on traffic accidents in the city of Cluj-Napoca, Romania. The dependence degree between light and the number of traffic accidents was analysed using the Pearson correlation, and the relation between the spatial distribution of traffic accidents and the light conditions was determined by the frequency ratio model. The vulnerable areas within the city were identified based on the calculation of the injury rate for the 0.5 km2 areas uniformly distributed within the study area. The results show a strong linear correlation between the low-light conditions and the number of traffic accidents in terms of three seasonal variations and a high probability of traffic accident occurrence under the above-mentioned conditions at the city entrances/exits, which represent vulnerable areas within the study area. Knowing the linear dependence and the spatial relation between the low light and the number of traffic accidents, as well as the consequences induced by their occurrence, enabled us to identify the areas of high traffic accident risk in Cluj-Napoca.

  1. Identification of traffic accident risk-prone areas under low lighting conditions

    NASA Astrophysics Data System (ADS)

    Ivan, K.; Haidu, I.; Benedek, J.; Ciobanu, S. M.

    2015-02-01

    Besides other non-behavioural factors, the low lighting conditions significantly influence the frequency of the traffic accidents in the urban environment. This paper intends to identify the impact of low lighting conditions on the traffic accidents in the city of Cluj-Napoca. The dependence degree between lighting and the number of traffic accidents was analyzed by the Pearson's correlation and the relation between the spatial distribution of traffic accidents and the lighting conditions was determined by the frequency ratio model. The vulnerable areas within the city were identified based on the calculation of the injured persons rate for the 0.5 km2 equally-sized areas uniformly distributed within the study area. The results have shown a strong linear dependence between the low lighting conditions and the number of traffic accidents in terms of three seasonal variations and a high probability of traffic accidents occurrence under the above-mentioned conditions, at the city entrances-exits, which represent also vulnerable areas within the study area. Knowing the linear dependence and the spatial relation between the low lighting and the number of traffic accidents, as well as the consequences induced by their occurrence enabled us to identify the high traffic accident risk areas in the city of Cluj-Napoca.

  2. Surveying air traffic control specialist perception of scheduling regulations

    NASA Astrophysics Data System (ADS)

    Thompson, Darrius E.

    While there have been several studies conducted on air traffic controller fatigue, there is a lack of research on the subject since the scheduling policy changes that took place in 2012. The effectiveness of these changes has yet to be measured. The goal of this study was to investigate air traffic control specialist views towards the number of hours scheduled between shifts, changes in perception since 2012 regulation changes, and external factors that impact fatigue. A total of 54 FAA air traffic control specialist completed an online questionnaire. The results from the survey showed that the majority of respondents felt the 2012 regulation changes were not sufficient to address fatigue issues, and work with some amount sleep deprivation. The factors that appeared to have the most significant effect on fatigue included facility level, age group, availability of recuperative breaks, and children under 18 in the home.

  3. 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.

  4. Human factors in air traffic control: problems at the interfaces.

    PubMed

    Shouksmith, George

    2003-10-01

    The triangular ISIS model for describing the operation of human factors in complex sociotechnical organisations or systems is applied in this research to a large international air traffic control system. A large sample of senior Air Traffic Controllers were randomly assigned to small focus discussion groups, whose task was to identify problems occurring at the interfaces of the three major human factor components: individual, system impacts, and social. From these discussions, a number of significant interface problems, which could adversely affect the functioning of the Air Traffic Control System, emerged. The majority of these occurred at the Individual-System Impact and Individual-Social interfaces and involved a perceived need for further interface centered training.

  5. Cognitive Task Analysis of Prioritization in Air Traffic Control.

    ERIC Educational Resources Information Center

    Redding, Richard E.; And Others

    A cognitive task analysis was performed to analyze the key cognitive components of the en route air traffic controllers' jobs. The goals were to ascertain expert mental models and decision-making strategies and to identify important differences in controller knowledge, skills, and mental models as a function of expertise. Four groups of…

  6. 47 CFR 2.402 - Control of distress traffic.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Control of distress traffic. 2.402 Section 2.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Distress, Disaster, and Emergency Communications § 2.402 Control...

  7. 47 CFR 2.402 - Control of distress traffic.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Control of distress traffic. 2.402 Section 2.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Distress, Disaster, and Emergency Communications § 2.402 Control...

  8. 47 CFR 2.402 - Control of distress traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Control of distress traffic. 2.402 Section 2.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Distress, Disaster, and Emergency Communications § 2.402 Control...

  9. 47 CFR 2.402 - Control of distress traffic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Control of distress traffic. 2.402 Section 2.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Distress, Disaster, and Emergency Communications § 2.402 Control...

  10. 47 CFR 2.402 - Control of distress traffic.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Control of distress traffic. 2.402 Section 2.402 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY ALLOCATIONS AND RADIO TREATY MATTERS; GENERAL RULES AND REGULATIONS Distress, Disaster, and Emergency Communications § 2.402 Control...

  11. Teaching Guide for the Traffic Signal Light Program: Kindergarten Level.

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore.

    This teachers' guide provides materials and suggestions for approximately 125 lessons that are designed to increase kindergarten children's traffic safety skills and knowledge. Most of the guide focuses on (1) lessons about physical structures in the pedestrian environment such as sidewalks, curbs, crosswalks, and intersections, and (2) signal…

  12. Road crossing behavior under traffic light conflict: Modulating effects of green light duration and signal congruency.

    PubMed

    Lange, Florian; Haiduk, Michael; Boos, Moritz; Tinschert, Peter; Schwarze, Anke; Eggert, Frank

    2016-10-01

    A large number of pedestrians and cyclists regularly ignore the traffic lights to cross the road illegally. In a recent analysis, illegal road crossing behavior has been shown to be enhanced in the presence of incongruent stimulus configurations. Pedestrians and cyclists are more likely to cross against a red light when exposed to an irrelevant conflicting green light. Here, we present experimental and observational data on the factors moderating the risk associated with incongruent traffic lights. In an observational study, we demonstrated that the conflict-related increase in illegal crossing rates is reduced when pedestrian and cyclist green light periods are long. In a laboratory experiment, we manipulated the color of the irrelevant signals to expose participants to different degrees of incongruency. Results revealed that individuals' performance gradually varied as a function of incongruency, suggesting that the negative impact of a conflicting green light can be reduced by slightly adjusting its color. Our findings highlight that the observation of real-world behavior at intersections and the experimental analysis of psychological processes under controlled laboratory conditions can complement each other in identifying risk factors of risky road crossing behavior. Based on this combination, our study elaborates on promising measures to improve safety at signalized intersections. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Traffic behavior of mixed traffic flow with two kinds of different self-stabilizing control vehicles

    NASA Astrophysics Data System (ADS)

    Li, Zhipeng; Li, Wenzhong; Xu, Shangzhi; Qian, Yeqing; Sun, Jian

    2015-10-01

    In this paper, we propose a heterogeneous car following model in terms of an extension to the original optimal velocity model characterizing two classes of different self-stabilizing control vehicles. Linear stability analysis method is utilized to the extended model, for purpose to explore how the varying percentages of the vehicles with short-duration self-stabilizing control influence the stability of the heterogeneous traffic flow. We obtain the neutral stability lines for different percentages of two classes of vehicles, with finding that the traffic flow trends to stable with the decrease of the percentage for short-duration self-stabilizing control vehicles. Moreover, we explore a special case that the same numbers of two different classes of vehicles with self-stabilizing control. We theoretically derive the stability condition of the special case, and conclude the effect of the average value and the standard deviation of two time gaps, on the heterogeneous traffic stability. At last, direct simulations are conducted to verify the conclusion of theoretical analysis.

  14. Procedural errors in air traffic control: effects of traffic density, expertise, and automation.

    PubMed

    Di Nocera, Francesco; Fabrizi, Roberto; Terenzi, Michela; Ferlazzo, Fabio

    2006-06-01

    Air traffic management requires operators to frequently shift between multiple tasks and/or goals with different levels of accomplishment. Procedural errors can occur when a controller accomplishes one of the tasks before the entire operation has been completed. The present study had two goals: first, to verify the occurrence of post-completion errors in air traffic control (ATC) tasks; and second, to assess effects on performance of medium term conflict detection (MTCD) tools. There were 18 military controllers who performed a simulated ATC task with and without automation support (MTCD vs. manual) in high and low air traffic density conditions. During the task, which consisted of managing several simulated flights in an enroute ATC scenario, a trace suddenly disappeared "after" the operator took the aircraft in charge, "during" the management of the trace, or "before" the pilot's first contact. In the manual condition, only the fault type "during" was found to be significantly different from the other two. On the contrary, when in the MTCD condition, the fault type "after" generated significantly less errors than the fault type "before." Additionally, automation was found to affect performance of junior controllers, whereas seniors' performance was not affected. Procedural errors can happen in ATC, but automation can mitigate this effect. Lack of benefits for the "before" fault type may be due to the fact that operators extend their reliance to a part of the task that is unsupported by the automated system.

  15. Critical review of heavy metal pollution of traffic area runoff: Occurrence, influencing factors, and partitioning.

    PubMed

    Huber, Maximilian; Welker, Antje; Helmreich, Brigitte

    2016-01-15

    A dataset of 294 monitored sites from six continents (Africa, Asia, Australia, Europe, North and South America) was compiled and evaluated to characterize the occurrence and fate of heavy metals in eight traffic area categories (parking lots, bridges, and three types each of both roads and highways). In addition, site-specific (fixed and climatic) and method-specific (related to sample collection, preparation, and analysis) factors that influence the results of the studies are summarized. These factors should be considered in site descriptions, conducting monitoring programs, and implementing a database for further research. Historical trends for Pb show a sharp decrease during recent decades, and the median total Pb concentrations of the 21st century for North America and Europe are approximately 15 μg/L. No historical trend is detected for Zn. Zn concentrations are very variable in traffic area runoff compared with other heavy metals because of its presence in galvanized structures and crumbs of car tire rubber. Heavy metal runoff concentrations of parking lots differ widely according to their use (e.g., employee, supermarket, rest areas for trucks). Bridge deck runoff can contain high Zn concentrations from safety fences and galvanizing elements. Roads with more than 5000 vehicles per day are often more polluted than highways because of other site-specific factors such as traffic signals. Four relevant heavy metals (Zn, Cu, Ni, and Cd) can occur in the dissolved phase. Knowledge of metal partitioning is important to optimize stormwater treatment strategies and prevent toxic effects to organisms in receiving waters.

  16. The Effectiveness of Yoga on Spiritual Intelligence in Air Traffic Controllers of Tehran Flight Control Center

    ERIC Educational Resources Information Center

    Safara, Maryam; Ghasemi, Pejman

    The aim of this study was to evaluate the efficacy of yoga on spiritual intelligence in air traffic controllers in Tehran flight control center. This was a quasi-experimental research and the study population includes all air traffic controllers in Tehran flight control center. The sample consisted of 40 people of the study population that were…

  17. Automated mixed traffic vehicle control and scheduling study

    NASA Technical Reports Server (NTRS)

    Peng, T. K. C.; Chon, K.

    1976-01-01

    The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

  18. A chemometric investigation of aromatic emission profiles from a marine engine in comparison with residential wood combustion and road traffic: Implications for source apportionment inside and outside sulphur emission control areas

    NASA Astrophysics Data System (ADS)

    Czech, Hendryk; Stengel, Benjamin; Adam, Thomas; Sklorz, Martin; Streibel, Thorsten; Zimmermann, Ralf

    2017-10-01

    Ship emissions are known to cause severe impacts on human health, but are less restricted than land-based emissions. A regulation to improve air quality in coastal regions and frequented waterways is the limitation of fuel sulphur content to 0.1% in sulphur emission control areas (SECAs), which has caused a switch from heavy fuel oil (HFO) towards diesel-like marine gas oil (MGO) or marine diesel oil (MDO). The fraction of aromatic organic vapours in the exhaust from a marine engine, operating on HFO and MGO, was investigated by resonance-enhanced multi-photon ionisation time-of-flight mass spectrometry (REMPI-TOFMS). MGO with fuel sulphur content (FSC) below 0.1% and HFO with an average FSC of 2.7% denote representative marine fuels inside and outside SECAs, respectively. The obtained emission spectra were combined with data of previous REMPI-TOFMS studies of combustion engines and wood combustion in statistical analyses to derive marker substances for ship emissions inside and outside SECAs. A diagnostic ratio of C2-naphthalenes to methyl-naphthalenes was found to hold for a good discriminator between ship emissions on the one hand and road traffic and wood combustion on the other hand. Furthermore, random REMPI spectra from all emission sources were mixed with different proportions in a simulation to create a model based on partial least square (PLS) regression for the prediction of ship contribution to aromatic organic vapours. We point out that in particular PAHs with higher degree of alkylation are significant markers for primary ship emissions which may support source apportionment studies inside and outside SECAs to assess the benefits of fuel sulphur content regulation on air quality.

  19. 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.

  20. Engineering modeling of traffic noise in shielded areas in cities.

    PubMed

    Salomons, Erik M; Polinder, Henk; Lohman, Walter J A; Zhou, Han; Borst, Hieronymous C; Miedema, Henk M E

    2009-11-01

    A computational study of road traffic noise in cities is presented. Based on numerical boundary-element calculations of canyon-to-canyon propagation, an efficient engineering algorithm is developed to calculate the effect of multiple reflections in street canyons. The algorithm is supported by a room-acoustical analysis of the reverberant sound fields in the source and receiver canyons. Using the algorithm, a simple model for traffic noise in cities is developed. Noise maps and exposure distributions of the city of Amsterdam are calculated with the model, and for comparison also with an engineering model that is currently used for traffic noise impact assessments in cities. Considerable differences between the two model predictions are found for shielded buildings with day-evening-night levels of 40-60 dB at the facades. Further, an analysis is presented of level differences between the most and the least exposed facades of buildings. Large level differences are found for buildings directly exposed to traffic noise from nearby roads. It is shown that by a redistribution of traffic flow around these buildings, one can achieve low sound levels at quiet sides and a corresponding reduction in the percentage of highly annoyed inhabitants from typically 23% to 18%.

  1. Human factors measurement for future air traffic control systems.

    PubMed

    Langan-Fox, Janice; Sankey, Michael J; Canty, James M

    2009-10-01

    This article provides a critical review of research pertaining to the measurement of human factors (HF) issues in current and future air traffic control (ATC). Growing worldwide air traffic demands call for a radical departure from current ATC systems. Future systems will have a fundamental impact on the roles and responsibilities of ATC officers (ATCOs). Valid and reliable methods of assessing HF issues associated with these changes, such as a potential increase (or decrease) in workload, are of utmost importance for advancing theory and for designing systems, procedures, and training. We outline major aviation changes and how these relate to five key HF issues in ATC. Measures are outlined, compared, and evaluated and are followed by guidelines for assessing these issues in the ATC domain. Recommendations for future research are presented. A review of the literature suggests that situational awareness and workload have been widely researched and assessed using a variety of measures, but researchers have neglected the areas of trust, stress, and boredom. We make recommendations for use of particular measures and the construction of new measures. It is predicted that, given the changing role of ATCOs and profound future airspace requirements and configurations, issues of stress, trust, and boredom will become more significant. Researchers should develop and/or refine existing measures of all five key HF issues to assess their impact on ATCO performance. Furthermore, these issues should be considered in a holistic manner. The current article provides an evaluation of research and measures used in HF research on ATC that will aid research and ATC measurement.

  2. Traffic control devices, visibility, and railroad grade crossings. Transportation research record

    SciTech Connect

    1995-12-31

    The papers contained in this volume are primarily from the 74th Annual Meeting of the Transportation Research Board and the Symposium for Improving Visibility for the Night Traveler, which was held in May 1994 in Washington, D.C. They concern traffic signs and signals, highway visibility, and rail-highway grade crossing safety and research, addressing some of the problems and issues facing urban engineers as they grapple with the ever more complex traffic system. Readers with a specific interest in traffic control devices will find papers related to effective uses of variable message signs, comprehension of various types of traffic control devices and their effects on driver behavior, pedestrian crosswalk time requirements, and empirical analysis of two-way stop-controlled intersections. Readers with an interest in delineation and illumination will find papers on minimum retroreflectivity requirements, pavement marking visibility and detectability, curve delineation, traffic sign reading distances at night, and apparent nighttime color of pavement marking products. Closing out this Record are papers addressing the application of GIS to rail-highway crossing safety and the accuracy of U.S. Department of Transportation rail-highway grade crossing accident prediction models.

  3. Predicting Human Error in Air Traffic Control Decision Support Tools and Free Flight Concepts

    NASA Technical Reports Server (NTRS)

    Mogford, Richard; Kopardekar, Parimal

    2001-01-01

    The document is a set of briefing slides summarizing the work the Advanced Air Transportation Technologies (AATT) Project is doing on predicting air traffic controller and airline pilot human error when using new decision support software tools and when involved in testing new air traffic control concepts. Previous work in this area is reviewed as well as research being done jointly with the FAA. Plans for error prediction work in the AATT Project are discussed. The audience is human factors researchers and aviation psychologists from government and industry.

  4. Predicting Human Error in Air Traffic Control Decision Support Tools and Free Flight Concepts

    NASA Technical Reports Server (NTRS)

    Mogford, Richard; Kopardekar, Parimal

    2001-01-01

    The document is a set of briefing slides summarizing the work the Advanced Air Transportation Technologies (AATT) Project is doing on predicting air traffic controller and airline pilot human error when using new decision support software tools and when involved in testing new air traffic control concepts. Previous work in this area is reviewed as well as research being done jointly with the FAA. Plans for error prediction work in the AATT Project are discussed. The audience is human factors researchers and aviation psychologists from government and industry.

  5. Stability analysis of traffic flow with extended CACC control models

    NASA Astrophysics Data System (ADS)

    Ya-Zhou, Zheng; Rong-Jun, Cheng; Siu-Ming, Lo; Hong-Xia, Ge

    2016-06-01

    To further investigate car-following behaviors in the cooperative adaptive cruise control (CACC) strategy, a comprehensive control system which can handle three traffic conditions to guarantee driving efficiency and safety is designed by using three CACC models. In this control system, some vital comprehensive information, such as multiple preceding cars’ speed differences and headway, variable safety distance (VSD) and time-delay effect on the traffic current and the jamming transition have been investigated via analytical or numerical methods. Local and string stability criterion for the velocity control (VC) model and gap control (GC) model are derived via linear stability theory. Numerical simulations are conducted to study the performance of the simulated traffic flow. The simulation results show that the VC model and GC model can improve driving efficiency and suppress traffic congestion. Project supported by the National Natural Science Foundation of China (Grant Nos. 71571107 and 11302110). The Scientific Research Fund of Zhejiang Province, China (Grant Nos. LY15A020007, LY15E080013, and LY16G010003). The Natural Science Foundation of Ningbo City (Grant Nos. 2014A610030 and 2015A610299), the Fund from the Government of the Hong Kong Administrative Region, China (Grant No. CityU11209614), and the K C Wong Magna Fund in Ningbo University, China.

  6. 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.

  7. Signal optimization in urban transport: A totally asymmetric simple exclusion process with traffic lights

    NASA Astrophysics Data System (ADS)

    Arita, Chikashi; Foulaadvand, M. Ebrahim; Santen, Ludger

    2017-03-01

    We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.

  8. Signal optimization in urban transport: A totally asymmetric simple exclusion process with traffic lights.

    PubMed

    Arita, Chikashi; Foulaadvand, M Ebrahim; Santen, Ludger

    2017-03-01

    We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.

  9. Driver behaviour at rail level crossings: responses to flashing lights, traffic signals and stop signs in simulated rural driving.

    PubMed

    Lenné, Michael G; Rudin-Brown, Christina M; Navarro, Jordan; Edquist, Jessica; Trotter, Margaret; Tomasevic, Nebojsa

    2011-05-01

    Australian road and railway authorities have made a concerted effort to reduce the number of rail level crossings, particularly the higher risk passive crossings that are protected by devices such as 'give way' or 'stop' signs. To improve this situation, passive level crossings are often upgraded with active controls such as flashing red lights. Traffic signals may provide good safety outcomes at level crossings but remain untested. The primary purpose of this research was to compare driver behaviour at two railway level crossings with active controls, flashing red lights and traffic signals, to behaviour at the current standard passive level crossing control, a stop sign. Participants drove the MUARC advanced driving simulator for 30 min. During the simulated drive, participants were exposed to three level crossing scenarios. Each scenario consisted of one of three level crossing control types, and was associated with an oncoming train. Mean vehicle speed on approach to the level crossings decreased more rapidly in response to flashing lights than to traffic signals. While speed on approach was lowest for the stop-sign condition, the number of non-compliant drivers (i.e., those who did not stop) at the crossing was highest for this condition. While results indicate that traffic signals at rail level crossings do not appear to offer any safety benefits over and above flashing red lights, further avenues of research are proposed to reach more definitive conclusions. Compliance was lowest for the passive crossing control which provides further support for the ongoing passive crossing upgrades in Australia. Copyright © 2010 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Initial Air Traffic Control Training at Tartu Aviation College.

    ERIC Educational Resources Information Center

    Kulbas, Tanel

    1997-01-01

    Development of an air traffic control (ATC) training course at Tartu Aviation College in Estonia had to start at ground zero, creating new rules and regulations for ATC, writing special study materials, building simulators, and finding enough applicants with sufficient English skills. (SK)

  11. Trainer Interventions as Instructional Strategies in Air Traffic Control Training

    ERIC Educational Resources Information Center

    Koskela, Inka; Palukka, Hannele

    2011-01-01

    Purpose: This paper aims to identify methods of guidance and supervision used in air traffic control training. It also aims to show how these methods facilitate trainee participation in core work activities. Design/methodology/approach: The paper applies the tools of conversation analysis and ethnomethodology to explore the ways in which trainers…

  12. Planes, Politics and Oral Proficiency: Testing International Air Traffic Controllers

    ERIC Educational Resources Information Center

    Moder, Carol Lynn; Halleck, Gene B.

    2009-01-01

    This study investigates the variation in oral proficiency demonstrated by 14 Air Traffic Controllers across two types of testing tasks: work-related radio telephony-based tasks and non-specific English tasks on aviation topics. Their performance was compared statistically in terms of level ratings on the International Civil Aviation Organization…

  13. Trainer Interventions as Instructional Strategies in Air Traffic Control Training

    ERIC Educational Resources Information Center

    Koskela, Inka; Palukka, Hannele

    2011-01-01

    Purpose: This paper aims to identify methods of guidance and supervision used in air traffic control training. It also aims to show how these methods facilitate trainee participation in core work activities. Design/methodology/approach: The paper applies the tools of conversation analysis and ethnomethodology to explore the ways in which trainers…

  14. Initial Air Traffic Control Training at Tartu Aviation College.

    ERIC Educational Resources Information Center

    Kulbas, Tanel

    1997-01-01

    Development of an air traffic control (ATC) training course at Tartu Aviation College in Estonia had to start at ground zero, creating new rules and regulations for ATC, writing special study materials, building simulators, and finding enough applicants with sufficient English skills. (SK)

  15. Second Careers: The Air Traffic Controller Experience and Beyond.

    ERIC Educational Resources Information Center

    Batten, Michael D.

    1978-01-01

    Second careers are examined from an organizational viewpoint, and new directions for education-work policy, suggested by a unique second career program of the Federal Aviation Administration for air traffic controllers, are explored. Focus is on age, organizational and training factors, and community involvement. (Author/JMD)

  16. Planes, Politics and Oral Proficiency: Testing International Air Traffic Controllers

    ERIC Educational Resources Information Center

    Moder, Carol Lynn; Halleck, Gene B.

    2009-01-01

    This study investigates the variation in oral proficiency demonstrated by 14 Air Traffic Controllers across two types of testing tasks: work-related radio telephony-based tasks and non-specific English tasks on aviation topics. Their performance was compared statistically in terms of level ratings on the International Civil Aviation Organization…

  17. Impact of Cooperative Learning on Naval Air Traffic Controller Training.

    ERIC Educational Resources Information Center

    Holubec, Edythe; And Others

    1993-01-01

    Reports on a study of the impact of cooperative learning techniques, compared with traditional Navy instructional methods, on Navy air traffic controller trainees. Finds that cooperative learning methods improved higher level reasoning skills and resulted in no failures among the trainees. (CFR)

  18. Optimization of congested traffic by controlling stop-and-go waves.

    PubMed

    Tomer, Elad; Safonov, Leonid; Madar, Nilly; Havlin, Shlomo

    2002-06-01

    We propose a new optimization strategy based on inducing stop-and-go waves on the main road and controlling their wavelength. Using numerical simulations of a recent stochastic car-following model we show that this strategy yields optimization of traffic flow when implemented in systems with a localized periodic inhomogeneity, such as signalized intersections and entry ramps. The optimization process is explained by our finding of a generalized fundamental diagram (GFD) for traffic, namely a flux-density-wavelength relation. Projecting the GFD on the density-flux plane yields a two-dimensional region of stable states, qualitatively similar to that found empirically [Kerner, Phys. Rev. Lett. 81, 3797 (1998)] in synchronized traffic.

  19. Development of simulation techniques suitable for the analysis of air traffic control situations and instrumentation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A terminal area simulation is described which permits analysis and synthesis of current and advanced air traffic management system configurations including ground and airborne instrumentation and new and modified aircraft characteristics. Ground elements in the simulation include navigation aids, surveillance radars, communication links, air-route structuring, ATC procedures, airport geometries and runway handling constraints. Airborne elements include traffic samples with individual aircraft performance and operating characteristics and aircraft navigation equipment. The simulation also contains algorithms for conflict detection, conflict resolution, sequencing and pilot-controller data links. The simulation model is used to determine the sensitivities of terminal area traffic flow, safety and congestion to aircraft performance characteristics, avionics systems, and other ATC elements.

  20. Intelligent Control in Automation Based on Wireless Traffic Analysis

    SciTech Connect

    Kurt Derr; Milos Manic

    2007-08-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  1. Intelligent Control in Automation Based on Wireless Traffic Analysis

    SciTech Connect

    Kurt Derr; Milos Manic

    2007-09-01

    Wireless technology is a central component of many factory automation infrastructures in both the commercial and government sectors, providing connectivity among various components in industrial realms (distributed sensors, machines, mobile process controllers). However wireless technologies provide more threats to computer security than wired environments. The advantageous features of Bluetooth technology resulted in Bluetooth units shipments climbing to five million per week at the end of 2005 [1, 2]. This is why the real-time interpretation and understanding of Bluetooth traffic behavior is critical in both maintaining the integrity of computer systems and increasing the efficient use of this technology in control type applications. Although neuro-fuzzy approaches have been applied to wireless 802.11 behavior analysis in the past, a significantly different Bluetooth protocol framework has not been extensively explored using this technology. This paper presents a new neurofuzzy traffic analysis algorithm of this still new territory of Bluetooth traffic. Further enhancements of this algorithm are presented along with the comparison against the traditional, numerical approach. Through test examples, interesting Bluetooth traffic behavior characteristics were captured, and the comparative elegance of this computationally inexpensive approach was demonstrated. This analysis can be used to provide directions for future development and use of this prevailing technology in various control type applications, as well as making the use of it more secure.

  2. Final Environmental Assessment, Construction and Operation of Air Traffic Control Tower

    DTIC Science & Technology

    2008-05-12

    Existing Control Tower Site. Complete demolition of the Control Tower building on the site would produce waste concrete, asphalt , metal, and wood...Construction & Operation of Air Traffic Control Tower 44 May 12, 2008 receptor elements. Workers would wear ear protection, as necessary, for...appear to be achieving their hazardous waste reduction goals. The major areas not meeting goals appear to be abrasive blasting and industrial

  3. The Impact of a Traffic Alert and Collision Avoidance System on the Air Traffic Control Radar Beacon System and Mode S System in the Los Angeles Basin.

    DTIC Science & Technology

    1985-05-01

    FAAIPM-84130 The Impact of a Traffic Alert and Program Engineering Collision Avoidance System on the and Maintenance Service Air Traffic Control Radar...ON4 THE AIR TRAFFIC CONTROL RADAR BEACON SYSTEM 6.~ eforming organization Cede AND THE MODE :3 SYSTEM IN THE LOS ANGELES BASIN P032 7 A~,re~lIS...performed to predict the impact of the Traffic Alert and Collision Avoidance System (TCAS) on the performance of selected air traffic control and surveil

  4. Adaptive Neural Network Controller for ATM Traffic

    DTIC Science & Technology

    1996-12-01

    IEEE Communications Magazine (October 1995). 2. Baum, Eric B...Adaptive Control in ATM Networks," IEEE Communications Magazine (October 1995). 9. Evanowsky, John B. "Information for the Warrior," IEEE Communications Magazine (October...Network Applications in ATM," IEEE Communications Magazine (October 1995). 78 16. Imrich, et al. "A counter based congestion control for ATM

  5. Four-dimensional guidance problem with control delays. [in air traffic control automation

    NASA Technical Reports Server (NTRS)

    Nagarajan, N.

    1976-01-01

    This paper, assuming steady wind and zero sideslip, presents a discrete-time mathematical model to obtain a control law and three-dimensional flight path to guide an aircraft in a given time from a given initial state (position, velocity and heading) to a prescribed final state subject to the constraints on airspeed acceleration, and pitch and bank angles of the aircraft. For ease in implementing the control law, the control inputs are assumed to be delayed and are applied in a sequential fashion. The guidance problem is formulated as a discrete nonlinear optimal control problem with time delays in dynamics and a cost functional of Bolza form. With a quadratic penalty function to handle terminal constraints on velocity and heading, a solution technique to the control problem based on conjugate gradient algorithm is investigated. Numerical examples are presented to illustrate the applicability of this approach to solution of a terminal area guidance problem in an automated air traffic control environment.

  6. Simulating Human Cognition in the Domain of Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Freed, Michael; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    Experiments intended to assess performance in human-machine interactions are often prohibitively expensive, unethical or otherwise impractical to run. Approximations of experimental results can be obtained, in principle, by simulating the behavior of subjects using computer models of human mental behavior. Computer simulation technology has been developed for this purpose. Our goal is to produce a cognitive model suitable to guide the simulation machinery and enable it to closely approximate a human subject's performance in experimental conditions. The described model is designed to simulate a variety of cognitive behaviors involved in routine air traffic control. As the model is elaborated, our ability to predict the effects of novel circumstances on controller error rates and other performance characteristics should increase. This will enable the system to project the impact of proposed changes to air traffic control procedures and equipment on controller performance.

  7. Simulating Human Cognition in the Domain of Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Freed, Michael; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    Experiments intended to assess performance in human-machine interactions are often prohibitively expensive, unethical or otherwise impractical to run. Approximations of experimental results can be obtained, in principle, by simulating the behavior of subjects using computer models of human mental behavior. Computer simulation technology has been developed for this purpose. Our goal is to produce a cognitive model suitable to guide the simulation machinery and enable it to closely approximate a human subject's performance in experimental conditions. The described model is designed to simulate a variety of cognitive behaviors involved in routine air traffic control. As the model is elaborated, our ability to predict the effects of novel circumstances on controller error rates and other performance characteristics should increase. This will enable the system to project the impact of proposed changes to air traffic control procedures and equipment on controller performance.

  8. Effect of Dynamic Sector Boundary Changes on Air Traffic Controllers

    NASA Technical Reports Server (NTRS)

    Jung, Jaewoo; Lee, Paul; Kessell, Angela; Homola, Jeff; Zelinski, Shannon

    2010-01-01

    The effect of dynamic sector boundary changes on air traffic controller workload was investigated with data from a human-in-the-loop simulation. Multiple boundary changes were made during simulated operations, and controller rating of workload was recorded. Analysis of these data showed an increase of 16.9% in controller workload due to boundary changes. This increased workload was correlated with the number of aircraft handoffs and change in sector volume. There was also a 12.7% increase in average workload due to the changed sector design after boundary changes. This increase was correlated to traffic flow crossing points getting closer to sector boundaries and an increase in the number of flights with short dwell time in a sector. This study has identified some of the factors that affect controller workload when sector boundaries are changed, but more research is needed to better understand their relationships.

  9. Individual Markers of Resilience in Train Traffic Control

    PubMed Central

    Lo, Julia C.; Pluyter, Kari R.; Meijer, Sebastiaan A.

    2015-01-01

    Objective: The aim of this study was to examine individual markers of resilience and obtain quantitative insights into the understanding and the implications of variation and expertise levels in train traffic operators’ goals and strategic mental models and their impact on performance. Background: The Dutch railways are one of the world’s most heavy utilized railway networks and have been identified to be weak in system and organizational resilience. Method: Twenty-two train traffic controllers enacted two scenarios in a human-in-the-loop simulator. Their experience, goals, strategic mental models, and performance were assessed through questionnaires and simulator logs. Goals were operationalized through performance indicators and strategic mental models through train completion strategies. Results: A variation was found between operators for both self-reported primary performance indicators and completion strategies. Further, the primary goal of only 14% of the operators reflected the primary organizational goal (i.e., arrival punctuality). An incongruence was also found between train traffic controllers’ self-reported performance indicators and objective performance in a more disrupted condition. The level of experience tends to affect performance differently. Conclusion: There is a gap between primary organizational goals and preferred individual goals. Further, the relative strong diversity in primary operator goals and strategic mental models indicates weak resilience at the individual level. Application: With recent and upcoming large-scale changes throughout the sociotechnical space of the railway infrastructure organization, the findings are useful to facilitate future railway traffic control and the development of a resilient system. PMID:26721290

  10. Conflict-free trajectory planning for air traffic control automation

    NASA Technical Reports Server (NTRS)

    Slattery, Rhonda; Green, Steve

    1994-01-01

    As the traffic demand continues to grow within the National Airspace System (NAS), the need for long-range planning (30 minutes plus) of arrival traffic increases greatly. Research into air traffic control (ATC) automation at ARC has led to the development of the Center-TRACON Automation System (CTAS). CTAS determines optimum landing schedules for arrival traffic and assists controllers in meeting those schedules safely and efficiently. One crucial element in the development of CTAS is the capability to perform long-range (20 minutes) and short-range (5 minutes) conflict prediction and resolution once landing schedules are determined. The determination of conflict-free trajectories within the Center airspace is particularly difficult because of large variations in speed and altitude. The paper describes the current design and implementation of the conflict prediction and resolution tools used to generate CTAS advisories in Center airspace. Conflict criteria (separation requirements) are defined and the process of separation prediction is described. The major portion of the paper will describe the current implementation of CTAS conflict resolution algorithms in terms of the degrees of freedom for resolutions as well as resolution search techniques. The tools described in this paper have been implemented in a research system designed to rapidly develop and evaluate prototype concepts and will form the basis for an operational ATC automation system.

  11. Scenarios for Evolution of Air Traffic Control,

    DTIC Science & Technology

    1981-11-01

    computer hardware and software technology now promise greater automation of the ATC process and a significantly different role for the controller. This...loop, it requires virtually perfect software and a complex fail-safe de- sign. If AERA can be realized, its limited domain of applicability and V.V Vi...tactical communications management software system would enable controllers to store planned clearances for later automatic delivery. Strategic and tactical

  12. Road traffic nuisance in residential and commercial areas.

    PubMed

    Williams, I D; McCrae, I S

    1995-07-08

    Air pollution from traffic is one of the main factors considered in the environmental appraisal of road schemes. Currently this appraisal concentrates on the emission and roadside concentration of those regulated pollutants which are potentially harmful to the health or well-being of human, animal or plant life, or to ecological systems. However, vehicle emissions, especially those from diesel vehicles, may also cause a number of aesthetic and nuisance problems, such a visibility reduction, urban soiling and physical irritation. A methodology to investigated the subjective nuisance effects of air pollution from road traffic on the public has been developed and tested. The data indicates that vehicle-derived air pollution was an issue of high relative importance to the public when compared to other major social issues. On a local level, the physical presence of road traffic and its associated pollution appeared to be the largest contributors to outdoor public environmental nuisance. Indoors, the public appeared to experience only minor disturbances from vehicle-derived pollution, with the average respondent being not very bothered by vehicle-derived smoke, fumes and odour, dust and dirt and general air pollution. Noise appeared to cause the greatest indoor traffic-related nuisance, although many respondents complained about soiling from dust/dirt. The surveys suggest that outdoor disturbance from vehicle-derived air pollution was fairly high, with smoke, fumes and odour causing the greatest annoyance. The main reason given for disturbance from outdoor smoke, fumes and odour and dust/dirt was concern that they would harm the public's health. Other important specific reasons included soiling and the smell of the fumes.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Learning styles: The learning methods of air traffic control students

    NASA Astrophysics Data System (ADS)

    Jackson, Dontae L.

    In the world of aviation, air traffic controllers are an integral part in the overall level of safety that is provided. With a number of controllers reaching retirement age, the Air Traffic Collegiate Training Initiative (AT-CTI) was created to provide a stronger candidate pool. However, AT-CTI Instructors have found that a number of AT-CTI students are unable to memorize types of aircraft effectively. This study focused on the basic learning styles (auditory, visual, and kinesthetic) of students and created a teaching method to try to increase memorization in AT-CTI students. The participants were asked to take a questionnaire to determine their learning style. Upon knowing their learning styles, participants attended two classroom sessions. The participants were given a presentation in the first class, and divided into a control and experimental group for the second class. The control group was given the same presentation from the first classroom session while the experimental group had a group discussion and utilized Middle Tennessee State University's Air Traffic Control simulator to learn the aircraft types. Participants took a quiz and filled out a survey, which tested the new teaching method. An appropriate statistical analysis was applied to determine if there was a significant difference between the control and experimental groups. The results showed that even though the participants felt that the method increased their learning, there was no significant difference between the two groups.

  14. Cooperative interaction between leptin and amylin signaling in the ventral tegmental area for the control of food intake.

    PubMed

    Mietlicki-Baase, Elizabeth G; Olivos, Diana R; Jeffrey, Brianne A; Hayes, Matthew R

    2015-06-15

    Peripheral coadministration of amylin and leptin produces enhanced suppression of food intake and body weight, but the central nuclei mediating these effects remain unclear. Because each of these peptides controls feeding via actions at the ventral tegmental area (VTA), we tested the hypothesis that the VTA is a site of action for the cooperative effects of leptin and amylin on energy balance control. First, we show that intra-VTA injection of amylin and leptin at doses of each peptide that are effective in reducing food intake and body weight when administered separately produces an enhanced suppression of feeding when administered in combination. We also demonstrate that subthreshold doses of both amylin and leptin cause significant hypophagia and body weight loss when coadministered into the VTA. Additionally, we provide evidence that VTA amylin receptor blockade significantly attenuates the ability of intra-VTA leptin to reduce feeding and body weight gain. Together, these data provide the first evidence that the VTA mediates the interaction of amylin and leptin to cooperatively promote negative energy balance.

  15. Cooperative interaction between leptin and amylin signaling in the ventral tegmental area for the control of food intake

    PubMed Central

    Olivos, Diana R.; Jeffrey, Brianne A.; Hayes, Matthew R.

    2015-01-01

    Peripheral coadministration of amylin and leptin produces enhanced suppression of food intake and body weight, but the central nuclei mediating these effects remain unclear. Because each of these peptides controls feeding via actions at the ventral tegmental area (VTA), we tested the hypothesis that the VTA is a site of action for the cooperative effects of leptin and amylin on energy balance control. First, we show that intra-VTA injection of amylin and leptin at doses of each peptide that are effective in reducing food intake and body weight when administered separately produces an enhanced suppression of feeding when administered in combination. We also demonstrate that subthreshold doses of both amylin and leptin cause significant hypophagia and body weight loss when coadministered into the VTA. Additionally, we provide evidence that VTA amylin receptor blockade significantly attenuates the ability of intra-VTA leptin to reduce feeding and body weight gain. Together, these data provide the first evidence that the VTA mediates the interaction of amylin and leptin to cooperatively promote negative energy balance. PMID:25898952

  16. Simulation studies of time-control procedures for the advanced air traffic control system

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Alcabin, M.; Erzberger, H.; Obrien, P. J.

    1985-01-01

    The problem of mixing aircraft equipped with time-controlled guidance systems and unequipped aircraft in the terminal area has been investigated via a real-time air traffic control simulation. These four-dimensional (4D) guidance systems can predict and control the touchdown time of an aircraft to an accuracy of a few seconds throughout the descent. The objectives of this investigation were to (1) develop scheduling algorithms and operational procedures for various traffic mixes that ranged from 25% to 75% 4D-equipped aircraft; (2) examine the effect of time errors at 120 n. mi. from touchdown on touchdown time scheduling of the various mix conditions; and (3) develop efficient algorithms and procedures to null the initial time errors prior to reaching the final control sector, 30 n. mi. from touchdown. Results indicate substantial reduction in controller workload and an increase in orderliness when more than 25% of the aircraft are equipped with 4D guidance systems; initial random errors of up to + or - 2 min can be handled via a single speed advisory issued in the arrival control sector, thus avoiding disruption of the time schedule.

  17. Voice data entry in air traffic control

    NASA Technical Reports Server (NTRS)

    Connolly, Donald W.

    1977-01-01

    Several of the keyboard data languages were tabulated and analyzed. The key language chosen as a test vehicle was that used by the nonradar or flight data controllers. This application was undertaken to minimize effort in a cost efficient way and with less research and development.

  18. Proposal of Wireless Traffic Control Schemes for Wireless LANs

    NASA Astrophysics Data System (ADS)

    Hiraguri, Takefumi; Ichikawa, Takeo; Iizuka, Masataka; Kubota, Shuji

    This paper proposes two traffic control schemes to support the communication quality of multimedia streaming services such as VoIP and audio/video over IEEE 802.11 wireless LAN systems. The main features of the proposed scheme are bandwidth control for each flow of the multimedia streaming service and load balancing between access points (APs) of the wireless LAN by using information of data link, network and transport layers. The proposed schemes are implemented on a Linux machine which is called the wireless traffic controller (WTC). The WTC connects a high capacity backbone network and an access network to which the APs are attached. We evaluated the performance of the proposed WTC and confirmed that the communication quality of the multimedia streaming would be greatly improved by using this technique.

  19. Stabilization of traffic flow in optimal velocity model via delayed-feedback control

    NASA Astrophysics Data System (ADS)

    Jin, Yanfei; Hu, Haiyan

    2013-04-01

    Traffic jams may occur due to various reasons, such as traffic accidents, lane reductions and on-ramps. In order to suppress the traffic congestion in an optimal velocity traffic model without any driver's delay taken into account, a delayed-feedback control of both displacement and velocity differences is proposed in this study. By using the delay-independent stability criteria and the H∞-norm, the delayed-feedback control can be determined to stabilize the unstable traffic flow and suppress the traffic jam. The numerical case studies are given to demonstrate and verify the new control method. Furthermore, a comparison is made between the new control method and the method proposed by Konishi et al. [K. Konishi, M. Hirai, H. Kokame, Decentralized delayed-feedback control of an optimal velocity traffic model, Eur. Phys. J. B 15 (2000) 715-722]. The results show that the new control method makes the traffic flow more stable and improves the control performance.

  20. Visual and auditory reaction time for air traffic controllers using quantitative electroencephalograph (QEEG) data.

    PubMed

    Abbass, Hussein A; Tang, Jiangjun; Ellejmi, Mohamed; Kirby, Stephen

    2014-12-01

    The use of quantitative electroencephalograph in the analysis of air traffic controllers' performance can reveal with a high temporal resolution those mental responses associated with different task demands. To understand the relationship between visual and auditory correct responses, reaction time, and the corresponding brain areas and functions, air traffic controllers were given an integrated visual and auditory continuous reaction task. Strong correlations were found between correct responses to the visual target and the theta band in the frontal lobe, the total power in the medial of the parietal lobe and the theta-to-beta ratio in the left side of the occipital lobe. Incorrect visual responses triggered activations in additional bands including the alpha band in the medial of the frontal and parietal lobes, and the Sensorimotor Rhythm in the medial of the parietal lobe. Controllers' responses to visual cues were found to be more accurate but slower than their corresponding performance on auditory cues. These results suggest that controllers are more susceptible to overload when more visual cues are used in the air traffic control system, and more errors are pruned as more auditory cues are used. Therefore, workload studies should be carried out to assess the usefulness of additional cues and their interactions with the air traffic control environment.

  1. Fuel efficient traffic signal operation and evaluation: Garden Grove Demonstration Project

    SciTech Connect

    Not Available

    1983-02-01

    The procedures and results of a case study of fuel efficient traffic signal operation and evaluation in the City of Garden Grove, California are documented. Improved traffic signal timing was developed for a 70-intersection test network in Garden Grove using an optimization tool called the TRANSYT Version 8 computer program. Full-scale field testing of five alternative timing plans was conducted using two instrumented vehicles equipped to measure traffic performance characteristics and fuel consumption. The field tests indicated that significant improvements in traffic flow and fuel consumption result from the use of timing plans generated by the TRANSYT optimization model. Changing from pre-existing to an optimized timing plan yields a networkwide 5 percent reduction in total travel time, more than 10 percent reduction in both the number of stops and stopped delay time, and 6 percent reduction in fuel consumption. Projections are made of the benefits and costs of implementing such a program at the 20,000 traffic signals in networks throughout the State of California.

  2. Controlling traffic jams by time modulating the safety distance

    NASA Astrophysics Data System (ADS)

    Gaididei, Yu. B.; Gorria, C.; Berkemer, R.; Kawamoto, A.; Shiga, T.; Christiansen, P. L.; Sørensen, M. P.; Starke, J.

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  3. Controlling traffic jams by time modulating the safety distance.

    PubMed

    Gaididei, Yu B; Gorria, C; Berkemer, R; Kawamoto, A; Shiga, T; Christiansen, P L; Sørensen, M P; Starke, J

    2013-10-01

    The possibility of controlling traffic dynamics by applying high-frequency time modulation of traffic flow parameters is studied. It is shown that the region of the car density where the uniform (free) flow is unstable changes in the presence of time modulation compared with the unmodulated case. This region shrinks when the speed-up of cars does not exceed some critical value and expands in the opposite case. The flux of the time-modulated flow is an increasing function of the amplitude of the modulation for traffic flows whose density is larger than 1/h where h is the safety distance in the nonmodulated case, while it is a decreasing function in the opposite case. In other words, the safety distance time modulation facilitates car propagation in the case when the mean distance between cars in the congestive traffic is less than h and hinders it when the neighboring cars in the flow are well separated. A link between a microscopic description and the macroscopic fundamental diagram is established.

  4. Traffic control: regulation of kinesin motors.

    PubMed

    Verhey, Kristen J; Hammond, Jennetta W

    2009-11-01

    Kinesins are a family of molecular motors that use the energy of ATP hydrolysis to move along the surface of, or destabilize, microtubule filaments. Much progress has been made in understanding the mechanics and functions of the kinesin motors that play important parts in cell division, cell motility, intracellular trafficking and ciliary function. How kinesins are regulated in cells to ensure the temporal and spatial fidelity of their microtubule-based activities is less well understood. Recent work has revealed molecular mechanisms that control kinesin autoinhibition and subsequent activation, binding to cargos and microtubule tracks, and localization at specific sites of action.

  5. 23 CFR 630.1110 - Maintenance of temporary traffic control devices.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... traffic control devices, each agency shall develop and implement quality guidelines to help maintain the quality and adequacy of the temporary traffic control devices for the duration of the project. Agencies... Association's (ATSSA) Quality Guidelines for Work Zone Traffic Control Devices uses photos and...

  6. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... traffic control systems. 236.476 Section 236.476 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control systems. The inspections and tests prescribed in §§...

  7. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... traffic control systems. 236.476 Section 236.476 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control systems. The inspections and tests prescribed in §§...

  8. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... traffic control systems. 236.426 Section 236.426 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control systems. The rules and instructions prescribed...

  9. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... traffic control systems. 236.426 Section 236.426 Transportation Other Regulations Relating to... SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control systems. The rules and instructions prescribed...

  10. 5 CFR 842.405 - Air traffic controllers, firefighters, law enforcement officers, and nuclear materials couriers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Air traffic controllers, firefighters... RETIREMENT SYSTEM-BASIC ANNUITY Computations § 842.405 Air traffic controllers, firefighters, law enforcement officers, and nuclear materials couriers. The annuity of an air traffic controller retiring under § 842.207...

  11. 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.

  12. Automated Air Traffic Control Operations with Weather and Time-Constraints: A First Look at (Simulated) Far-Term Control Room Operations

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas; Homola, Jeffrey R.; Martin, Lynne H.; Mercer, Joey S.; Cabrall, Christopher C.

    2011-01-01

    In this paper we discuss results from a recent high fidelity simulation of air traffic control operations with automated separation assurance in the presence of weather and time-constraints. We report findings from a human-in-the-loop study conducted in the Airspace Operations Laboratory (AOL) at the NASA Ames Research Center. During four afternoons in early 2010, fifteen active and recently retired air traffic controllers and supervisors controlled high levels of traffic in a highly automated environment during three-hour long scenarios, For each scenario, twelve air traffic controllers operated eight sector positions in two air traffic control areas and were supervised by three front line managers, Controllers worked one-hour shifts, were relieved by other controllers, took a 3D-minute break, and worked another one-hour shift. On average, twice today's traffic density was simulated with more than 2200 aircraft per traffic scenario. The scenarios were designed to create peaks and valleys in traffic density, growing and decaying convective weather areas, and expose controllers to heavy and light metering conditions. This design enabled an initial look at a broad spectrum of workload, challenge, boredom, and fatigue in an otherwise uncharted territory of future operations. In this paper we report human/system integration aspects, safety and efficiency results as well as airspace throughput, workload, and operational acceptability. We conclude that, with further refinements. air traffic control operations with ground-based automated separation assurance can be an effective and acceptable means to routinely provide very high traffic throughput in the en route airspace.

  13. Free flight: air traffic control evolution or revolution

    NASA Astrophysics Data System (ADS)

    Grundmann, Karl

    1996-05-01

    The Federal Aviation Administration (FAA) and industry are moving towards a more flexible, user oriented air traffic control system. The question is: does this point to a natural evolution or revolution in the world of the air traffic controllers? The National Airspace System is by all accounts the safest in the world. How will we sustain this record of performance with increased flexibility and user involvement? How will controllers and pilots react to a new more dynamic paradigm? Is the current state of automation, modeling, and analysis what is needed to make Free Flight a reality? How will the FAA insure that all human factors questions are answered before implementation? How will we quantify the impact of unanswered questions and their influence on safety? These, and many more questions need to be answered to ensure that the benefits promised by Free Flight are realized by all parties. The National Air Traffic Controllers Association supports the new concept. Yet, we are seriously concerned about the actual implementation of Free Flight's various components.

  14. Human resources for the control of road traffic injury.

    PubMed

    Mock, Charles; Kobusingye, Olive; Anh, Le Vu; Afukaar, Francis; Arreola-Risa, Carlos

    2005-04-01

    The definition of the ideal numbers and distribution of human resources required for control of road traffic injury (RTI) is not as advanced as for other health problems. We can nonetheless identify functions that need to be addressed across the spectrum of injury control: surveillance; road safety (including infrastructure, vehicle design, and behaviour); and trauma care. Many low-cost strategies to improve these functions in low- or middle-income countries can be identified. For all these strategies, there is need for adequate institutional capacity, including funding, legal authority, and human resources. Several categories of human resources need to be developed: epidemiologists who can handle injury data, design surveillance systems, and undertake research; engineers and planners versed in safety aspects of road design, traffic flow, urban planning, and vehicle design; police and lawyers who understand the health impact of traffic law; clinicians who can develop cost-effective improvements in the entire system of trauma treatment; media experts to undertake effective behaviour change and social marketing; and economists to assist with cost-effectiveness evaluations. RTI control can be strengthened by enhancing such training in these disciplines, as well as encouraging retention of those who have the needed skills. Mechanisms to enhance collaboration between these different fields need to be promoted. Finally, the burden of RTI is borne disproportionately by the poor; in addition to technical issues, more profound equity issues must be addressed. This mandates that people from all professional backgrounds who work for RTI control should develop skills in advocacy and politics.

  15. Reasons underlying behaviour of motorcyclists disregarding traffic regulations in urban areas of Indonesia.

    PubMed

    Susilo, Yusak O; Joewono, Tri Basuki; Vandebona, Upali

    2015-02-01

    Over the last decade, motorcycle use has been rapidly increasing in Indonesia as have violations of traffic rules committed by motorcyclists. This study aims to explore the impacts of motorcyclists' attitudes, habits, preferences, and travel patterns on their behaviour in disregarding traffic regulations in three cities in Indonesia. The theory of planned behaviour and structural equation modelling are employed to explore these relationships. Consistent with results from previous studies in developed countries, an individual's beliefs and attitudes, social norms and perceived behaviour control significantly influence behaviour in disregarding traffic rules. Young adults and students are found to be more likely to frequently violate traffic regulations. However, unlike previous findings from developed countries, in Indonesia, males are less likely to disregard traffic rules than females. Overall, pushing the motorcycle through a (very) narrow gap, speeding, driving recklessly, and overtaking on the wrong side are the most frequent traffic violations that make up repetitive violation behaviour among urban motorcyclists in Indonesia. The results highlight the need to revisit Indonesian National Traffic Law traffic violation classification and penalties and separate violations that are likely to cause fatal results, thus requiring tougher law enforcement, from violations that are unlikely to have fatal consequences. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. A novel solution for car traffic control based on radiometric microwave devices

    NASA Astrophysics Data System (ADS)

    Soldovieri, Francesco; Denisov, Alexander; Speziale, Victor

    2014-05-01

    The significant problem of traffic in big cities, connected with huge and building up quantity of automobile cars, demands for novel strategies, based on nonconventional solutions, in order to improve system traffic control, especially at crossroads. As well known, the usual solution is based on the time relay, which requires the installation of a fixed traffic interval (signal light switching) at a crossroad; this solution is low cost, but does not account for the actual traffic conditions. Therefore, in the recent years, attention is towards to new designs, where the monitoring of the and control of traffic is carried out by using various methods including, optical, the infrared, magnetic, radar tracking, acoustical ones. In this work, we discuss the deployment of high sensitivity radiometric systems and radiometers(sensor) in the microwave range [1, 2]. In fact, the radiometer as "sensor" can provide an always updated information about the car traffic in any weather condition and in absence or low visibility conditions. In fact, the radiometric sensor detects the cars thanks to the different behavior of the car roofs which reflect the cold sky whereas the road asphalt is visible as warm object (at around outside temperature). [1] A. G. Denisov, V. P. Gorishnyak, S. E. Kuzmin et al., "Some experiments concerning resolution of 32 sensors passive 8mm wave imaging system," in Proceedings of the International Symposium on Space Terahertz Technology (ISSTT '09), Charlottesville, Va, USA, April 2009. [2] F. Soldovieri, A. Natale, V. Gorishnyak, A. Pavluchenko, A. Denisov, and L. Chen, "Radiometric Imaging for Monitoring and Surveillance Issues," International Journal of Antennas and Propagation, vol. 2013, Article ID 272561, 8 pages, 2013. doi:10.1155/2013/272561.

  17. Area-wide urban traffic calming schemes: a meta-analysis of safety effects.

    PubMed

    Elvik, R

    2001-05-01

    This paper presents a meta-analysis of 33 studies that have evaluated the effects on road safety of area-wide urban traffic calming schemes. Area-wide urban traffic calming schemes are typically implemented in residential areas in towns in order to reduce the environmental and safety problems caused by road traffic. A hierarchical road system is established and through traffic is removed from residential streets by means of, for example, street closures or one-way systems. Speed reducing devices are often installed in residential streets. Main roads are improved in order to carry a larger traffic volume without additional delays or more accidents. The meta-analysis shows that area-wide urban traffic calming schemes on the average reduce the number of injury accidents by about 15%. The largest reduction in the number of accidents is found for residential streets (about 25%), a somewhat smaller reduction is found for main roads (about 10%). Similar reductions are found in the number of property damage only accidents. The results of evaluation studies are robust with respect to study design. There is no evidence of publication bias in evaluation studies. Study findings are found to have high external validity.

  18. Simulation of time-control procedures for the advanced air traffic control system

    NASA Technical Reports Server (NTRS)

    Tobias, L.; Obrien, P. J.

    1984-01-01

    The problem of mixing four-dimensional (4D) equipped aircraft - aircraft equipped with on-board guidance systems that can predict and control the touchdown time of an aircraft to an accuracy of a few seconds throughout the descent - with unequipped aircraft in the terminal area has been investigated via a real-time air traffic control simulation study. The objective of this study was to examine the effect of time errors (at 120 n. mi. from touchdown) on touchdown time scheduling, and to develop efficient algorithms and procedures to null the initial time errors prior to reaching the final control sector (30 n. mi. from touchdown). Results indicate that initial random errors of up to + or - 2 min can be handled via a single speed advisory issued in the arrival control sector, and thus the time schedule is not disrupted.

  19. How to reduce workload--augmented reality to ease the work of air traffic controllers.

    PubMed

    Hofmann, Thomas; König, Christina; Bruder, Ralph; Bergner, Jörg

    2012-01-01

    In the future the air traffic will rise--the workload of the controllers will do the same. In the BMWi research project, one of the tasks is, how to ensure safe air traffic, and a reasonable workload for the air traffic controllers. In this project it was the goal to find ways how to reduce the workload (and stress) for the controllers to allow safe air traffic, esp. at huge hub-airports by implementing augmented reality visualization and interaction.

  20. 14 CFR 93.177 - Operations in the Special Air Traffic Rule Area.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Luke Terminal Area designated in § 93.176 unless— (1) Before operating within the Luke Terminal area... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operations in the Special Air Traffic Rule Area. 93.177 Section 93.177 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF...

  1. Classification of Traffic Related Short Texts to Analyse Road Problems in Urban Areas

    NASA Astrophysics Data System (ADS)

    Saldana-Perez, A. M. M.; Moreno-Ibarra, M.; Tores-Ruiz, M.

    2017-09-01

    The Volunteer Geographic Information (VGI) can be used to understand the urban dynamics. In the classification of traffic related short texts to analyze road problems in urban areas, a VGI data analysis is done over a social media's publications, in order to classify traffic events at big cities that modify the movement of vehicles and people through the roads, such as car accidents, traffic and closures. The classification of traffic events described in short texts is done by applying a supervised machine learning algorithm. In the approach users are considered as sensors which describe their surroundings and provide their geographic position at the social network. The posts are treated by a text mining process and classified into five groups. Finally, the classified events are grouped in a data corpus and geo-visualized in the study area, to detect the places with more vehicular problems.

  2. Operational air traffic control requirements for the new Voice Switching and Control System

    NASA Technical Reports Server (NTRS)

    Leon, N.

    1984-01-01

    Final user requirements defined for the Voice Switching and Control System (VSCS) to be implemented for ATC functions as part of the Area Control Facility (ACF) concept for the National Airspace System (NAS) are described. The VSCS will be communications equipment at operational stations, supervisory positions, and support systems, the switching system itself, and interfaces between the VSCS and other systems. Supervisory users will include the Area Manager, Traffic Management Coordinator, a Military Operations Specialists, a Weather Coordinator, a NAS manager, Maintenance, and a flight Data Communications Specialist. The VSCS will supply computerized communications capability within and among ATC centers. Details of the efforts used to define the system requirements are recounted, noting the heavy reliance on recommendations from active ATC personnel.

  3. Operational air traffic control requirements for the new Voice Switching and Control System

    NASA Technical Reports Server (NTRS)

    Leon, N.

    1984-01-01

    Final user requirements defined for the Voice Switching and Control System (VSCS) to be implemented for ATC functions as part of the Area Control Facility (ACF) concept for the National Airspace System (NAS) are described. The VSCS will be communications equipment at operational stations, supervisory positions, and support systems, the switching system itself, and interfaces between the VSCS and other systems. Supervisory users will include the Area Manager, Traffic Management Coordinator, a Military Operations Specialists, a Weather Coordinator, a NAS manager, Maintenance, and a flight Data Communications Specialist. The VSCS will supply computerized communications capability within and among ATC centers. Details of the efforts used to define the system requirements are recounted, noting the heavy reliance on recommendations from active ATC personnel.

  4. Cellular Automaton Models of Highway Traffic Flow Considering Lane-Control and Speed-Control

    NASA Astrophysics Data System (ADS)

    Qian, Yong-Sheng; Li, Wen-Jun; Zeng, Jun-Wei; Wang, Min; Du, Jia-Wei; Guang, Xiao-Ping

    2011-10-01

    As two kinds of management modes of highway traffic control, lane-control, and speed-control produce different effect under different conditions. In this paper, traffic flow cellular automaton models for four-lane highway system with two opposing directions under the above two modes are established considering car and truck mixed running. Through computer numerical simulating, the fundamental diagrams with different parameters are obtained, and after the analysis of density-flux diagrams, the variation discipline of flux with traffic density under different control models is gained. The results indicate that, compared with lane-control, utilization ratio of road can be further improved with speed-control when the truck number increases. The research result is of great significance for reasonable providing theoretical guidance for highway traffic control.

  5. 10 CFR 429.49 - Traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.49 Traffic signal... nominal wattage or other measure of energy consumption of a basic model for which consumers would favor...: ER02MY11.082 and (ii) Any represented value of the energy efficiency or other measure of energy...

  6. 10 CFR 429.49 - Traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.49 Traffic signal... nominal wattage or other measure of energy consumption of a basic model for which consumers would favor...: ER02MY11.082 and (ii) Any represented value of the energy efficiency or other measure of energy...

  7. 10 CFR 429.49 - Traffic signal modules and pedestrian modules.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... FOR CONSUMER PRODUCTS AND COMMERCIAL AND INDUSTRIAL EQUIPMENT Certification § 429.49 Traffic signal... nominal wattage or other measure of energy consumption of a basic model for which consumers would favor...: ER02MY11.082 and (ii) Any represented value of the energy efficiency or other measure of energy...

  8. 10 CFR 431.224 - Uniform test method for the measurement of energy consumption for traffic signal modules and...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform test method for the measurement of energy consumption for traffic signal modules and pedestrian modules. 431.224 Section 431.224 Energy DEPARTMENT OF... measurement of energy consumption for traffic signal modules and pedestrian modules. (a) Scope. This section...

  9. 49 CFR 236.405 - Track signaled for movements in both directions, change of direction of traffic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Track signaled for movements in both directions, change of direction of traffic. 236.405 Section 236.405 Transportation Other Regulations Relating to... in both directions, change of direction of traffic. On track signaled for movements in both...

  10. Evaluating the Effects of Traffic on Driver Stopping and Turn Signal Use at a Stop Sign: A Systematic Replication

    ERIC Educational Resources Information Center

    Lebbon, Angela R.; Austin, John; Van Houten, Ron; Malenfant, Louis E.

    2007-01-01

    The current analyses of observational data found that oncoming traffic substantially affected driver stopping patterns and turn signal use at the target stop sign. The percentage of legal stops and turn signal use by drivers in the presence and absence of traffic was analyzed using a multi-element design. The results showed that legal stops were…

  11. Evaluating the Effects of Traffic on Driver Stopping and Turn Signal Use at a Stop Sign: A Systematic Replication

    ERIC Educational Resources Information Center

    Lebbon, Angela R.; Austin, John; Van Houten, Ron; Malenfant, Louis E.

    2007-01-01

    The current analyses of observational data found that oncoming traffic substantially affected driver stopping patterns and turn signal use at the target stop sign. The percentage of legal stops and turn signal use by drivers in the presence and absence of traffic was analyzed using a multi-element design. The results showed that legal stops were…

  12. 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.

  13. A Vision of the Future Air Traffic Control System

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2000-01-01

    The air transportation system is on the verge of gridlock, with delays and cancelled flights this summer reaching all time highs. As demand for air transportation continues to increase, the capacity needed to accommodate the growth in traffic is falling farther and farther behind. Moreover, it has become increasingly apparent that the present system cannot be scaled up to provide the capacity increases needed to meet demand over the next 25 years. NASA, working with the Federal Aviation Administration and industry, is pursuing a major research program to develop air traffic management technologies that have the ultimate goal of doubling capacity while increasing safety and efficiency. This seminar will describe how the current system operates, what its limitations are and why a revolutionary "shift in paradigm" is needed to overcome fundamental limitations in capacity and safety. For the near term, NASA has developed a portfolio of software tools for air traffic controllers, called the Center-TRACON Automation System (CTAS), that provides modest gains in capacity and efficiency while staying within the current paradigm. The outline of a concept for the long term, with a deployment date of 2015 at the earliest, has recently been formulated and presented by NASA to a select group of industry and government stakeholders. Automated decision making software, combined with an Internet in the sky that enables sharing of information and distributes control between the cockpit and the ground, is key to this concept. However, its most revolutionary feature is a fundamental change in the roles and responsibilities assigned to air traffic controllers.

  14. A Vision of the Future Air Traffic Control System

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz

    2000-01-01

    The air transportation system is on the verge of gridlock, with delays and cancelled flights this summer reaching all time highs. As demand for air transportation continues to increase, the capacity needed to accommodate the growth in traffic is falling farther and farther behind. Moreover, it has become increasingly apparent that the present system cannot be scaled up to provide the capacity increases needed to meet demand over the next 25 years. NASA, working with the Federal Aviation Administration and industry, is pursuing a major research program to develop air traffic management technologies that have the ultimate goal of doubling capacity while increasing safety and efficiency. This seminar will describe how the current system operates, what its limitations are and why a revolutionary "shift in paradigm" is needed to overcome fundamental limitations in capacity and safety. For the near term, NASA has developed a portfolio of software tools for air traffic controllers, called the Center-TRACON Automation System (CTAS), that provides modest gains in capacity and efficiency while staying within the current paradigm. The outline of a concept for the long term, with a deployment date of 2015 at the earliest, has recently been formulated and presented by NASA to a select group of industry and government stakeholders. Automated decision making software, combined with an Internet in the sky that enables sharing of information and distributes control between the cockpit and the ground, is key to this concept. However, its most revolutionary feature is a fundamental change in the roles and responsibilities assigned to air traffic controllers.

  15. The Crossroads of Synaptic Growth Signaling, Membrane Traffic and Neurological Disease: Insights from Drosophila.

    PubMed

    Deshpande, Mugdha; Rodal, Avital A

    2016-02-01

    Neurons require target-derived autocrine and paracrine growth factors to maintain proper identity, innervation, homeostasis and survival. Neuronal growth factor signaling is highly dependent on membrane traffic, both for the packaging and release of the growth factors themselves, and for regulation of intracellular signaling by their transmembrane receptors. Here, we review recent findings from the Drosophila larval neuromuscular junction (NMJ) that illustrate how specific steps of intracellular traffic and inter-organelle interactions impinge on signaling, particularly in the bone morphogenic protein, Wingless and c-Jun-activated kinase pathways, regulating elaboration and stability of NMJ arbors, construction of synapses and synaptic transmission and homeostasis. These membrane trafficking and signaling pathways have been implicated in human motor neuron diseases including amyotrophic lateral sclerosis and hereditary spastic paraplegia, highlighting their importance for neuronal health and survival.

  16. Traffic noise and hypertension - results from a large case-control study.

    PubMed

    Zeeb, Hajo; Hegewald, Janice; Schubert, Melanie; Wagner, Mandy; Dröge, Patrik; Swart, Enno; Seidler, Andreas

    2017-08-01

    Environmental traffic noise is a potential cause of hypertension. We aimed to study the association between hypertension as recorded in health insurance claims data and the exposure to three sources of traffic noise (aircraft, road and rail). This large case-control study was conducted among persons aged 40 and above in 2010 and living in the region around Frankfurt airport in Germany. Individual residential noise exposure for the index year 2005 was assessed using standard noise algorithms. Cases were all newly diagnosed cases of hypertension recorded in three large health insurances databases in the period 2006-2010. Controls had no hypertension diagnosis. Categorical and continuous analyses were conducted with binary logistic regression models adjusted for sex, age and residential area-based socioeconomic information. The main analysis included 137,577 cases and 355,591 controls. There were no associations with any of the traffic noise sources. Odds ratios (OR) per 10dB noise increase were 0.99 (95% confidence interval: 0.98;1.01) for aircraft noise, and 1.00 (0.99;1.01) both for road and railway noise. Similarly, nighttime noise levels showed no associations with hypertension. Odds ratios were increased for the subgroup of newly diagnosed hypertension cases with a subsequent diagnosis of hypertensive heart disease: per 10dB aircraft noise there was a 13.9% OR increase (6.0% for road traffic, 5.4% for rail traffic). Increases were also noted when we analyzed cases with a longer exposure-outcome time window. Our results are suggestive of an association of noise exposure with clinically more severe hypertension diagnoses, but not with uncomplicated hypertension. The absence of individual confounder data, however, adds to the risk of bias. The results contribute to evidence on traffic noise as a cardiovascular risk factor. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. 32 CFR 636.21 - Obedience to official traffic control devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Obedience to official traffic control devices... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.21 Obedience to official traffic control devices. (a) All...

  18. 32 CFR 636.21 - Obedience to official traffic control devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Obedience to official traffic control devices... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.21 Obedience to official traffic control devices. (a) All...

  19. 32 CFR 636.21 - Obedience to official traffic control devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Obedience to official traffic control devices... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.21 Obedience to official traffic control devices. (a) All...

  20. 32 CFR 636.21 - Obedience to official traffic control devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Obedience to official traffic control devices... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.21 Obedience to official traffic control devices. (a) All...

  1. 32 CFR 636.21 - Obedience to official traffic control devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Obedience to official traffic control devices... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.21 Obedience to official traffic control devices. (a) All...

  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. 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.

  4. 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.

  5. 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.

  6. CSMA Versus Prioritized CSMA for Air-Traffic-Control Improvement

    NASA Technical Reports Server (NTRS)

    Robinson, Daryl C.

    2001-01-01

    OPNET version 7.0 simulations are presented involving an important application of the Aeronautical Telecommunications Network (ATN), Controller Pilot Data Link Communications (CPDLC) over the Very High Frequency Data Link, Mode 2 (VDL-2). Communication is modeled for essentially all incoming and outgoing nonstop air-traffic for just three United States cities: Cleveland, Cincinnati, and Detroit. There are 32 airports in the simulation, 29 of which are either sources or destinations for the air-traffic of the aforementioned three airports. The simulation involves 111 Air Traffic Control (ATC) ground stations, and 1,235 equally equipped aircraft-taking off, flying realistic free-flight trajectories, and landing in a 24-hr period. Collisionless, Prioritized Carrier Sense Multiple Access (CSMA) is successfully tested and compared with the traditional CSMA typically associated with VDL-2. The performance measures include latency, throughput, and packet loss. As expected, Prioritized CSMA is much quicker and more efficient than traditional CSMA. These simulation results show the potency of Prioritized CSMA for implementing low latency, high throughput, and efficient connectivity.

  7. Chain-reaction crash in traffic flow controlled by taillights

    NASA Astrophysics Data System (ADS)

    Nagatani, Takashi

    2015-02-01

    We study the chain-reaction crash (multiple-vehicle collision) in low-visibility condition on a road. In the traffic situation, drivers brake according to taillights of the forward vehicle. The first crash may induce more collisions. We investigate whether or not the first collision induces the chain-reaction crash, numerically and analytically. The dynamic transitions occur from no collisions through a single collision, double collisions and triple collisions, to multiple collisions with decreasing the headway. Also, we find that the dynamic transition occurs from the finite chain reaction to the infinite chain reaction when the headway is less than the critical value. We derive, analytically, the transition points and the region maps for the chain-reaction crash in traffic flow controlled by taillights.

  8. Automation of Data Traffic Control on DSM Architecture

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Jin, Hao-Qiang; Yan, Jerry

    2001-01-01

    The design of distributed shared memory (DSM) computers liberates users from the duty to distribute data across processors and allows for the incremental development of parallel programs using, for example, OpenMP or Java threads. DSM architecture greatly simplifies the development of parallel programs having good performance on a few processors. However, to achieve a good program scalability on DSM computers requires that the user understand data flow in the application and use various techniques to avoid data traffic congestions. In this paper we discuss a number of such techniques, including data blocking, data placement, data transposition and page size control and evaluate their efficiency on the NAS (NASA Advanced Supercomputing) Parallel Benchmarks. We also present a tool which automates the detection of constructs causing data congestions in Fortran array oriented codes and advises the user on code transformations for improving data traffic in the application.

  9. [Hospital information system performance for road traffic accidents analysis in a hospital recruitment based area].

    PubMed

    Jannot, A-S; Fauconnier, J

    2013-06-01

    Road traffic accidents in France are mainly analyzed through reports completed by the security forces (police and gendarmerie). But the hospital information systems can also identify road traffic accidents via specific documentary codes of the International Classification of Diseases (ICD-10). The aim of this study was therefore to determine whether hospital stays consecutive to road traffic accident were truly identified by these documentary codes in a facility that collects data routinely and to study the consistency of results from hospital information systems and from security forces during the 2002-2008 period. We retrieved all patients for whom a documentary code for road traffic accident was entered in 2002-2008. We manually checked the concordance of documentary code for road traffic accident and trauma origin in 350 patient files. The number of accidents in the Grenoble area was then inferred by combining with hospitalization regional data and compared to the number of persons injured by traffic accidents declared by the security force. These hospital information systems successfully report road traffic accidents with 96% sensitivity (95%CI: [92%, 100%]) and 97% specificity (95%CI: [95%, 99%]). The decrease in road traffic accidents observed was significantly less than that observed was significantly lower than that observed in the data from the security force (45% for security force data against 27% for hospital data). Overall, this study shows that hospital information systems are a powerful tool for studying road traffic accidents morbidity in hospital and are complementary to security force data. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  10. Air traffic control surveillance accuracy and update rate study

    NASA Technical Reports Server (NTRS)

    Craigie, J. H.; Morrison, D. D.; Zipper, I.

    1973-01-01

    The results of an air traffic control surveillance accuracy and update rate study are presented. The objective of the study was to establish quantitative relationships between the surveillance accuracies, update rates, and the communication load associated with the tactical control of aircraft for conflict resolution. The relationships are established for typical types of aircraft, phases of flight, and types of airspace. Specific cases are analyzed to determine the surveillance accuracies and update rates required to prevent two aircraft from approaching each other too closely.

  11. Air traffic control using a microwave landing system

    NASA Technical Reports Server (NTRS)

    Gershzohn, G.

    1980-01-01

    The performance of air traffic controllers using a simulated microwave landing system to control the landing of STOL aircraft is investigated. In a series of two experiments, controllers were asked to achieve a 60-sec separation between targets at the missed approach point when only two targets were on the simulated radar scope, and in the presence of 25 targets, with up to 10 on the screen at any one time. In both experiments, the presence of a ground wind is found to degrade separation performance, and an increased work load results in even greater separation variability, as the controllers did not have time to convert aircraft distances into times. In addition, curved courses are found to have an effect on performance. It is thus recommended that in order to create a practical air traffic control system with separation standards based on time, as in the MLS, controller work loads should be reduced and aircraft positions should be displayed with respect to time rather than distance.

  12. Effect of adaptive cruise control systems on traffic flow

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2004-06-01

    The flow of traffic composed of vehicles that are equipped with adaptive cruise control (ACC) is studied using simulations. The ACC vehicles are modeled by a linear dynamical equation that has string stability. In platoons of all ACC vehicles, perturbations due to changes in the lead vehicle’s velocity do not cause jams. Simulations of merging flows near an onramp show that if the total incoming rate does not exceed the capacity of the single outgoing lane, free flow is maintained. With larger incoming flows, a state closely related to the synchronized flow phase found in manually driven vehicular traffic has been observed. This state, however, should not be considered congested because the flow is maximal for the density. Traffic composed of random sequences of ACC vehicles and manual vehicles has also been studied. At high speeds ( ˜30 m/s ) jamming occurs for concentrations of ACC vehicles of 10% or less. At 20% no jams are formed. The formation of jams is sensitive to the sequence of vehicles (ACC or manual). At lower speeds ( ˜15 m/s ) , no critical concentration for complete jam suppression is found. Rather, the average velocity in the pseudojam region increases with increasing ACC concentration. Mixing 50% ACC vehicles randomly with manually driven vehicles on the primary lane in onramp simulations shows only modestly reduced travel times and larger flow rates.

  13. Effect of adaptive cruise control systems on traffic flow.

    PubMed

    Davis, L C

    2004-06-01

    The flow of traffic composed of vehicles that are equipped with adaptive cruise control (ACC) is studied using simulations. The ACC vehicles are modeled by a linear dynamical equation that has string stability. In platoons of all ACC vehicles, perturbations due to changes in the lead vehicle's velocity do not cause jams. Simulations of merging flows near an onramp show that if the total incoming rate does not exceed the capacity of the single outgoing lane, free flow is maintained. With larger incoming flows, a state closely related to the synchronized flow phase found in manually driven vehicular traffic has been observed. This state, however, should not be considered congested because the flow is maximal for the density. Traffic composed of random sequences of ACC vehicles and manual vehicles has also been studied. At high speeds (approximately 30 m/s ) jamming occurs for concentrations of ACC vehicles of 10% or less. At 20% no jams are formed. The formation of jams is sensitive to the sequence of vehicles (ACC or manual). At lower speeds (approximately 15 m/s ), no critical concentration for complete jam suppression is found. Rather, the average velocity in the pseudojam region increases with increasing ACC concentration. Mixing 50% ACC vehicles randomly with manually driven vehicles on the primary lane in onramp simulations shows only modestly reduced travel times and larger flow rates.

  14. Traffic signal design and simulation for vulnerable road users safety and bus preemption

    NASA Astrophysics Data System (ADS)

    Lo, Shih-Ching; Huang, Hsieh-Chu

    2015-01-01

    Mostly, pedestrian car accidents occurred at a signalized interaction is because pedestrians cannot across the intersection safely within the green light. From the viewpoint of pedestrian, there might have two reasons. The first one is pedestrians cannot speed up to across the intersection, such as the elders. The other reason is pedestrians do not sense that the signal phase is going to change and their right-of-way is going to be lost. Developing signal logic to protect pedestrian, who is crossing an intersection is the first purpose of this study. In addition, to improve the reliability and reduce delay of public transportation service is the second purpose. Therefore, bus preemption is also considered in the designed signal logic. In this study, the traffic data of the intersection of Chong-Qing North Road and Min-Zu West Road, Taipei, Taiwan, is employed to calibrate and validate the signal logic by simulation. VISSIM 5.20, which is a microscopic traffic simulation software, is employed to simulate the signal logic. From the simulated results, the signal logic presented in this study can protect pedestrians crossing the intersection successfully. The design of bus preemption can reduce the average delay. However, the pedestrian safety and bus preemption signal will influence the average delay of cars largely. Thus, whether applying the pedestrian safety and bus preemption signal logic to an intersection or not should be evaluated carefully.

  15. Traffic signal design and simulation for vulnerable road users safety and bus preemption

    SciTech Connect

    Lo, Shih-Ching; Huang, Hsieh-Chu

    2015-01-22

    Mostly, pedestrian car accidents occurred at a signalized interaction is because pedestrians cannot across the intersection safely within the green light. From the viewpoint of pedestrian, there might have two reasons. The first one is pedestrians cannot speed up to across the intersection, such as the elders. The other reason is pedestrians do not sense that the signal phase is going to change and their right-of-way is going to be lost. Developing signal logic to protect pedestrian, who is crossing an intersection is the first purpose of this study. In addition, to improve the reliability and reduce delay of public transportation service is the second purpose. Therefore, bus preemption is also considered in the designed signal logic. In this study, the traffic data of the intersection of Chong-Qing North Road and Min-Zu West Road, Taipei, Taiwan, is employed to calibrate and validate the signal logic by simulation. VISSIM 5.20, which is a microscopic traffic simulation software, is employed to simulate the signal logic. From the simulated results, the signal logic presented in this study can protect pedestrians crossing the intersection successfully. The design of bus preemption can reduce the average delay. However, the pedestrian safety and bus preemption signal will influence the average delay of cars largely. Thus, whether applying the pedestrian safety and bus preemption signal logic to an intersection or not should be evaluated carefully.

  16. Commercial machine vision system for traffic monitoring and control

    NASA Astrophysics Data System (ADS)

    D Agostino, Salvatore A.

    1992-03-01

    Traffic imaging covers a range of current and potential applications. These include traffic control and analysis, license plate finding, reading and storage, violation detection and archiving, vehicle sensors, and toll collection/enforcement. Experience from commercial installations and knowledge of the system requirements have been gained over the past 10 years. Recent improvements in system component cost and performance now allow products to be applied that provide cost effective solutions to the requirements for truly intelligent vehicle/highway systems (IVHS). The United States is a country that loves to drive. The infrastructure built in the 1950s and 1960s along with the low price of gasoline created an environment where the automobiles became an accessible and intricate part of American life. The United States has spent $DLR103 billion to build 40,000 highway miles since 1956, the start of the interstate program which is nearly complete. Unfortunately, a situation has arisen where the options for dramatically improving the ability of our roadways to absorb the increasing amount of traffic is limited. This is true in other countries as well as in the United States. The number of vehicles in the world increases by over 10,000,000 each year. In the United States there are about 180 million cars, trucks, and buses and this is estimated to double in the next 30 years. Urban development, and development in general, pushes from the edge of our roadways out. This leaves little room to increase the physical amount of roadway. Americans now spend more than 1.6 billion hours a year waiting in traffic jams. It is estimated that this congestion wasted 3 billion gallons of oil or 4% of the nation's annual gas consumption. The way out of the dilemma is to increase road use efficiency as well as improve mass transportation alternatives.

  17. Roadless and Low-Traffic Areas as Conservation Targets in Europe.

    PubMed

    Selva, Nuria; Kreft, Stefan; Kati, Vassiliki; Schluck, Martin; Jonsson, Bengt-Gunnar; Mihok, Barbara; Okarma, Henryk; Ibisch, Pierre L

    2011-11-01

    With increasing road encroachment, habitat fragmentation by transport infrastructures has been a serious threat for European biodiversity. Areas with no roads or little traffic ("roadless and low-traffic areas") represent relatively undisturbed natural habitats and functioning ecosystems. They provide many benefits for biodiversity and human societies (e.g., landscape connectivity, barrier against pests and invasions, ecosystem services). Roadless and low-traffic areas, with a lower level of anthropogenic disturbances, are of special relevance in Europe because of their rarity and, in the context of climate change, because of their contribution to higher resilience and buffering capacity within landscape ecosystems. An analysis of European legal instruments illustrates that, although most laws aimed at protecting targets which are inherent to fragmentation, like connectivity, ecosystem processes or integrity, roadless areas are widely neglected as a legal target. A case study in Germany underlines this finding. Although the Natura 2000 network covers a significant proportion of the country (16%), Natura 2000 sites are highly fragmented and most low-traffic areas (75%) lie unprotected outside this network. This proportion is even higher for the old Federal States (western Germany), where only 20% of the low-traffic areas are protected. We propose that the few remaining roadless and low-traffic areas in Europe should be an important focus of conservation efforts; they should be urgently inventoried, included more explicitly in the law and accounted for in transport and urban planning. Considering them as complementary conservation targets would represent a concrete step towards the strengthening and adaptation of the Natura 2000 network to climate change.

  18. Human resources for the control of road traffic injury.

    PubMed Central

    Mock, Charles; Kobusingye, Olive; Anh, Le Vu; Afukaar, Francis; Arreola-Risa, Carlos

    2005-01-01

    The definition of the ideal numbers and distribution of human resources required for control of road traffic injury (RTI) is not as advanced as for other health problems. We can nonetheless identify functions that need to be addressed across the spectrum of injury control: surveillance; road safety (including infrastructure, vehicle design, and behaviour); and trauma care. Many low-cost strategies to improve these functions in low- or middle-income countries can be identified. For all these strategies, there is need for adequate institutional capacity, including funding, legal authority, and human resources. Several categories of human resources need to be developed: epidemiologists who can handle injury data, design surveillance systems, and undertake research; engineers and planners versed in safety aspects of road design, traffic flow, urban planning, and vehicle design; police and lawyers who understand the health impact of traffic law; clinicians who can develop cost-effective improvements in the entire system of trauma treatment; media experts to undertake effective behaviour change and social marketing; and economists to assist with cost-effectiveness evaluations. RTI control can be strengthened by enhancing such training in these disciplines, as well as encouraging retention of those who have the needed skills. Mechanisms to enhance collaboration between these different fields need to be promoted. Finally, the burden of RTI is borne disproportionately by the poor; in addition to technical issues, more profound equity issues must be addressed. This mandates that people from all professional backgrounds who work for RTI control should develop skills in advocacy and politics. PMID:15868021

  19. Forecast of the general aviation air traffic control environment for the 1980's

    NASA Technical Reports Server (NTRS)

    Hoffman, W. C.; Hollister, W. M.

    1976-01-01

    The critical information required for the design of a reliable, low cost, advanced avionics system which would enhance the safety and utility of general aviation is stipulated. Sufficient data is accumulated upon which industry can base the design of a reasonably priced system having the capability required by general aviation in and beyond the 1980's. The key features of the Air Traffic Control (ATC) system are: a discrete address beacon system, a separation assurance system, area navigation, a microwave landing system, upgraded ATC automation, airport surface traffic control, a wake vortex avoidance system, flight service stations, and aeronautical satellites. The critical parameters that are necessary for component design are identified. The four primary functions of ATC (control, surveillance, navigation, and communication) and their impact on the onboard avionics system design are assessed.

  20. Air traffic controllers' long-term speech-in-noise training effects: A control group study.

    PubMed

    Zaballos, Maria T P; Plasencia, Daniel P; González, María L Z; de Miguel, Angel R; Macías, Ángel R

    2016-01-01

    Speech perception in noise relies on the capacity of the auditory system to process complex sounds using sensory and cognitive skills. The possibility that these can be trained during adulthood is of special interest in auditory disorders, where speech in noise perception becomes compromised. Air traffic controllers (ATC) are constantly exposed to radio communication, a situation that seems to produce auditory learning. The objective of this study has been to quantify this effect. 19 ATC and 19 normal hearing individuals underwent a speech in noise test with three signal to noise ratios: 5, 0 and -5 dB. Noise and speech were presented through two different loudspeakers in azimuth position. Speech tokes were presented at 65 dB SPL, while white noise files were at 60, 65 and 70 dB respectively. Air traffic controllers outperform the control group in all conditions [P<0.05 in ANOVA and Mann-Whitney U tests]. Group differences were largest in the most difficult condition, SNR=-5 dB. However, no correlation between experience and performance were found for any of the conditions tested. The reason might be that ceiling performance is achieved much faster than the minimum experience time recorded, 5 years, although intrinsic cognitive abilities cannot be disregarded. ATC demonstrated enhanced ability to hear speech in challenging listening environments. This study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions, although good cognitive qualities are likely to be a basic requirement for this training to be effective. Our results show that ATC outperform the control group in all conditions. Thus, this study provides evidence that long-term auditory training is indeed useful in achieving better speech-in-noise understanding even in adverse conditions.

  1. A generic approach for examining the effectiveness of traffic control devices in school zones.

    PubMed

    Zhao, Xiaohua; Li, Jiahui; Ding, Han; Zhang, Guohui; Rong, Jian

    2015-09-01

    The effectiveness and performance of traffic control devices in school zones have been impacted significantly by many factors, such as driver behavioral attributes, roadway geometric features, environmental characteristics, weather and visibility conditions, region-wide traffic regulations and policies, control modes, etc. When deploying traffic control devices in school zones, efforts are needed to clarify: (1) whether traffic control device installation is warranted; and (2) whether other device effectively complements this traffic control device and strengthens its effectiveness. In this study, a generic approach is developed to examine and evaluate the effectiveness of various traffic control devices deployed in school zones through driving simulator-based experiments. A Traffic Control Device Selection Model (TCDSM) is developed and two representative school zones are selected as the testbed in Beijing for driving simulation implementation to enhance its applicability. Statistical analyses are conducted to extract the knowledge from test data recorded by a driving simulator. Multiple measures of effectiveness (MOEs) are developed and adopted including average speed, relative speed difference, and standard deviation of acceleration for traffic control device performance quantification. The experimental tests and analysis results reveal that the appropriateness of the installation of certain traffic control devices can be statistically verified by TCDSM. The proposed approach provides a generic framework to assess traffic control device performance in school zones including experiment design, statistical formulation, data analysis, simulation model implementation, data interpretation, and recommendation development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Analysis of routine communication in the air traffic control system

    NASA Technical Reports Server (NTRS)

    Clark, Herbert H.; Morrow, Daniel; Rodvoid, Michelle

    1990-01-01

    The present project has three related goals. The first is to describe the organization of routine controller-pilot communication. This includes identifying the basic units of communication and how they are organized into discourse, how controllers and pilots use language to achieve their goals, and what topics they discuss. The second goal is to identify the type and frequency of problems that interrupt routine information transfer and prompt pilots and controllers to focus on the communication itself. The authors analyze the costs of these problems in terms of communication efficiency, and the techniques used to resolve these problems. Third, the authors hope to identify factors associated with communication problems, such as deviations from conventional air traffic control procedures.

  3. Analysis of routine communication in the air traffic control system

    NASA Astrophysics Data System (ADS)

    Clark, Herbert H.; Morrow, Daniel; Rodvoid, Michelle

    1990-08-01

    The present project has three related goals. The first is to describe the organization of routine controller-pilot communication. This includes identifying the basic units of communication and how they are organized into discourse, how controllers and pilots use language to achieve their goals, and what topics they discuss. The second goal is to identify the type and frequency of problems that interrupt routine information transfer and prompt pilots and controllers to focus on the communication itself. The authors analyze the costs of these problems in terms of communication efficiency, and the techniques used to resolve these problems. Third, the authors hope to identify factors associated with communication problems, such as deviations from conventional air traffic control procedures.

  4. An augmented reality binocular system (ARBS) for air traffic controllers

    NASA Astrophysics Data System (ADS)

    Fulbrook, Jim E.; Ruffner, John W.; Labbe, Roger

    2008-04-01

    The primary means by which air traffic tower controllers obtain information is through direct out-thewindow viewing, although a considerable amount of time is spent looking at electronic displays and other information sources inside the tower cab. The Air Force Research Laboratory sponsored the development of a prototype Augmented Reality Binocular System (ARBS) that enhances tower controller performance, situation awareness, and safety. The ARBS is composed of a virtual binocular (VB) that displays real-time imagery from high resolution telephoto cameras and sensors mounted on pan/tilt units (PTUs). The selected PTU tracks to the movement of the VB, which has an inertial heading and elevation sensor. Relevant airfield situation text and graphic depictions that identify airfield features are overlaid on the imagery. In addition, the display is capable of labeling and tracking vehicles on which an Automatic Dependent Surveillance - Broadcast (ADS-B) system has been installed. The ARBS provides air traffic controllers and airfield security forces with the capability to orient toward, observe, and conduct continuous airfield operations and surveillance/security missions from any number of viewing aspects in limited visibility conditions. In this paper, we describe the ARBS in detail, discuss the results of a Usability Test of the prototype ARBS, and discuss ideas for follow-on efforts to develop the ARBS to a fieldable level.

  5. A passive brain-computer interface application for the mental workload assessment on professional air traffic controllers during realistic air traffic control tasks.

    PubMed

    Aricò, P; Borghini, G; Di Flumeri, G; Colosimo, A; Pozzi, S; Babiloni, F

    2016-01-01

    In the last decades, it has been a fast-growing concept in the neuroscience field. The passive brain-computer interface (p-BCI) systems allow to improve the human-machine interaction (HMI) in operational environments, by using the covert brain activity (eg, mental workload) of the operator. However, p-BCI technology could suffer from some practical issues when used outside the laboratories. In particular, one of the most important limitations is the necessity to recalibrate the p-BCI system each time before its use, to avoid a significant reduction of its reliability in the detection of the considered mental states. The objective of the proposed study was to provide an example of p-BCIs used to evaluate the users' mental workload in a real operational environment. For this purpose, through the facilities provided by the École Nationale de l'Aviation Civile of Toulouse (France), the cerebral activity of 12 professional air traffic control officers (ATCOs) has been recorded while performing high realistic air traffic management scenarios. By the analysis of the ATCOs' brain activity (electroencephalographic signal-EEG) and the subjective workload perception (instantaneous self-assessment) provided by both the examined ATCOs and external air traffic control experts, it has been possible to estimate and evaluate the variation of the mental workload under which the controllers were operating. The results showed (i) a high significant correlation between the neurophysiological and the subjective workload assessment, and (ii) a high reliability over time (up to a month) of the proposed algorithm that was also able to maintain high discrimination accuracies by using a low number of EEG electrodes (~3 EEG channels). In conclusion, the proposed methodology demonstrated the suitability of p-BCI systems in operational environments and the advantages of the neurophysiological measures with respect to the subjective ones. © 2016 Elsevier B.V. All rights reserved.

  6. Risk factors in highway traffic accidents: a case control study.

    PubMed

    Hijar, M; Carrillo, C; Flores, M; Anaya, R; Lopez, V

    2000-09-01

    The objective of this study was to identify risk factors related to the driver, the vehicle and the environment, that are associated with motor vehicles accidents on highways. A case and control design was used where the case was: the driver of a motor vehicle who was involved in an accident while traveling on the Mexico-Cuernavaca highway; and the control was: the driver or a motor vehicle who, traveling on the highway, completed the trip without being involved in a traffic accident. Risk factors associated with the occurrence of a traffic accident (P > 0.05) were: age under 25 years, frequent travel, traveling to work, alcohol consumption, driving during the daylight, on a week-day, under adverse weather conditions and in the Mexico Cuernavaca direction of road. Risks adjusted by logistic regression were: age under 25 years odds ratio (OR) 3.01, confidence interval (CI) (95%) 1.46-6.18; work as a travel reason OR 1.74, CI 1.06 2.86; alcohol intake OR 4.70, Cl 1.62 13.6; driving under adverse weather conditions OR 5.70, CI 3.66-8.85; traveling on a week-day OR 1.84, CI 1.14-2.94; during daylight hours OR 4.23, CI 2.36-7.58 and in the Mexico Cuernavaca direction of road OR 2.69, CI 1.67 4.32. The identification of factors associated with the risk of being involved in a highway traffic accident allows us to propose primary prevention measures for this important public health problem.

  7. Method to Quantify the Visibility of Traffic Signals for Driver Assistance

    NASA Astrophysics Data System (ADS)

    Kimura, Fumika; Mekada, Yoshito; Takahashi, Tomokazu; Ide, Ichiro; Murase, Hiroshi; Tamatsu, Yukimasa

    We propose a method to recognize the visibility of traffic signals from a driver's perspective. The more that driver assistance systems are equipped for practical use, the more information that is being provided for drivers. So each information provision system should select appropriate information based on the situation. Our goal is to realize a system that quantifies the visibility of traffic signals from images taken by in-vehicle cameras and appropriately provides information to drivers. In this paper, we propose a method to measure visibility by two criterions, detectability and discriminability. Each index is computed using image processing techniques. Experiments using actual images showed that the proposed indices correspond well to human perception.

  8. A Cooperative Traffic Control of Vehicle–Intersection (CTCVI) for the Reduction of Traffic Delays and Fuel Consumption

    PubMed Central

    Li, Jinjian; Dridi, Mahjoub; El-Moudni, Abdellah

    2016-01-01

    The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP) to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes. PMID:27999333

  9. A Cooperative Traffic Control of Vehicle-Intersection (CTCVI) for the Reduction of Traffic Delays and Fuel Consumption.

    PubMed

    Li, Jinjian; Dridi, Mahjoub; El-Moudni, Abdellah

    2016-12-17

    The problem of reducing traffic delays and decreasing fuel consumption simultaneously in a network of intersections without traffic lights is solved by a cooperative traffic control algorithm, where the cooperation is executed based on the connection of Vehicle-to-Infrastructure (V2I). This resolution of the problem contains two main steps. The first step concerns the itinerary of which intersections are chosen by vehicles to arrive at their destination from their starting point. Based on the principle of minimal travel distance, each vehicle chooses its itinerary dynamically based on the traffic loads in the adjacent intersections. The second step is related to the following proposed cooperative procedures to allow vehicles to pass through each intersection rapidly and economically: on one hand, according to the real-time information sent by vehicles via V2I in the edge of the communication zone, each intersection applies Dynamic Programming (DP) to cooperatively optimize the vehicle passing sequence with minimal traffic delays so that the vehicles may rapidly pass the intersection under the relevant safety constraints; on the other hand, after receiving this sequence, each vehicle finds the optimal speed profiles with the minimal fuel consumption by an exhaustive search. The simulation results reveal that the proposed algorithm can significantly reduce both travel delays and fuel consumption compared with other papers under different traffic volumes.

  10. Semiautomated Management Of Arriving Air Traffic

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz; Nedell, William

    1992-01-01

    System of computers, graphical workstations, and computer programs developed for semiautomated management of approach and arrival of numerous aircraft at airport. System comprises three subsystems: traffic-management advisor, used for controlling traffic into terminal area; descent advisor generates information integrated into plan-view display of traffic on monitor; and final-approach-spacing tool used to merge traffic converging on final approach path while making sure aircraft are properly spaced. Not intended to restrict decisions of air-traffic controllers.

  11. Using all-way stop control for residential traffic management. Final report, September 1991-December 1995

    SciTech Connect

    Cottrell, B.H.

    1996-01-01

    All-way, or multiway, stop signs are perhaps the most controversial form of residential traffic control. Residents are likely to request all-way stop signs more frequently than any other form of control. Stop signs are thought of as panaceas for many traffic problems. The Virginia Department of Transportation (VDOT) receives requests for all-way stop control (AWSC) on residential streets primarily to slow traffic, but also to reduce cut-through traffic. The objective of this study was to evaluate the effectiveness of AWSC for residential traffic management. The study was limited to the use of AWSC on local residential streets. A comprehensive review of the literature and a questionnaire survey of selected traffic engineering agencies were conducted to identify current use of AWSC. Three case studies using a series of AWSC intersections to reduce cut-through traffic on local residential streets were analyzed.

  12. A controllable water signal transistor.

    PubMed

    Wu, Lili; Zhou, Xiaoyan; Lu, Hangjun; Liang, Qing; Kou, Jianlong; Wu, Fengmin; Fan, Jintu

    2017-03-27

    We performed molecular dynamics simulations to study the regulating ability of water chains confined in a Y-shaped nanochannel. It was shown that a signal at the molecular level could be controlled by two other charge-induced signals when the water chains were confined in a Y-shaped nanochannel, demonstrating promising applications as water signal transistors in nanosignal systems. The mechanism of a water signal transistor is similar to a signal logic device. This remarkable ability to control the water signal is attributed to the strong dipole-ordering of the water chains in the nanochannel. The controllable water signal process of the Y-shaped nanochannel provides opportunities for future application in the design of molecular-scale signal devices.

  13. The effect of communications and traffic situation displays on pilots awareness of traffic in the terminal area

    NASA Technical Reports Server (NTRS)

    Melanson, D.; Curry, R. E.; Howell, J. D.; Connelly, M. E.

    1973-01-01

    The Air Traffic Control (ATC) system is evolving under a general plan specified by the Federal Aviation Administration. Among the developments being considered is the Discrete Address Beacon System (DABS). The use of this system, although relieving congestion on the communications frequencies, would eliminate information about other aircraft because the party line communications now in use would be lost. One alternative to restore this lost information is an Airborne Traffic Situation Display (TSD). Experienced airline and military pilots participated in a factorial design to evaluate two types of communication (discrete address, party line) and two types of displays (TSD, no TSD). A stop-action quiz was used to evaluate their knowledge of other aircrafts' position, altitude, speed, heading, rate of climb, identity, and landing sequence number. Significant differences between conditions were detected, primarily in the position variables. Workload, as measured by a spare capacity side-task, showed a main effect of displays and a significant interaction between displays and communications. The data are summarized by plotting each display/communication condition configuration in the plane defined by information and workload index. A limited number of blunders by other aircraft were included in the simulations with a significant, but not entirely satisfactory, improvement in blunder detection attributed to the TSD.

  14. 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.

  15. Attentional costs and failures in air traffic control notifications.

    PubMed

    Imbert, Jean-Paul; Hodgetts, Helen M; Parise, Robert; Vachon, François; Dehais, Frédéric; Tremblay, Sébastien

    2014-01-01

    Large display screens are common in supervisory tasks, meaning that alerts are often perceived in peripheral vision. Five air traffic control notification designs were evaluated in their ability to capture attention during an ongoing supervisory task, as well as their impact on the primary task. A range of performance measures, eye-tracking and subjective reports showed that colour, even animated, was less effective than movement, and notifications sometimes went unnoticed. Designs that drew attention to the notified aircraft by a pulsating box, concentric circles or the opacity of the background resulted in faster perception and no missed notifications. However, the latter two designs were intrusive and impaired primary task performance, while the simpler animated box captured attention without an overhead cognitive cost. These results highlight the need for a holistic approach to evaluation, achieving a balance between the benefits for one aspect of performance against the potential costs for another. Practitioner summary: We performed a holistic examination of air traffic control notification designs regarding their ability to capture attention during an ongoing supervisory task. The combination of performance, eye-tracking and subjective measurements demonstrated that the best design achieved a balance between attentional power and the overhead cognitive cost to primary task performance.

  16. Trajectory Specification for High-Capacity Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Paielli, Russell A.

    2004-01-01

    In the current air traffic management system, the fundamental limitation on airspace capacity is the cognitive ability of human air traffic controllers to maintain safe separation with high reliability. The doubling or tripling of airspace capacity that will be needed over the next couple of decades will require that tactical separation be at least partially automated. Standardized conflict-free four-dimensional trajectory assignment will be needed to accomplish that objective. A trajectory specification format based on the Extensible Markup Language is proposed for that purpose. This format can be used to downlink a trajectory request, which can then be checked on the ground for conflicts and approved or modified, if necessary, then uplinked as the assigned trajectory. The horizontal path is specified as a series of geodetic waypoints connected by great circles, and the great-circle segments are connected by turns of specified radius. Vertical profiles for climb and descent are specified as low-order polynomial functions of along-track position, which is itself specified as a function of time. Flight technical error tolerances in the along-track, cross-track, and vertical axes define a bounding space around the reference trajectory, and conformance will guarantee the required separation for a period of time known as the conflict time horizon. An important safety benefit of this regimen is that the traffic will be able to fly free of conflicts for at least several minutes even if all ground systems and the entire communication infrastructure fail. Periodic updates in the along-track axis will adjust for errors in the predicted along-track winds.

  17. Wide-Area Traffic Management for Cloud Services

    DTIC Science & Technology

    2012-04-01

    100 xiii Chapter 1 Introduction The Internet is increasingly a platform for online services—such as Web search, social networks, multiplayer games ... online service has specific performance requirements. For example, Web search and multi- player games need low end-to-end latency; video streaming...ective ways to distribute content across wide area networks. Providing large-scale, geographically-replicated online services presents new opportunities

  18. 19 CFR 113.66 - Control of containers and instruments of international traffic bond conditions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Control of containers and instruments of... Control of containers and instruments of international traffic bond conditions. A bond for control of... shall be a continuous bond. Control of Containers and Instruments of International Traffic...

  19. 19 CFR 113.66 - Control of containers and instruments of international traffic bond conditions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Control of containers and instruments of... Control of containers and instruments of international traffic bond conditions. A bond for control of... shall be a continuous bond. Control of Containers and Instruments of International Traffic...

  20. 19 CFR 113.66 - Control of containers and instruments of international traffic bond conditions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Control of containers and instruments of... Control of containers and instruments of international traffic bond conditions. A bond for control of... shall be a continuous bond. Control of Containers and Instruments of International Traffic...

  1. 19 CFR 113.66 - Control of containers and instruments of international traffic bond conditions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Control of containers and instruments of... Control of containers and instruments of international traffic bond conditions. A bond for control of... shall be a continuous bond. Control of Containers and Instruments of International Traffic...

  2. EEG-Based Cognitive Control Behaviour Assessment: an Ecological study with Professional Air Traffic Controllers.

    PubMed

    Borghini, Gianluca; Aricò, Pietro; Di Flumeri, Gianluca; Cartocci, Giulia; Colosimo, Alfredo; Bonelli, Stefano; Golfetti, Alessia; Imbert, Jean Paul; Granger, Géraud; Benhacene, Railane; Pozzi, Simone; Babiloni, Fabio

    2017-04-03

    Several models defining different types of cognitive human behaviour are available. For this work, we have selected the Skill, Rule and Knowledge (SRK) model proposed by Rasmussen in 1983. This model is currently broadly used in safety critical domains, such as the aviation. Nowadays, there are no tools able to assess at which level of cognitive control the operator is dealing with the considered task, that is if he/she is performing the task as an automated routine (skill level), as procedures-based activity (rule level), or as a problem-solving process (knowledge level). Several studies tried to model the SRK behaviours from a Human Factor perspective. Despite such studies, there are no evidences in which such behaviours have been evaluated from a neurophysiological point of view, for example, by considering brain activity variations across the different SRK levels. Therefore, the proposed study aimed to investigate the use of neurophysiological signals to assess the cognitive control behaviours accordingly to the SRK taxonomy. The results of the study, performed on 37 professional Air Traffic Controllers, demonstrated that specific brain features could characterize and discriminate the different SRK levels, therefore enabling an objective assessment of the degree of cognitive control behaviours in realistic settings.

  3. Simulation studies of STOL airplane operations in metropolitan downtown and airport air traffic control environments

    NASA Technical Reports Server (NTRS)

    Sawyer, R. H.; Mclaughlin, M. D.

    1974-01-01

    The operating problems and equipment requirements for STOL airplanes in terminal area operations in simulated air traffic control (ATC) environments were studied. These studies consisted of Instrument Flight Rules (IFR) arrivals and departures in the New York area to and from a downtown STOL port, STOL runways at John F. Kennedy International Airport, or STOL runways at a hypothetical international airport. The studies were accomplished in real time by using a STOL airplane flight simulator. An experimental powered lift STOL airplane and two in-service airplanes having high aerodynamic lift (i.e., STOL) capability were used in the simulations.

  4. Estimation of red-light running frequency using high-resolution traffic and signal data.

    PubMed

    Chen, Peng; Yu, Guizhen; Wu, Xinkai; Ren, Yilong; Li, Yueguang

    2017-03-23

    Red-light-running (RLR) emerges as a major cause that may lead to intersection-related crashes and endanger intersection safety. To reduce RLR violations, it's critical to identify the influential factors associated with RLR and estimate RLR frequency. Without resorting to video camera recordings, this study investigates this important issue by utilizing high-resolution traffic and signal event data collected from loop detectors at five intersections on Trunk Highway 55, Minneapolis, MN. First, a simple method is proposed to identify RLR by fully utilizing the information obtained from stop bar detectors, downstream entrance detectors and advance detectors. Using 12 months of event data, a total of 6550 RLR cases were identified. According to a definition of RLR frequency as the conditional probability of RLR on a certain traffic or signal condition (veh/1000veh), the relationships between RLR frequency and some influential factors including arriving time at advance detector, approaching speed, headway, gap to the preceding vehicle on adjacent lane, cycle length, geometric characteristics and even snowing weather were empirically investigated. Statistical analysis shows good agreement with the traffic engineering practice, e.g., RLR is most likely to occur on weekdays during peak periods under large traffic demands and longer signal cycles, and a total of 95.24% RLR events occurred within the first 1.5s after the onset of red phase. The findings confirmed that vehicles tend to run the red light when they are close to intersection during phase transition, and the vehicles following the leading vehicle with short headways also likely run the red light. Last, a simplified nonlinear regression model is proposed to estimate RLR frequency based on the data from advance detector. The study is expected to helpbetter understand RLR occurrence and further contribute to the future improvement of intersection safety.

  5. Air Route Traffic Control Center. Controller Over-The-Shoulder Training Review: Instruction Manual.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    The instruction manual provides 12 step-by-step instructions for air traffic control supervisors in conducting over-the-shoulder training observations of enroute center controllers. Since the primary purpose of the review is to quickly identify training needs and requirements, the control responsibilities are approached from a deficiency…

  6. Lattice hydrodynamic model based traffic control: A transportation cyber-physical system approach

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Sun, Dihua; Liu, Weining

    2016-11-01

    Lattice hydrodynamic model is a typical continuum traffic flow model, which describes the jamming transition of traffic flow properly. Previous studies in lattice hydrodynamic model have shown that the use of control method has the potential to improve traffic conditions. In this paper, a new control method is applied in lattice hydrodynamic model from a transportation cyber-physical system approach, in which only one lattice site needs to be controlled in this control scheme. The simulation verifies the feasibility and validity of this method, which can ensure the efficient and smooth operation of the traffic flow.

  7. Instructional Strategies for Teaching Judgment in Detecting Gaps for Crossing Streets with No Traffic Controls

    ERIC Educational Resources Information Center

    Sauerbuger, Dona

    2006-01-01

    This article provides instructional strategies for the concepts and skills of crossing streets that have no stop sign or traffic signal. Such situations include crossing the main street at intersections with stop signs for the secondary street, at roundabouts or traffic circles, separate right-turn lanes, and mid-block crosswalks. In these…

  8. Instructional Strategies for Teaching Judgment in Detecting Gaps for Crossing Streets with No Traffic Controls

    ERIC Educational Resources Information Center

    Sauerbuger, Dona

    2006-01-01

    This article provides instructional strategies for the concepts and skills of crossing streets that have no stop sign or traffic signal. Such situations include crossing the main street at intersections with stop signs for the secondary street, at roundabouts or traffic circles, separate right-turn lanes, and mid-block crosswalks. In these…

  9. Piloted simulation of a ground-based time-control concept for air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Green, Steven M.

    1989-01-01

    A concept for aiding air traffic controllers in efficiently spacing traffic and meeting scheduled arrival times at a metering fix was developed and tested in a real time simulation. The automation aid, referred to as the ground based 4-D descent advisor (DA), is based on accurate models of aircraft performance and weather conditions. The DA generates suggested clearances, including both top-of-descent-point and speed-profile data, for one or more aircraft in order to achieve specific time or distance separation objectives. The DA algorithm is used by the air traffic controller to resolve conflicts and issue advisories to arrival aircraft. A joint simulation was conducted using a piloted simulator and an advanced concept air traffic control simulation to study the acceptability and accuracy of the DA automation aid from both the pilot's and the air traffic controller's perspectives. The results of the piloted simulation are examined. In the piloted simulation, airline crews executed controller issued descent advisories along standard curved path arrival routes, and were able to achieve an arrival time precision of + or - 20 sec at the metering fix. An analysis of errors generated in turns resulted in further enhancements of the algorithm to improve the predictive accuracy. Evaluations by pilots indicate general support for the concept and provide specific recommendations for improvement.

  10. 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.

  11. Communication efficiency and congestion of signal traffic in large-scale brain networks.

    PubMed

    Mišić, Bratislav; Sporns, Olaf; McIntosh, Anthony R

    2014-01-01

    The complex connectivity of the cerebral cortex suggests that inter-regional communication is a primary function. Using computational modeling, we show that anatomical connectivity may be a major determinant for global information flow in brain networks. A macaque brain network was implemented as a communication network in which signal units flowed between grey matter nodes along white matter paths. Compared to degree-matched surrogate networks, information flow on the macaque brain network was characterized by higher loss rates, faster transit times and lower throughput, suggesting that neural connectivity may be optimized for speed rather than fidelity. Much of global communication was mediated by a "rich club" of hub regions: a sub-graph comprised of high-degree nodes that are more densely interconnected with each other than predicted by chance. First, macaque communication patterns most closely resembled those observed for a synthetic rich club network, but were less similar to those seen in a synthetic small world network, suggesting that the former is a more fundamental feature of brain network topology. Second, rich club regions attracted the most signal traffic and likewise, connections between rich club regions carried more traffic than connections between non-rich club regions. Third, a number of rich club regions were significantly under-congested, suggesting that macaque connectivity actively shapes information flow, funneling traffic towards some nodes and away from others. Together, our results indicate a critical role of the rich club of hub nodes in dynamic aspects of global brain communication.

  12. Flight tests using data link for air traffic control and weather information exchange

    NASA Technical Reports Server (NTRS)

    Knox, Charles E.; Scanlon, Charles H.

    1990-01-01

    Message exchange for air traffic control (ATC) purposes via data link offers the potential benefits of increasing the airspace system safety and efficiency. This is accomplished by reducing communication errors and relieving the overloaded ATC radio frequencies, which hamper efficient message exchanges during peak traffic periods in many busy terminal areas. However, the many uses and advantages of data link create additional questions concerning the interface among the human-users and the cockpit and ground systems. A flight test was conducted in the NASA Langley B-737 airplane to contrast flight operations using current voice communications with the use of data link for transmitting both strategic and tactical ATC clearances during a typical commercial airline flight from takeoff to landing. Commercial airplane pilots were used as test subjects.

  13. The Dynamic Planner: The Sequencer, Scheduler, and Runway Allocator for Air Traffic Control Automation

    NASA Technical Reports Server (NTRS)

    Wong, Gregory L.; Denery, Dallas (Technical Monitor)

    2000-01-01

    The Dynamic Planner (DP) has been designed, implemented, and integrated into the Center-TRACON Automation System (CTAS) to assist Traffic Management Coordinators (TMCs), in real time, with the task of planning and scheduling arrival traffic approximately 35 to 200 nautical miles from the destination airport. The TMC may input to the DP a series of current and future scheduling constraints that reflect the operation and environmental conditions of the airspace. Under these constraints, the DP uses flight plans, track updates, and Estimated Time of Arrival (ETA) predictions to calculate optimal runway assignments and arrival schedules that help ensure an orderly, efficient, and conflict-free flow of traffic into the terminal area. These runway assignments and schedules can be shown directly to controllers or they can be used by other CTAS tools to generate advisories to the controllers. Additionally, the TMC and controllers may override the decisions made by the DP for tactical considerations. The DP will adapt to computations to accommodate these manual inputs.

  14. 32 CFR 245.17 - U.S. civil and military air traffic control facilities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT... EATPL, or must have been granted a Security Control Authorization. (c) Disseminate instructions and... 32 National Defense 2 2012-07-01 2012-07-01 false U.S. civil and military air traffic control...

  15. 32 CFR 245.17 - U.S. civil and military air traffic control facilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT... EATPL, or must have been granted a Security Control Authorization. (c) Disseminate instructions and... 32 National Defense 2 2011-07-01 2011-07-01 false U.S. civil and military air traffic control...

  16. 32 CFR 245.17 - U.S. civil and military air traffic control facilities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT... EATPL, or must have been granted a Security Control Authorization. (c) Disseminate instructions and... 32 National Defense 2 2014-07-01 2014-07-01 false U.S. civil and military air traffic control...

  17. 32 CFR 245.17 - U.S. civil and military air traffic control facilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT... EATPL, or must have been granted a Security Control Authorization. (c) Disseminate instructions and... 32 National Defense 2 2010-07-01 2010-07-01 false U.S. civil and military air traffic control...

  18. 32 CFR 245.17 - U.S. civil and military air traffic control facilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT... EATPL, or must have been granted a Security Control Authorization. (c) Disseminate instructions and... 32 National Defense 2 2013-07-01 2013-07-01 false U.S. civil and military air traffic control...

  19. The Effect of Stereoscopic Presentation on a Simulated Air Traffic Control Task

    DTIC Science & Technology

    1989-12-01

    B87-17 No. in Program of Work : 731.3 SUMMARY Collision prediction in a simulated Air Traffic Control (ATC) task was compared for conditions in...increasing density and complexity of air traffic, the work load in Air Traffic Control (ATC) has become a matter of great concern. One of the factors that...three-dimensional space he is working in, should be welcome. One possibility would be colour coding, an application that has finally become well

  20. An Adaptive Fuzzy-Logic Traffic Control System in Conditions of Saturated Transport Stream

    PubMed Central

    Marakhimov, A. R.; Igamberdiev, H. Z.; Umarov, Sh. X.

    2016-01-01

    This paper considers the problem of building adaptive fuzzy-logic traffic control systems (AFLTCS) to deal with information fuzziness and uncertainty in case of heavy traffic streams. Methods of formal description of traffic control on the crossroads based on fuzzy sets and fuzzy logic are proposed. This paper also provides efficient algorithms for implementing AFLTCS and develops the appropriate simulation models to test the efficiency of suggested approach. PMID:27517081

  1. Characterizing spatial variability of air pollution from vehicle traffic around the Houston Ship Channel area

    NASA Astrophysics Data System (ADS)

    Zhang, Xueying; Craft, Elena; Zhang, Kai

    2017-07-01

    Mobile emissions are a major source of urban air pollution and have been associated with a variety of adverse health outcomes. The Houston Ship Channel area is the home of a large number of diesel-powered vehicles emitting fine particulate matter (PM2.5; ≤2.5 μm in aerodynamic diameter) and nitrogen oxides (NOx). However, the spatial variability of traffic-related air pollutants in the Houston Ship Channel area has rarely been investigated. The objective of this study is to characterize spatial variability of PM2.5 and NOx concentrations attributable to on-road traffic in the Houston Ship Channel area in the year of 2011. We extracted the road network from the Texas Department of Transportation Road Inventory, and calculated emission rates using the Motor Vehicle Emission Simulator version 2014a (MOVES2014a). These parameters and preprocessed meteorological parameters were entered into a Research LINE-source Dispersion Model (RLINE) to conduct a simulation. Receptors were placed at 50 m resolution within 300 m to major roads and at 150 m resolution in the rest of the area. Our findings include that traffic-related PM2.5 were mainly emitted from trucks, while traffic-related NOx were emitted from both trucks and cars. The traffic contributed 0.90 μg/m3 PM2.5 and 29.23 μg/m3 NOx to the annual average mass concentrations of on-road air pollution, and the concentrations of the two pollutants decreased by nearly 40% within 500 m distance to major roads. The pollution level of traffic-related PM2.5 and NOx was higher in winter than those in the other three seasons. The Houston Ship Channel has earlier morning peak hours and relative late afternoon hours, which indicates the influence of goods movement from port activity. The varied near-road gradients illustrate that proximities to major roads are not an accurate surrogate of traffic-related air pollution.

  2. Development concerns for satellite-based air traffic control surveillance systems

    NASA Technical Reports Server (NTRS)

    Mcdonald, K. D.

    1985-01-01

    Preliminary results of an investigation directed toward the configuration of a practical system design which can form the baseline for assessing the applications and value of a satellite based air traffic surveillance system for future use in the National Airspace System (NAS) are described. This work initially studied the characteristics and capabilities of a satellite configuration which would operate compatibly with the signal structure and avionics of the next generation air traffic control secondary surveillance radar system, the Mode S system. A compatible satellite surveillance system concept is described and an analysis is presented of the link budgets for the various transmission paths. From this, the satellite characteristics are established involving a large multiple feed L band antenna of approximately 50 meter aperture dimension. Trade offs involved in several of the alternative large aperture antennas considered are presented as well as the influence of various antenna configurations on the performance capabilities of the surveillance system. The features and limitations of the use of large aperture antenna systems for air traffic surveillance are discussed. Tentative results of this continuing effort are summarized with a brief description of follow on investigations involving other space based antenna systems concepts.

  3. Feasibility of satellite interferometry for surveillance, navigation, and traffic control

    NASA Technical Reports Server (NTRS)

    Gopalapillai, S.; Ruck, G. T.; Mourad, A. G.

    1976-01-01

    The feasibility of using a satellite borne interferometry system for surveillance, navigation, and traffic control applications was investigated. The evaluation was comprised of: (1) a two part systems analysis (software and hardware); (2) a survey of competitive navigation systems (both experimental and planned); (3) a comparison of their characteristics and capabilities with those of an interferometry system; and (4) a limited survey of potential users to determine the variety of possible applications for the interferometry system and the requirements which it would have to meet. Five candidate or "strawman" interferometry systems for various applications with various capabilities were configured (on a preliminary basis) and were evaluated. It is concluded that interferometry in conjunction with a geostationary satellite has an inherent ability to provide both a means for navigation/position location and communication. It offers a very high potential for meeting a large number of user applications and requirements for navigation and related functions.

  4. Optimization and Planning of Emergency Evacuation Routes Considering Traffic Control

    PubMed Central

    Zhang, Lijun; Wang, Zhaohua

    2014-01-01

    Emergencies, especially major ones, happen fast, randomly, as well as unpredictably, and generally will bring great harm to people's life and the economy. Therefore, governments and lots of professionals devote themselves to taking effective measures and providing optimal evacuation plans. This paper establishes two different emergency evacuation models on the basis of the maximum flow model (MFM) and the minimum-cost maximum flow model (MC-MFM), and proposes corresponding algorithms for the evacuation from one source node to one designated destination (one-to-one evacuation). Ulteriorly, we extend our evaluation model from one source node to many designated destinations (one-to-many evacuation). At last, we make case analysis of evacuation optimization and planning in Beijing, and obtain the desired evacuation routes and effective traffic control measures from the perspective of sufficiency and practicability. Both analytical and numerical results support that our models are feasible and practical. PMID:24991636

  5. 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.

  6. Optimization and planning of emergency evacuation routes considering traffic control.

    PubMed

    Li, Guo; Zhang, Lijun; Wang, Zhaohua

    2014-01-01

    Emergencies, especially major ones, happen fast, randomly, as well as unpredictably, and generally will bring great harm to people's life and the economy. Therefore, governments and lots of professionals devote themselves to taking effective measures and providing optimal evacuation plans. This paper establishes two different emergency evacuation models on the basis of the maximum flow model (MFM) and the minimum-cost maximum flow model (MC-MFM), and proposes corresponding algorithms for the evacuation from one source node to one designated destination (one-to-one evacuation). Ulteriorly, we extend our evaluation model from one source node to many designated destinations (one-to-many evacuation). At last, we make case analysis of evacuation optimization and planning in Beijing, and obtain the desired evacuation routes and effective traffic control measures from the perspective of sufficiency and practicability. Both analytical and numerical results support that our models are feasible and practical.

  7. 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.

  8. Impact of road traffic emissions on ambient air quality in an industrialized area.

    PubMed

    Garcia, Sílvia M; Domingues, Gonçalo; Gomes, Carla; Silva, Alexandra V; Almeida, S Marta

    2013-01-01

    Several epidemiological studies showed a correlation between airborne particulate matter(PM) and the incidence of several diseases in exposed populations. Consequently, the European Commission reinforced the need and obligation of member-states to monitor exposure levels of PM and adopt measures to reduce this exposure. However, in order to plan appropriate actions, it is necessary to understand the main sources of air pollution and their relative contributions to the formation of the ambient aerosol. The aim of this study was to develop a methodology to assess the contribution of vehicles to the atmospheric aerosol,which may constitute a useful tool to assess the effectiveness of planned mitigation actions.This methodology is based on three main steps: (1) estimation of traffic emissions provided from the vehicles exhaust and resuspension; (2) use of the dispersion model TAPM (“The Air Pollution Model”) to estimate the contribution of traffic for the atmospheric aerosol; and(3) use of geographic information system (GIS) tools to map the PM10 concentrations provided from traffic in the surroundings of a target area. The methodology was applied to an industrial area, and results showed that the highest contribution of traffic for the PM10 concentrations resulted from dust resuspension and that heavy vehicles were the type that most contributed to the PM10 concentration.

  9. The Conception Approach to the Traffic Control in Czech Cities - Examples from Prague

    NASA Astrophysics Data System (ADS)

    Tichý, Tomáš; Krajčír, Dušan

    Modern and economic development of contemporary towns is without question highly dependent upon traffic infrastructure progress. Automobile transport intensity is dramatically rising in large towns and other Czech and European cities. At the same time number of traffic congestions and accidents is increasing, standing times are becoming longer and ecological stress is also escalated. To solve this situation seems to be the most effective solution to design intelligent traffic light intersection control system, variable message signs, preference of public transportation, road line traffic control and next telematics subsystems. This control system and subsystems should improve permeability of traffic road network with a respect for all demands on recent trends of traffic development in towns and regions.

  10. Real-time calibration of platoon dispersion model to optimize the coordinated traffic signal timing in ATMS networks

    SciTech Connect

    Yu, L.

    1999-06-01

    Vehicles form platoons at the exit point of a given traffic signal, which will disperse while they progress along the link towards the next downstream traffic signal. The platoons may disperse either more quickly or slowly depending on the actual road geometric and traffic conditions between the two adjacent intersections of interest. The adequate modeling and description of the platoon dispersion behavior ultimately affect the quality of the coordinated traffic signal timings. At present, the most widely used modeling method of platoon dispersion is the TRANSYT`s macroscopic platoon dispersion model in which the determination of its major parameters is based on the empirical values. This report presents a methodology for calibrating the platoon dispersion parameters in the TRANSYT`s platoon dispersion model, which is based on a statistical analysis of link travel time data rather than more traditional goodness-of-fit tests between the observed and the projected vehicles` progression patterns.

  11. Marine Air Traffic Control and Landing System (METCALS) Investigation.

    DTIC Science & Technology

    1982-02-01

    worked as designed, but exhibited drift characteristics which would adversely affect aircraft tracking accuracy. The most promising signal amplitude...Georgia Institute of Technology AREA & WORK UNIT NUMBERS Engineering Experiment Station Radar and Instrumentation Laboratory Atlanta. Gpnrgia 30332 II...RBS systems. Statistical Tracking Error Model Only a very limited amount of work was accomplished on the statistical tracking error task before

  12. Field Scale Spatial Modelling of Surface Soil Quality Attributes in Controlled Traffic Farming

    NASA Astrophysics Data System (ADS)

    Guenette, Kris; Hernandez-Ramirez, Guillermo

    2017-04-01

    The employment of controlled traffic farming (CTF) can yield improvements to soil quality attributes through the confinement of equipment traffic to tramlines with the field. There is a need to quantify and explain the spatial heterogeneity of soil quality attributes affected by CTF to further improve our understanding and modelling ability of field scale soil dynamics. Soil properties such as available nitrogen (AN), pH, soil total nitrogen (STN), soil organic carbon (SOC), bulk density, macroporosity, soil quality S-Index, plant available water capacity (PAWC) and unsaturated hydraulic conductivity (Km) were analysed and compared among trafficked and un-trafficked areas. We contrasted standard geostatistical methods such as ordinary kriging (OK) and covariate kriging (COK) as well as the hybrid method of regression kriging (ROK) to predict the spatial distribution of soil properties across two annual cropland sites actively employing CTF in Alberta, Canada. Field scale variability was quantified more accurately through the inclusion of covariates; however, the use of ROK was shown to improve model accuracy despite the regression model composition limiting the robustness of the ROK method. The exclusion of traffic from the un-trafficked areas displayed significant improvements to bulk density, macroporosity and Km while subsequently enhancing AN, STN and SOC. The ability of the regression models and the ROK method to account for spatial trends led to the highest goodness-of-fit and lowest error achieved for the soil physical properties, as the rigid traffic regime of CTF altered their spatial distribution at the field scale. Conversely, the COK method produced the most optimal predictions for the soil nutrient properties and Km. The use of terrain covariates derived from light ranging and detection (LiDAR), such as of elevation and topographic position index (TPI), yielded the best models in the COK method at the field scale.

  13. 14 CFR Special Federal Aviation... - Air Traffic Control System Emergency Operation

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Control System Emergency Operation 1. Each person shall, before conducting any operation under the Federal..., prohibition, procedure or other action taken by the Director of the Office of Air Traffic Systems Management... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Air Traffic Control System...

  14. Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

    ERIC Educational Resources Information Center

    Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

    2010-01-01

    In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

  15. Dimensions of Air Traffic Control Tower Information Needs: From Information Requests to Display Design

    ERIC Educational Resources Information Center

    Durso, Francis T.; Johnson, Brian R.; Crutchfield, Jerry M.

    2010-01-01

    In an effort to determine the information needs of tower air traffic controllers, instructors from the Federal Aviation Administration's Academy in Oklahoma City were asked to control traffic in a high-fidelity tower cab simulator. Information requests were made apparent by eliminating access to standard tower information sources. Instead,…

  16. Traffic represents the main source of pollution in small Mediterranean urban areas as seen by lichen functional groups.

    PubMed

    Llop, Esteve; Pinho, Pedro; Ribeiro, Manuel C; Pereira, Maria João; Branquinho, Cristina

    2017-05-01

    The land-use type (residential, green areas, and traffic) within relatively small Mediterranean urban areas determines significant changes on lichen diversity, considering species richness and functional groups related to different ecological factors. Those areas with larger volume of traffic hold lower species diversity, in terms of species richness and lichen diversity value (LDV). Traffic areas also affect the composition of the lichen community, which is evidenced by sensitive species. The abundance of species of lichens tolerant to low levels of eutrophication diminishes in traffic areas; oppositely, those areas show a higher abundance of species of lichens tolerating high levels of eutrophication. On the other hand, residential and green areas have an opposite pattern, mainly with species highly tolerant to eutrophication being less abundant than low or moderate ones. The characteristics of tree bark do not seem to affect excessively on lichen composition; however, tree species shows some effect that should be considered in further studies.

  17. Do the pollution related to high-traffic roads in urbanised areas pose a significant threat to the local population?

    PubMed

    Kobza, Joanna; Geremek, Mariusz

    2017-01-01

    Many large neighbourhoods are located near heavy-traffic roads; therefore, it is necessary to control the levels of air pollution near road exposure. The primary air pollutants emitted by motor vehicles are CO, NO2 and PM. Various investigations identify key health outcomes to be consistently associated with NO2 and CO. The objective of this study was the measurement-based assessment for determining whether by high-traffic roads, such as motorways and express ways, and the concentrations of CO and NO2 are within normal limits and do not pose threat to the local population. Average daily values (arithmetic values calculated for 1-h values within 24 h or less, depending on result availability) were measured for concentrations of NO2 and CO by automatic stations belonging to the Voivodship Environmental Protection Inspectorate in Katowice, in areas with similar dominant source of pollutant emission. The measurements were made in three sites: near the motorway and expressway, where the average daily traffic intensity is 100983 and 35414 of vehicles relatively. No evidence was found of exceeding average daily values equal to the maximum allowable NO2 concentration due to the protection of human health in the measurement area of the stations. No daily average values exceeding the admissible CO concentration (8-h moving average) were noted in the examined period. The results clearly show lack of hazards for general population health in terms of increased concentrations of CO and NO2 compounds that are closely related to high intensity car traffic found on selected motorways and speedways located near the city centres.

  18. Effects of traffic noise on tree frog stress levels, immunity, and color signaling.

    PubMed

    Troïanowski, Mathieu; Mondy, Nathalie; Dumet, Adeline; Arcanjo, Caroline; Lengagne, Thierry

    2017-10-01

    During the last decade, many studies have focused on the detrimental effects of noise pollution on acoustic communication. Surprisingly, although it is known that noise exposure strongly influences health in humans, studies on wildlife remain scarce. In order to gain insight into the consequences of traffic noise exposure, we experimentally manipulated traffic noise exposure as well as the endocrine status of animals to investigate physiological and phenotypic consequences of noise pollution in an anuran species. We showed that noise exposure increased stress hormone level and induced an immunosuppressive effect. In addition, both traffic noise exposure and stress hormone application negatively impacted H. arborea vocal sac coloration. Moreover, our results suggest profound changes in sexual selection processes because the best quality males with initial attractive vocal sac coloration were the most impacted by noise. Hence, our study suggests that the recent increases in anthropogenic noise worldwide might affect a broader range of animal species than previously thought, because of alteration of visual signals and immunity. Generalizing these results to other taxa is crucial for the conservation of biodiversity in an increasingly noisy world. © 2017 Society for Conservation Biology.

  19. The Traffic Noise Index: A Method of Controlling Noise Nuisance.

    ERIC Educational Resources Information Center

    Langdon, F. J.; Scholes, W. E.

    This building research survey is an analysis of the social nuisance caused by urban motor ways and their noise. The Traffic Noise Index is used to indicate traffic noises and their effects on architectural designs and planning, while suggesting the need for more and better window insulation and acoustical barriers. Overall concern is for--(1)…

  20. 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...

  1. A junction-tree based learning algorithm to optimize network wide traffic control: A coordinated multi-agent framework

    SciTech Connect

    Zhu, Feng; Aziz, H. M. Abdul; Qian, Xinwu; Ukkusuri, Satish V.

    2015-01-31

    Our study develops a novel reinforcement learning algorithm for the challenging coordinated signal control problem. Traffic signals are modeled as intelligent agents interacting with the stochastic traffic environment. The model is built on the framework of coordinated reinforcement learning. The Junction Tree Algorithm (JTA) based reinforcement learning is proposed to obtain an exact inference of the best joint actions for all the coordinated intersections. Moreover, the algorithm is implemented and tested with a network containing 18 signalized intersections in VISSIM. Finally, our results show that the JTA based algorithm outperforms independent learning (Q-learning), real-time adaptive learning, and fixed timing plans in terms of average delay, number of stops, and vehicular emissions at the network level.

  2. A junction-tree based learning algorithm to optimize network wide traffic control: A coordinated multi-agent framework

    DOE PAGES

    Zhu, Feng; Aziz, H. M. Abdul; Qian, Xinwu; ...

    2015-01-31

    Our study develops a novel reinforcement learning algorithm for the challenging coordinated signal control problem. Traffic signals are modeled as intelligent agents interacting with the stochastic traffic environment. The model is built on the framework of coordinated reinforcement learning. The Junction Tree Algorithm (JTA) based reinforcement learning is proposed to obtain an exact inference of the best joint actions for all the coordinated intersections. Moreover, the algorithm is implemented and tested with a network containing 18 signalized intersections in VISSIM. Finally, our results show that the JTA based algorithm outperforms independent learning (Q-learning), real-time adaptive learning, and fixed timing plansmore » in terms of average delay, number of stops, and vehicular emissions at the network level.« less

  3. Traffic-related air pollution and sleep in the Boston Area Community Health Survey.

    PubMed

    Fang, Shona C; Schwartz, Joel; Yang, May; Yaggi, H Klar; Bliwise, Donald L; Araujo, Andre B

    2015-01-01

    Little is known about environmental determinants of sleep. We investigated the association between black carbon (BC), a marker of traffic-related air pollution, and sleep measures among participants of the Boston Area Community Health Survey. We also sought to assess the impact of sociodemographic factors, health conditions, and season on associations. Residential 24-h BC was estimated from a validated land-use regression model for 3821 participants and averaged over 1-6 months and 1 year. Sleep measures included questionnaire-assessed sleep duration, sleep latency, and sleep apnea. Linear and logistic regression models controlling for confounders estimated the association between sleep measures and BC. Effect modification was tested with interaction terms. Main effects were not observed between BC and sleep measures. However, in stratified models, males experienced 0.23 h less sleep (95% CI: -0.42, -0.03) and those with low SES 0.25 h less sleep (95% CI: -0.48, -0.01) per IQR increase in annual BC (0.21 μg/m(3)). In blacks, sleep duration increased with annual BC (β=0.34 per IQR; 95% CI: 0.12, 0.57). Similar findings were observed for short sleep (≤5 h). BC was not associated with sleep apnea or sleep latency, however, long-term exposure may be associated with shorter sleep duration, particularly in men and those with low SES, and longer sleep duration in blacks.

  4. 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

  5. Method and system for an automated tool for en route traffic controllers

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz (Inventor); McNally, B. David (Inventor)

    2001-01-01

    A method and system for a new automation tool for en route air traffic controllers first finds all aircraft flying on inefficient routes, then determines whether it is possible to save time by bypassing some route segments, and finally whether the improved route is free of conflicts with other aircraft. The method displays all direct-to eligible aircraft to an air traffic controller in a list sorted by highest time savings. By allowing the air traffic controller to easily identify and work with the highest pay-off aircraft, the method of the present invention contributes to a significant increase in both air traffic controller and aircraft productivity. A graphical computer interface (GUI) is used to enable the air traffic controller to send the aircraft direct to a waypoint or fix closer to the destination airport by a simple point and click action.

  6. Method and System For an Automated Tool for En Route Traffic Controllers

    NASA Technical Reports Server (NTRS)

    Erzberger, Heinz (Inventor); McNally, B. David (Inventor)

    2001-01-01

    A method and system for a new automation tool for en route air traffic controllers first finds all aircraft flying on inefficient routes, then determines whether it is possible to save time by bypassing some route segments, and finally whether the improved route is free of conflicts with other aircraft. The method displays all direct-to eligible aircraft to an air traffic controller in a list sorted by highest time savings. By allowing the air traffic controller to easily identify and work with the highest pay-off aircraft, the method of the present invention contributes to a significant increase in both air traffic controller and aircraft productivity. A graphical computer interface (GUI) is used to enable the air traffic controller to send the aircraft direct to a waypoint or fix closer to the destination airport by a simple point and click action.

  7. Cognitive process modelling of controllers in en route air traffic control.

    PubMed

    Inoue, Satoru; Furuta, Kazuo; Nakata, Keiichi; Kanno, Taro; Aoyama, Hisae; Brown, Mark

    2012-01-01

    In recent years, various efforts have been made in air traffic control (ATC) to maintain traffic safety and efficiency in the face of increasing air traffic demands. ATC is a complex process that depends to a large degree on human capabilities, and so understanding how controllers carry out their tasks is an important issue in the design and development of ATC systems. In particular, the human factor is considered to be a serious problem in ATC safety and has been identified as a causal factor in both major and minor incidents. There is, therefore, a need to analyse the mechanisms by which errors occur due to complex factors and to develop systems that can deal with these errors. From the cognitive process perspective, it is essential that system developers have an understanding of the more complex working processes that involve the cooperative work of multiple controllers. Distributed cognition is a methodological framework for analysing cognitive processes that span multiple actors mediated by technology. In this research, we attempt to analyse and model interactions that take place in en route ATC systems based on distributed cognition. We examine the functional problems in an ATC system from a human factors perspective, and conclude by identifying certain measures by which to address these problems. This research focuses on the analysis of air traffic controllers' tasks for en route ATC and modelling controllers' cognitive processes. This research focuses on an experimental study to gain a better understanding of controllers' cognitive processes in air traffic control. We conducted ethnographic observations and then analysed the data to develop a model of controllers' cognitive process. This analysis revealed that strategic routines are applicable to decision making.

  8. Pattern of traffic injuries in Shanghai: implications for control.

    PubMed

    Yan-Hong, Li; Rahim, Yousif; Wei, Lu; Gui-Xiang, Song; Yan, Yu; De Ding, Zhou; Sheng-Nian, Zhang; Shun-Fu, Zhou; Shao-Ming, Chen; Bing-Jie, Yang

    2006-12-01

    In China, traffic-related injuries are often treated as transportation issues, called 'accidents'. The objectives of the research are to analyse traffic injury patterns, estimate costs of traffic injuries and provide evidence to develop effective prevention strategies. There were over 1 500 deaths due to traffic-related injuries annually in Shanghai from 1987 to 2003, and it is rising year by year with the rate of growth in motorization. The rates of annual increase are 3.59% in fatalities (from 7.78 to 14.18 per 100000 population) and 10.46% in non-fatalities (from 53.93 to 264.98 per 100000 population) respectively during the period. The analysis of the geographic information system showed that the geographic distribution of traffic injuries in the countryside regions of Shanghai had the highest rates. Labour force groups represented the majority of fatalities (70.97%) and serious traffic injuries (90.51%). The mortality rates were 18.40 per 100000 population and 10.02 per 100000 population in 45-65 year age group and 15-44 year age group respectively; the morbidity rates of serious traffic injuries were 121.60 per 100000 population and 70.46 per 100000 population in the same groups respectively. And females generally showed a lower incidence than males. In general, fatalities and injuries were higher for drivers, bicyclists and pedestrians. Among road traffic injury-related fatalities, 66.8% were attributed to head injuries. Of those with fatal head injuries, bicyclists accounted for 29.8% of the total; pedestrians accounted for 28.3%; motorcyclists accounted for 25.5%. Total traffic injury cost was estimated at least US $645989580 in Shanghai in 2003. Good injury intervention programmes need to be done as soon as possible to effectively reduce traffic injury burden in Shanghai, China.

  9. 33 CFR 167.350 - In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas. 167.350 Section 167.350 Navigation and... Atlantic Gulf Coast § 167.350 In the approaches to Galveston Bay Traffic Separation Scheme and...

  10. 33 CFR 167.350 - In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas. 167.350 Section 167.350 Navigation and... Atlantic Gulf Coast § 167.350 In the approaches to Galveston Bay Traffic Separation Scheme and...

  11. 33 CFR 167.350 - In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false In the approaches to Galveston Bay Traffic Separation Scheme and precautionary areas. 167.350 Section 167.350 Navigation and... Atlantic Gulf Coast § 167.350 In the approaches to Galveston Bay Traffic Separation Scheme and...

  12. Gaseous ammonia in the urban area of Rome, Italy and its relationship with traffic emissions

    NASA Astrophysics Data System (ADS)

    Perrino, C.; Catrambone, M.; Di Menno Di Bucchianico, A.; Allegrini, I.

    The atmospheric concentration of gaseous ammonia has been measured during selected field campaigns from the spring of 2001 to the spring of 2002 in the urban area of Rome, at many traffic sites and at an urban background site. The concentration level at the traffic sites was in all cases about five times the background level and always much higher than the concentration in a rural near-city area. The time trend of ammonia is well correlated with the trend of a primary low-reactivity pollutant such as carbon monoxide. The concentration values of both pollutants depend on the intensity of traffic emission and on the atmospheric mixing in the boundary layer. Ammonia concentration is also dependent on the air temperature. A close link between NH 3 and CO air values has been confirmed at all the measurement stations of the Air Quality Network of Rome. These results indicate that the emissions from petrol-engine vehicles equipped with catalytic converters can be an important source of ammonia in urban areas. The implications of these findings for the chemistry of the urban atmosphere need to be carefully considered.

  13. Controlled traffic conservation tillage using small to middle sized machinery in China

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoyan; Li, Hongwen; Gao, Huanwen; Du, Bing; He, Jin; Li, Wenying

    2005-09-01

    Research and farmers' experiences have demonstrated that reduced tillage helps maintain surface residues and provide substantial benefits in terms of water use efficiency, soil condition and productivity. However, the impact of field traffic and its influence on the soil when tillage is reduced or eliminated have been ignored, for small to middle-sized machinery are mostly used in Chinese agriculture. There is a need to study on wheel traffic impacts and to test controlled traffic farming system for Chinese conditions. This paper reports the five-year controlled traffic conservation tillage experiment in North China. Two trial plots (Spring Maize and Winter wheat) with four treatments and five replications were set up. The results indicated that controlled traffic conservation tillage could minimize the compaction of wheel traffic, make field operation timely and precisely, improve soil structure and increase soil moisture on crop zone which is beneficial to crop establishment and growth. With the accumulation of damages year after year, the impacts of random wheeling are becoming more notable. Heavier machinery appeared to compact soil to a greater depth, but even small tractors could compact the surface 10cm, critical to rainfall infiltration, to a remarkable degree. For the small-scaled controlled traffic system tested in this study, traffic lanes occupy about 20% of the land, but the yields were similar to those in the non-controlled traffic fields. Further test is needed for the long-term impacts of the traffic lanes on soil structure and crop yield and detailed analysis is necessary to develop a suitable controlled traffic farming system.

  14. Control of epidemic spreading on complex networks by local traffic dynamics

    NASA Astrophysics Data System (ADS)

    Yang, Han-Xin; Wang, Wen-Xu; Lai, Ying-Cheng; Xie, Yan-Bo; Wang, Bing-Hong

    2011-10-01

    Despite extensive work on traffic dynamics and epidemic spreading on complex networks, the interplay between these two types of dynamical processes has not received adequate attention. We study the effect of local-routing-based traffic dynamics on epidemic spreading. For the case of unbounded node-delivery capacity, where the traffic is free of congestion, we obtain analytic and numerical results indicating that the epidemic threshold can be maximized by an optimal routing protocol. This means that epidemic spreading can be effectively controlled by local traffic dynamics. For the case of bounded delivery capacity, numerical results and qualitative arguments suggest that traffic congestion can suppress epidemic spreading. Our results provide quantitative insight into the nontrivial role of traffic dynamics associated with a local-routing scheme in the epidemic spreading.

  15. Control of epidemic spreading on complex networks by local traffic dynamics.

    PubMed

    Yang, Han-Xin; Wang, Wen-Xu; Lai, Ying-Cheng; Xie, Yan-Bo; Wang, Bing-Hong

    2011-10-01

    Despite extensive work on traffic dynamics and epidemic spreading on complex networks, the interplay between these two types of dynamical processes has not received adequate attention. We study the effect of local-routing-based traffic dynamics on epidemic spreading. For the case of unbounded node-delivery capacity, where the traffic is free of congestion, we obtain analytic and numerical results indicating that the epidemic threshold can be maximized by an optimal routing protocol. This means that epidemic spreading can be effectively controlled by local traffic dynamics. For the case of bounded delivery capacity, numerical results and qualitative arguments suggest that traffic congestion can suppress epidemic spreading. Our results provide quantitative insight into the nontrivial role of traffic dynamics associated with a local-routing scheme in the epidemic spreading.

  16. Human factors in aviation: Terminal control area boundary conflicts

    NASA Technical Reports Server (NTRS)

    Monan, William P.

    1989-01-01

    Air-to-air conflicts in the vicinity of Terminal Control Area (TCA) boundaries were studied to obtain a better understanding of the causal dynamics of these events with particular focus on human factor issues. The study dataset consisted of 381 Instrument Flight Rules/Visual Flight Rules (IFR/VFR) traffic conflicts in airspace layers above TCA ceiling and below TCA floors; 213 reports of incursions in TCA terminal airspace by VFR aircraft, of which 123 resulted in conflicts; and an additional set of reports describing problems with Air Traffic Control (ATC) services in and around TCAs. Results and conclusions are detailed.

  17. TASAR Flight Trial 2: Assessment of Air Traffic Controller Acceptability of TASAR Requests

    NASA Technical Reports Server (NTRS)

    Idris, Husni; Enea, Gabriele

    2016-01-01

    In support of the Flight Trial (FT-2) of NASA's prototype of the Traffic Aware Strategic Aircrew Requests (TASAR) concept, observations were conducted at the air traffic facilities to identify and assess the main factors that affect the acceptability of pilot requests by air traffic controllers. Two observers shadowed air traffic controllers at the Atlanta (ZTL) and Jacksonville (ZJX) air traffic control centers as the test flight pilot made pre-scripted requests to invoke acceptability issues and then they interviewed the observed and other controllers voluntarily. Fifty controllers were interviewed with experience ranging from one to thirty-five years. All interviewed controllers were enthusiastic about the technology and accounting for sector boundaries in pilot requests, particularly if pilots can be made aware of high workload situations. All interviewed controllers accept more than fifty percent of pilot requests; forty percent of them reject less than ten percent of requests. The most common reason for rejecting requests is conflicting with traffic followed by violating letters of agreement (LOAs) and negatively impacting neighboring sector workload, major arrival and departure flows and flow restrictions. Thirty-six requests were made during the test, eight of which were rejected due to: the aircraft already handed off to another sector, violating LOA, opposing traffic, intruding into an active special use airspace (SUA), intruding into another center, weather, and unfamiliarity with the requested waypoint. Nine requests were accepted with delay mostly because the controller needed to locate unfamiliar waypoints or to coordinate with other controllers.

  18. Mass casualty tracking with air traffic control methodologies.

    PubMed

    Hoskins, Jason D; Graham, Ross F; Robinson, Duane R; Lutz, Clifford C; Folio, Les R

    2009-06-01

    An intrahospital casualty throughput system modeled after air traffic control (ATC) tracking procedures was tested in mass casualty exercises. ATC uses a simple tactile process involving informational progress strips representing each aircraft, which are held in bays representing each stage of flight to prioritize and manage aircraft. These strips can be reordered within the bays to indicate a change in priority of aircraft sequence. In this study, a similar system was designed for patient tracking. We compared the ATC model and traditional casualty tracking methods of paper and clipboard in 18 four-hour casualty scenarios, each with 5 to 30 mock casualties. The experimental and control groups were alternated to maximize exposure and minimize training effects. Results were analyzed with Mann-Whitney statistical analysis with p value < 0.05 (two-sided). The ATC method had significantly (p = 0.017) fewer errors in critical patient data (eg, name, social security number, diagnosis). Specifically, the ATC method better tracked the mechanism of injury, working diagnosis, and disposition of patients. The ATC method also performed considerably better with patient accountability during mass casualty scenarios. Data strips were comparable with the control method in terms of ease of use. In addition, participants preferred the ATC method to the control (p = 0.003) and preferred using the ATC method (p = 0.003) to traditional methods in the future. The ATC model more effectively tracked patient data with fewer errors when compared with the clipboard method. Application of these principles can enhance trauma management and can have application in civilian and military trauma centers and emergency rooms.

  19. Feedback control scheme of traffic jams based on the coupled map car-following model

    NASA Astrophysics Data System (ADS)

    Zhou, Tong; Sun, Di-Hua; Zhao, Min; Li, Hua-Min

    2013-09-01

    Based on the pioneering work of Konishi et al. [Phys. Rev. E (1999) 60 4000], a new feedback control scheme is presented to suppress traffic jams based on the coupled map car-following model under the open boundary condition. The effect of the safe headway on the traffic system is considered. According to the control theory, the condition under which traffic jams can be suppressed is analyzed. The results are compared with the previous results concerning congestion control. The simulations show that the suppression performance of our scheme on traffic jams is better than those of the previous schemes, although all the schemes can suppress traffic jams. The simulation results are consistent with theoretical analyses.

  20. To Cross or Not to Cross: Objective Timing Methods of Assessing Street Crossings without Traffic Controls.

    ERIC Educational Resources Information Center

    Sauerburger, Dona

    1989-01-01

    This paper presents methods for visually impaired pedestrians assessing safety of street crossings in the absence of traffic controls, considering both limited detection ability and the difficulty of judging when approaching traffic is distant or slow enough to allow crossing. Alternatives for "uncrossable" streets and teaching methods are…

  1. Evaluation of the Capacity and Delay Benefits of Terminal Air Traffic Control Automation

    DTIC Science & Technology

    1993-04-14

    in arrival capacity. The report includes a detailed analysis of high-density IMC arrival traffic at Boston Logan airport. The factors that affect...Air Traffic Control ..................... 24 3.2.1 Presentation of Field Data. Single Arrival Runway, IMC, at Boston Logan Airport...Research ................................... 46 Table 15 Observed IMC Arrival Sequencing at Boston Logan .................. 52 Table 16 Summary of

  2. Time-based self-spacing techniques using cockpit display of traffic information during approach to landing in a terminal area vectoring environment

    NASA Technical Reports Server (NTRS)

    Williams, D. H.

    1983-01-01

    A simulation study was undertaken to evaluate two time-based self-spacing techniques for in-trail following during terminal area approach. An electronic traffic display was provided in the weather radarscope location. The displayed self-spacing cues allowed the simulated aircraft to follow and to maintain spacing on another aircraft which was being vectored by air traffic control (ATC) for landing in a high-density terminal area. Separation performance data indicate the information provided on the traffic display was adequate for the test subjects to accurately follow the approach path of another aircraft without the assistance of ATC. The time-based technique with a constant-delay spacing criterion produced the most satisfactory spacing performance. Pilot comments indicate the workload associated with the self-separation task was very high and that additional spacing command information and/or aircraft autopilot functions would be desirable for operational implementational of the self-spacing task.

  3. Effects of iterative learning based signal control strategies on macroscopic fundamental diagrams of urban road networks

    NASA Astrophysics Data System (ADS)

    Yan, Fei; Tian, Fuli; Shi, Zhongke

    2016-10-01

    Urban traffic flows are inherently repeated on a daily or weekly basis. This repeatability can help improve the traffic conditions if it is used properly by the control system. In this paper, we propose a novel iterative learning control (ILC) strategy for traffic signals of urban road networks using the repeatability feature of traffic flow. To improve the control robustness, the ILC strategy is further integrated with an error feedback control law in a complementary manner. Theoretical analysis indicates that the ILC-based traffic signal control methods can guarantee the asymptotic learning convergence, despite the presence of modeling uncertainties and exogenous disturbances. Finally, the impacts of the ILC-based signal control strategies on the network macroscopic fundamental diagram (MFD) are examined. The results show that the proposed ILC-based control strategies can homogenously distribute the network accumulation by controlling the vehicle numbers in each link to the desired levels under different traffic demands, which can result in the network with high capacity and mobility.

  4. Color Analysis in Air Traffic Control Displays. Part 1: Radar Displays

    DTIC Science & Technology

    2006-10-01

    controllers use several displays at their workstation. This report includes displays used at two types of air traffic facilities: the en route air...traffic control center, referenced as en route facilities, and the terminal radar approach control, referenced as TRACON facili- ties. Typically, a...decision-making. For example, operational controllers at some en route facilities use Display System Replace- ment (DSR) as the primary display; they

  5. Quantification of the impact of aircraft traffic emissions on tropospheric ozone over Paris area

    NASA Astrophysics Data System (ADS)

    Pison, Isabelle; Menut, Laurent

    Accurate estimations of the emissions of primary pollutants are crucial for the modeling of photo-oxidants' concentrations. For a majority of chemistry-transport models (CTMs), these emissions are taken into account near the surface only. They are expressed as surface fluxes and represent surface activities such as traffic, industries or biogenic processes. However, in the vicinity of large cities, commercial aircraft emissions represent a nonnegligible source, located both at the surface and at altitude, including landing and take-off of aircraft within the boundary layer. This is the case of Paris where one national airport (Le Bourget) and two international airports (Roissy-Charles-de-Gaulle and Orly) are located less than 30 km away from the city center. This study presents the first-model analysis of the impact of aircraft emissions on photo-oxidant concentrations over the Paris area. Using a three-dimensional aircraft emission inventory, we compare ozone surface concentrations obtained with and without these emissions by running the CTM CHIMERE during the second Intensive Observation Period of the ESQUIF project. The simulated differences enable us to estimate the impact of aircraft traffic emissions on ozone surface concentrations in and around the city. The results showed that the maximum impact, which consists in a fast ozone titration by NO near the airports within the surface layer, occurs during the night. In remote areas and at altitude, adding new emissions enhanced photo-chemistry during the afternoon. In order to estimate the impact of the uncertainty of our inventory, aircraft emitted masses of volatile organic compounds (VOCs) and NO x are perturbed. The results showed that NO x air traffic emissions have a more important impact than VOC emissions, particularly during the night and near the sources. Nevertheless, these variations of air traffic emissions do not change previous conclusions.

  6. Microwave landing system modeling with application to air traffic control

    NASA Technical Reports Server (NTRS)

    Poulose, M. M.

    1991-01-01

    Compared to the current instrument landing system, the microwave landing system (MLS), which is in the advanced stage of implementation, can potentially provide significant fuel and time savings as well as more flexibility in approach and landing functions. However, the expanded coverage and increased accuracy requirements of the MLS make it more susceptible to the features of the site in which it is located. An analytical approach is presented for evaluating the multipath effects of scatterers that are commonly found in airport environments. The approach combines a multiplane model with a ray-tracing technique and a formulation for estimating the electromagnetic fields caused by the antenna array in the presence of scatterers. The model is applied to several airport scenarios. The reduced computational burden enables the scattering effects on MLS position information to be evaluated in near real time. Evaluation in near real time would permit the incorporation of the modeling scheme into air traffic control automation; it would adaptively delineate zones of reduced accuracy within the MLS coverage volume, and help establish safe approach and takeoff trajectories in the presence of uneven terrain and other scatterers.

  7. Characterization of Visual Scanning Patterns in Air Traffic Control.

    PubMed

    McClung, Sarah N; Kang, Ziho

    2016-01-01

    Characterization of air traffic controllers' (ATCs') visual scanning strategies is a challenging issue due to the dynamic movement of multiple aircraft and increasing complexity of scanpaths (order of eye fixations and saccades) over time. Additionally, terminologies and methods are lacking to accurately characterize the eye tracking data into simplified visual scanning strategies linguistically expressed by ATCs. As an intermediate step to automate the characterization classification process, we (1) defined and developed new concepts to systematically filter complex visual scanpaths into simpler and more manageable forms and (2) developed procedures to map visual scanpaths with linguistic inputs to reduce the human judgement bias during interrater agreement. The developed concepts and procedures were applied to investigating the visual scanpaths of expert ATCs using scenarios with different aircraft congestion levels. Furthermore, oculomotor trends were analyzed to identify the influence of aircraft congestion on scan time and number of comparisons among aircraft. The findings show that (1) the scanpaths filtered at the highest intensity led to more consistent mapping with the ATCs' linguistic inputs, (2) the pattern classification occurrences differed between scenarios, and (3) increasing aircraft congestion caused increased scan times and aircraft pairwise comparisons. The results provide a foundation for better characterizing complex scanpaths in a dynamic task and automating the analysis process.

  8. Characterization of Visual Scanning Patterns in Air Traffic Control

    PubMed Central

    McClung, Sarah N.; Kang, Ziho

    2016-01-01

    Characterization of air traffic controllers' (ATCs') visual scanning strategies is a challenging issue due to the dynamic movement of multiple aircraft and increasing complexity of scanpaths (order of eye fixations and saccades) over time. Additionally, terminologies and methods are lacking to accurately characterize the eye tracking data into simplified visual scanning strategies linguistically expressed by ATCs. As an intermediate step to automate the characterization classification process, we (1) defined and developed new concepts to systematically filter complex visual scanpaths into simpler and more manageable forms and (2) developed procedures to map visual scanpaths with linguistic inputs to reduce the human judgement bias during interrater agreement. The developed concepts and procedures were applied to investigating the visual scanpaths of expert ATCs using scenarios with different aircraft congestion levels. Furthermore, oculomotor trends were analyzed to identify the influence of aircraft congestion on scan time and number of comparisons among aircraft. The findings show that (1) the scanpaths filtered at the highest intensity led to more consistent mapping with the ATCs' linguistic inputs, (2) the pattern classification occurrences differed between scenarios, and (3) increasing aircraft congestion caused increased scan times and aircraft pairwise comparisons. The results provide a foundation for better characterizing complex scanpaths in a dynamic task and automating the analysis process. PMID:27239190

  9. An error-resistant linguistic protocol for air traffic control

    NASA Technical Reports Server (NTRS)

    Cushing, Steven

    1989-01-01

    The research results described here are intended to enhance the effectiveness of the DATALINK interface that is scheduled by the Federal Aviation Administration (FAA) to be deployed during the 1990's to improve the safety of various aspects of aviation. While voice has a natural appeal as the preferred means of communication both among humans themselves and between humans and machines as the form of communication that people find most convenient, the complexity and flexibility of natural language are problematic, because of the confusions and misunderstandings that can arise as a result of ambiguity, unclear reference, intonation peculiarities, implicit inference, and presupposition. The DATALINK interface will avoid many of these problems by replacing voice with vision and speech with written instructions. This report describes results achieved to date on an on-going research effort to refine the protocol of the DATALINK system so as to avoid many of the linguistic problems that still remain in the visual mode. In particular, a working prototype DATALINK simulator system has been developed consisting of an unambiguous, context-free grammar and parser, based on the current air-traffic-control language and incorporated into a visual display involving simulated touch-screen buttons and three levels of menu screens. The system is written in the C programming language and runs on the Macintosh II computer. After reviewing work already done on the project, new tasks for further development are described.

  10. Auction Mechanism to Allocate Air Traffic Control Slots

    NASA Technical Reports Server (NTRS)

    Raffarin, Marianne

    2003-01-01

    This article deals with an auction mechanism for airspace slots, as a means of solving the European airspace congestion problem. A disequilibrium, between Air Traffic Control (ATC) services supply and ATC services demand are at the origin of almost one fourth of delays in the air transport industry in Europe. In order to tackle this congestion problem, we suggest modifying both pricing and allocation of ATC services, by setting up an auction mechanism. Objects of the auction will be the right for airlines to cross a part of the airspace, and then to benefit from ATC services over a period corresponding to the necessary time for the crossing. Allocation and payment rules have to be defined according to the objectives of this auction. The auctioneer is the public authority in charge of ATC services, whose aim is to obtain an efficient allocation. Therefore, the social value will be maximized. Another objective is to internalize congestion costs. To that end, we apply the principle of Clarke-Groves mechanism auction: each winner has to pay the externalities imposed on other bidders. The complex context of ATC leads to a specific design for this auction.

  11. Signal transduction meets vesicle traffic: the software and hardware of GLUT4 translocation.

    PubMed

    Klip, Amira; Sun, Yi; Chiu, Tim Ting; Foley, Kevin P

    2014-05-15

    Skeletal muscle is the major tissue disposing of dietary glucose, a function regulated by insulin-elicited signals that impart mobilization of GLUT4 glucose transporters to the plasma membrane. This phenomenon, also central to adipocyte biology, has been the subject of intense and productive research for decades. We focus on muscle cell studies scrutinizing insulin signals and vesicle traffic in a spatiotemporal manner. Using the analogy of an integrated circuit to approach the intersection between signal transduction and vesicle mobilization, we identify signaling relays ("software") that engage structural/mechanical elements ("hardware") to enact the rapid mobilization and incorporation of GLUT4 into the cell surface. We emphasize how insulin signal transduction switches from tyrosine through lipid and serine phosphorylation down to activation of small G proteins of the Rab and Rho families, describe key negative regulation step of Rab GTPases through the GTPase-activating protein activity of the Akt substrate of 160 kDa (AS160), and focus on the mechanical effectors engaged by Rabs 8A and 10 (the molecular motor myosin Va), and the Rho GTPase Rac1 (actin filament branching and severing through Arp2/3 and cofilin). Finally, we illustrate how actin filaments interact with myosin 1c and α-Actinin4 to promote vesicle tethering as preamble to fusion with the membrane. Copyright © 2014 the American Physiological Society.

  12. The effectiveness of alcohol control policies on alcohol-related traffic fatalities in the United States.

    PubMed

    Chang, Koyin; Wu, Chin-Chih; Ying, Yung-Hsiang

    2012-03-01

    Multiple alcohol control policies have been enacted since the early 1980s to keep drunk drivers off the roads and to prevent more alcohol-related traffic fatalities. In this paper, we analyze nine traffic policies to determine the extent to which each policy contributes to effective alcohol-related fatality prevention. Compared with the existing literature, this paper addresses a more comprehensive set of traffic policies. In addition, we used a panel GLS model that holds regional effects and state-specific time effects constant to analyze their impact on alcohol-related fatalities with two distinct rates: alcohol-related traffic deaths per capita and alcohol-related traffic deaths per total traffic deaths. While per capita alcohol-related traffic deaths is used more often in other studies, alcohol-related traffic deaths per total traffic deaths better reflects the impact of policies on deterring drunk driving. In addition, regional analyses were conducted to determine the policies that are more effective in certain regions. The findings of this study suggest that zero tolerance laws and increased beer taxes are the most effective policies in reducing alcohol-related fatalities in all regions.

  13. System for area pollution control

    SciTech Connect

    Blikken, W.A.; Blikken, W.C.

    1991-12-03

    This paper describes a system for collecting and purifying polluted air in an urban geographic area subject to smog conditions and high volume automotive traffic at spaced intervals in a 24-hour day. It comprises: utilizing a plurality of open water draining which channels in an urban collection area, which channels are arranged in a flow pattern to carry rainfall water to a discharge area, installing covers over the open channels to enclose the open channels to provide an elongate air passage in the channels, providing side passages in the covers to admit drainage water into the channels and to meter polluted air into the channels in response to an induced sub-atmospheric pressure in the channels, providing a high volume of a jet engine of airplane capacity to create sub-atmospheric pressure ins aid channels and carry air in the channels to a converging area of the channels, and providing a depollution apparatus for the air prior to discharge at a site remote from the collection area in which the channels are located.

  14. Diabetes: Models, Signals and control

    NASA Astrophysics Data System (ADS)

    Cobelli, C.

    2010-07-01

    Diabetes and its complications impose significant economic consequences on individuals, families, health systems, and countries. The control of diabetes is an interdisciplinary endeavor, which includes significant components of modeling, signal processing and control. Models: first, I will discuss the minimal (coarse) models which describe the key components of the system functionality and are capable of measuring crucial processes of glucose metabolism and insulin control in health and diabetes; then, the maximal (fine-grain) models which include comprehensively all available knowledge about system functionality and are capable to simulate the glucose-insulin system in diabetes, thus making it possible to create simulation scenarios whereby cost effective experiments can be conducted in silico to assess the efficacy of various treatment strategies - in particular I will focus on the first in silico simulation model accepted by FDA as a substitute to animal trials in the quest for optimal diabetes control. Signals: I will review metabolic monitoring, with a particular emphasis on the new continuous glucose sensors, on the crucial role of models to enhance the interpretation of their time-series signals, and on the opportunities that they present for automation of diabetes control. Control: I will review control strategies that have been successfully employed in vivo or in silico, presenting a promise for the development of a future artificial pancreas and, in particular, I will discuss a modular architecture for building closed-loop control systems, including insulin delivery and patient safety supervision layers.

  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. Information Presentation and Control in a Modern Air Traffic Control Tower Simulator

    NASA Technical Reports Server (NTRS)

    Haines, Richard F.; Doubek, Sharon; Rabin, Boris; Harke, Stanton

    1996-01-01

    The proper presentation and management of information in America's largest and busiest (Level V) air traffic control towers calls for an in-depth understanding of many different human-computer considerations: user interface design for graphical, radar, and text; manual and automated data input hardware; information/display output technology; reconfigurable workstations; workload assessment; and many other related subjects. This paper discusses these subjects in the context of the Surface Development and Test Facility (SDTF) currently under construction at NASA's Ames Research Center, a full scale, multi-manned, air traffic control simulator which will provide the "look and feel" of an actual airport tower cab. Special emphasis will be given to the human-computer interfaces required for the different kinds of information displayed at the various controller and supervisory positions and to the computer-aided design (CAD) and other analytic, computer-based tools used to develop the facility.

  17. Algorithm and data support of traffic congestion forecasting in the controlled transport

    NASA Astrophysics Data System (ADS)

    Dmitriev, S. V.

    2015-06-01

    The topicality of problem of the traffic congestion forecasting in the logistic systems of product movement highways is considered. The concepts: the controlled territory, the highway occupancy by vehicles, the parking and the controlled territory are introduced. Technical realizabilityof organizing the necessary flow of information on the state of the transport system for its regulation has been marked. Sequence of practical implementation of the solution is given. An algorithm for predicting traffic congestion in the controlled transport system is suggested.

  18. An Experimental Study of the Noise Due to Traffic in a Congested Urban Area

    NASA Astrophysics Data System (ADS)

    Sangeetha, M.; Sankar, P.

    2016-03-01

    Noise pollution in an urban environment is an issue of serious concern in the major cities of India. There are various factors that contribute to the increase of noise levels in urban areas. The intensity of traffic is one of the factors which contributes to a drastic increase in environmental noise. The management of noise pollution has to be considered in the decision making process. In this paper, an attempt is made to study the existing noise level due to the traffic in Velachery which is declared as a sensitive area by the Ministry of Environment and Forestry (MoEF). The noise level data is collected using the MS6710 digital sound meter. The Custic simulation software version 3.2 is used for finding the propagation of noise. The spatial patterns of measurement were also calculated, in the sub-urban area of Velachery, Chennai, Tamilnadu, India. A means of transmitting this data to vehicles moving in the area, through a wireless medium is simulated using NCTUns 6.0 (network simulator), to enable drivers to understand the environmental conditions. A hardware was also designed which can be used to transmit and receive the noise data using the Zigbee module. A noise transmitting station is placed at a junction, so that it can transmit this noise data to the receivers which are fitted inside the vehicles.

  19. Pseudo Aircraft Systems - A multi-aircraft simulation system for air traffic control research

    NASA Technical Reports Server (NTRS)

    Weske, Reid A.; Danek, George L.

    1993-01-01

    Pseudo Aircraft Systems (PAS) is a computerized flight dynamics and piloting system designed to provide a high fidelity multi-aircraft real-time simulation environment to support Air Traffic Control research. PAS is composed of three major software components that run on a network of computer workstations. Functionality is distributed among these components to allow the system to execute fast enough to support real-time operation. PAS workstations are linked by an Ethernet Local Area Network, and standard UNIX socket protocol is used for data transfer. Each component of PAS is controlled and operated using a custom designed Graphical User Interface. Each of these is composed of multiple windows, and many of the windows and sub-windows are used in several of the components. Aircraft models and piloting logic are sophisticated and realistic and provide complex maneuvering and navigational capabilities. PAS will continually be enhanced with new features and improved capabilities to support ongoing and future Air Traffic Control system development.

  20. Pseudo Aircraft Systems - A multi-aircraft simulation system for air traffic control research

    NASA Technical Reports Server (NTRS)

    Weske, Reid A.; Danek, George L.

    1993-01-01

    Pseudo Aircraft Systems (PAS) is a computerized flight dynamics and piloting system designed to provide a high fidelity multi-aircraft real-time simulation environment to support Air Traffic Control research. PAS is composed of three major software components that run on a network of computer workstations. Functionality is distributed among these components to allow the system to execute fast enough to support real-time operation. PAS workstations are linked by an Ethernet Local Area Network, and standard UNIX socket protocol is used for data transfer. Each component of PAS is controlled and operated using a custom designed Graphical User Interface. Each of these is composed of multiple windows, and many of the windows and sub-windows are used in several of the components. Aircraft models and piloting logic are sophisticated and realistic and provide complex maneuvering and navigational capabilities. PAS will continually be enhanced with new features and improved capabilities to support ongoing and future Air Traffic Control system development.