Evaluation of the effects of school zone signs and markings on speed reduction: a driving simulator study.

PubMed

Zhao, Xiaohua; Li, Jiahui; Ma, Jianming; Rong, Jian

2016-01-01

Traffic control devices are one of the most significant factors affecting driving behavior. In China, there is a lack of installation guidelines or standards for traffic control devices in school zones. In addition, little research has been done to examine the effects of traffic control devices on driving behavior. Few guidelines have been established for implementing traffic control devices in school zones in China. This research conducted a driving simulator experiment to assess the effects of school zone signs and markings for two different types of schools. The efficiency of these traffic control devices was evaluated using four variables derived from the driving simulation, including average speed, relative speed difference, standard deviation of acceleration, and 85th percentile speed. Results showed that traffic control devices such as the Flashing Beacon and School Crossing Ahead Warning Assembly, the Reduce Speed and School Crossing Warning Assembly, and the School Crossing Ahead Pavement Markings were recommended for school zones adjacent to a major multilane roadway, which is characterized by a median strip, high traffic volume, high-speed traffic and the presence of pedestrian crossing signals. The School Crossing Ahead Pavement Markings were recommended for school zones on a minor two-lane roadway, which is characterized by low traffic volume, low speed, and no pedestrian crossing signals.

Analysis of crash proportion by vehicle type at traffic analysis zone level: A mixed fractional split multinomial logit modeling approach with spatial effects.

PubMed

Lee, Jaeyoung; Yasmin, Shamsunnahar; Eluru, Naveen; Abdel-Aty, Mohamed; Cai, Qing

2018-02-01

In traffic safety literature, crash frequency variables are analyzed using univariate count models or multivariate count models. In this study, we propose an alternative approach to modeling multiple crash frequency dependent variables. Instead of modeling the frequency of crashes we propose to analyze the proportion of crashes by vehicle type. A flexible mixed multinomial logit fractional split model is employed for analyzing the proportions of crashes by vehicle type at the macro-level. In this model, the proportion allocated to an alternative is probabilistically determined based on the alternative propensity as well as the propensity of all other alternatives. Thus, exogenous variables directly affect all alternatives. The approach is well suited to accommodate for large number of alternatives without a sizable increase in computational burden. The model was estimated using crash data at Traffic Analysis Zone (TAZ) level from Florida. The modeling results clearly illustrate the applicability of the proposed framework for crash proportion analysis. Further, the Excess Predicted Proportion (EPP)-a screening performance measure analogous to Highway Safety Manual (HSM), Excess Predicted Average Crash Frequency is proposed for hot zone identification. Using EPP, a statewide screening exercise by the various vehicle types considered in our analysis was undertaken. The screening results revealed that the spatial pattern of hot zones is substantially different across the various vehicle types considered. Copyright © 2017 Elsevier Ltd. All rights reserved.

Work zone traffic management synthesis : work zone pedestrian protection

DOT National Transportation Integrated Search

1997-08-01

This Long Term Pavement Performance (LTPP) data analysis was intended to examine, in a practical way, the LTPP database and to identify the site conditions and design features that significantly affect transverse joint faulting. Key products develope...

Work zone lane closure analysis model.

DOT National Transportation Integrated Search

2009-10-01

At the Alabama Department of Transportation (ALDOT), the tool used by traffic engineers to predict whether a queue will form at a freeway work zone is the Excel-based "Lane Rental Model" developed at the Oklahoma Department of Transportation (OkDOT) ...

Characteristics of worker accidents on NYSDOT construction projects.

PubMed

Mohan, Satish; Zech, Wesley C

2005-01-01

This paper aims at providing cost-effective safety measures to protect construction workers in highway work zones, based on real data. Two types of accidents that occur in work zones were: (a) construction work area accidents, and (b) traffic accidents involving construction worker(s). A detailed analysis of work zone accidents involving 36 fatalities and 3,055 severe injuries to construction workers on New York State Department of Transportation (NYSDOT) construction projects from 1990 to 2001 established that five accident types: (a) Struck/Pinned by Large Equipment, (b) Trip or Fall (elevated), (c) Contact w/Electrical or Gas Utility, (d) Struck-by Moving/Falling Load, and (e) Crane/Lift Device Failure accounted for nearly 96% of the fatal accidents, nearly 63% of the hospital-level injury accidents, and nearly 91% of the total costs. These construction work area accidents had a total cost of $133.8 million. Traffic accidents that involve contractors' employees were also examined. Statistical analyses of the traffic accidents established that five traffic accident types: (a) Work Space Intrusion, (b) Worker Struck-by Vehicle Inside Work Space, (c) Flagger Struck-by Vehicle, (d) Worker Struck-by Vehicle Entering/Exiting Work Space, and (e) Construction Equipment Struck-by Vehicle Inside Work Space accounted for nearly 86% of the fatal, nearly 70% of the hospital-level injury and minor injury traffic accidents, and $45.4 million (79.4%) of the total traffic accident costs. The results of this paper provide real statistics on construction worker related accidents reported on construction work zones. Potential preventions based on real statistics have also been suggested. The ranking of accident types, both within the work area as well as in traffic, will guide the heavy highway contractor and owner agencies in identifying the most cost effective safety preventions.

Calibration of work zone impact analysis software for Missouri.

DOT National Transportation Integrated Search

2013-12-01

This project calibrated two software programs used for estimating the traffic impacts of work zones. The WZ Spreadsheet : and VISSIM programs were recommended in a previous study by the authors. The two programs were calibrated using : field data fro...

Development of a prototype land use model for statewide transportation planning activities.

DOT National Transportation Integrated Search

2011-11-30

Future land use forecasting is an important input to transportation planning modeling. Traditionally, land use is allocated to individual : traffic analysis zones (TAZ) based on variables such as the amount of vacant land, zoning restriction, land us...

Utilization of remote traffic monitoring devices for urban freeway work zone assessment.

DOT National Transportation Integrated Search

2012-01-01

The objective of this project was to promote and facilitate analysis and evaluation of the impacts of road construction activities in Smart : Work Zone Deployment Initiative (SWZDI) states. : The two primary objectives of this project were to assess ...

Feasibility of lane closures using probe data : technical brief.

DOT National Transportation Integrated Search

2017-04-01

This study developed an on-line system analysis tool called the Work Zone Interactive : Management Application - Planning (WIMAP-P), an easy-to-use and easy-to-learn tool for : predicting the traffic impact caused by work zone lane closures on freewa...

Safety evaluation of joint and conventional lane merge configurations for freeway work zones.

PubMed

Ishak, Sherif; Qi, Yan; Rayaprolu, Pradeep

2012-01-01

Inefficient operation of traffic in work zone areas not only leads to an increase in travel time delays, queue length, and fuel consumption but also increases the number of forced merges and roadway accidents. This study evaluated the safety performance of work zones with a conventional lane merge (CLM) configuration in Louisiana. Analysis of variance (ANOVA) was used to compare the crash rates for accidents involving fatalities, injuries, and property damage only (PDO) in each of the following 4 areas: (1) advance warning area, (2) transition area, (3) work area, and (4) termination area. The analysis showed that the advance warning area had higher fatality, injury, and PDO crash rates when compared to the transition area, work area, and termination area. This finding confirmed the need to make improvements in the advance warning area where merging maneuvers take place. Therefore, a new lane merge configuration, called joint lane merge (JLM), was proposed and its safety performance was examined and compared to the conventional lane merge configuration using a microscopic simulation model (VISSIM), which was calibrated with real-world data from an existing work zone on I-55 and used to simulate a total of 25 different scenarios with different levels of demand and traffic composition. Safety performance was evaluated using 2 surrogate measures: uncomfortable decelerations and speed variance. Statistical analysis was conducted to determine whether the differences in safety performance between both configurations were significant. The safety analysis indicated that JLM outperformed CLM in most cases with low to moderate flow rates and that the percentage of trucks did not have a significant impact on the safety performance of either configuration. Though the safety analysis did not clearly indicate which lane merge configuration is safer for the overall work zone area, it was able to identify the possibly associated safety changes within the work zone area under different traffic conditions. Copyright © 2012 Taylor & Francis Group, LLC

Comparison of modeled traffic exposure zones using on-road air pollution measurements

EPA Science Inventory

Modeled traffic data were used to develop traffic exposure zones (TEZs) such as traffic delay, high volume, and transit routes in the Research Triangle area of North Carolina (USA). On-road air pollution measurements of nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxid...

Assessment of honking impact on traffic noise in urban traffic environment of Nagpur, India.

PubMed

Vijay, Ritesh; Sharma, Asheesh; Chakrabarti, Tapan; Gupta, Rajesh

2015-01-01

In context of increasing traffic noise in urban India, the objective of the research study is to assess noise due to heterogeneous traffic conditions and the impact of honking on it. Traffic volume, noise levels, honking, road geometry and vehicular speed were measured on national highway, major and minor roads in Nagpur, India. Initial study showed lack of correlation between traffic volume and equivalent noise due to some factors, later identified as honking, road geometry and vehicular speed. Further, frequency analysis of traffic noise showed that honking contributed an additional 2 to 5 dB (A) noise, which is quite significant. Vehicular speed was also found to increase traffic noise. Statistical method of analysis of variance (ANOVA) confirms that frequent honking (p < 0.01) and vehicular speed (p < 0.05) have substantial impact on traffic noise apart from traffic volume and type of road. The study suggests that honking must also be a component in traffic noise assessment and to identify and monitor "No Honking" zones in urban agglomerations.

Optimized active traffic management and speed harmonization in work zones.

DOT National Transportation Integrated Search

2014-01-01

Traffic and demand management are major strategies to control delay and congestion in : highway bottlenecks including work zones. The Federal Highway Administration (FHWA) : introduced innovative strategies, called Active Traffic and Demand Managemen...

Comparative analysis of zonal systems for macro-level crash modeling.

PubMed

Cai, Qing; Abdel-Aty, Mohamed; Lee, Jaeyoung; Eluru, Naveen

2017-06-01

Macro-level traffic safety analysis has been undertaken at different spatial configurations. However, clear guidelines for the appropriate zonal system selection for safety analysis are unavailable. In this study, a comparative analysis was conducted to determine the optimal zonal system for macroscopic crash modeling considering census tracts (CTs), state-wide traffic analysis zones (STAZs), and a newly developed traffic-related zone system labeled traffic analysis districts (TADs). Poisson lognormal models for three crash types (i.e., total, severe, and non-motorized mode crashes) are developed based on the three zonal systems without and with consideration of spatial autocorrelation. The study proposes a method to compare the modeling performance of the three types of geographic units at different spatial configurations through a grid based framework. Specifically, the study region is partitioned to grids of various sizes and the model prediction accuracy of the various macro models is considered within these grids of various sizes. These model comparison results for all crash types indicated that the models based on TADs consistently offer a better performance compared to the others. Besides, the models considering spatial autocorrelation outperform the ones that do not consider it. Based on the modeling results and motivation for developing the different zonal systems, it is recommended using CTs for socio-demographic data collection, employing TAZs for transportation demand forecasting, and adopting TADs for transportation safety planning. The findings from this study can help practitioners select appropriate zonal systems for traffic crash modeling, which leads to develop more efficient policies to enhance transportation safety. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Near real-time traffic routing

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Evaluation Of Traffic Control Devices For Rural High-Speed Maintenance Work Zones

DOT National Transportation Integrated Search

2000-10-01

This report documents the first year activities of a two-year project in which various work zone traffic control devices, treatments, and practices were implemented and evaluated. The focus was on rural high-speed work zones. Nine work zones were stu...

Data-driven traffic impact assessment tool for work zones.

DOT National Transportation Integrated Search

2017-03-01

Traditionally, traffic impacts of work zones have been assessed using planning software such as Quick Zone, custom spreadsheets, and others. These software programs generate delay, queuing, and other mobility measures but are difficult to validate du...

Modeling merging behavior at lane drops.

DOT National Transportation Integrated Search

2015-02-01

In work-zone configurations where lane drops are present, merging of traffic at the taper presents an operational concern. In : addition, as flow through the work zone is reduced, the relative traffic safety of the work zone is also reduced. Improvin...

Investigation of work zone crash casualty patterns using association rules.

PubMed

Weng, Jinxian; Zhu, Jia-Zheng; Yan, Xuedong; Liu, Zhiyuan

2016-07-01

Investigation of the casualty crash characteristics and contributory factors is one of the high-priority issues in traffic safety analysis. In this paper, we propose a method based on association rules to analyze the characteristics and contributory factors of work zone crash casualties. A case study is conducted using the Michigan M-94/I-94/I-94BL/I-94BR work zone crash data from 2004 to 2008. The obtained association rules are divided into two parts including rules with high-lift, and rules with high-support for the further analysis. The results show that almost all the high-lift rules contain either environmental or occupant characteristics. The majority of association rules are centered on specific characteristics, such as drinking driving, the highway with more than 4 lanes, speed-limit over 40mph and not use of traffic control devices. It should be pointed out that some stronger associated rules were found in the high-support part. With the network visualization, the association rule method can provide more understandable results for investigating the patterns of work zone crash casualties. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of work zone split traffic symbol sign : final report.

DOT National Transportation Integrated Search

2017-08-01

Effective signage that is easy to understand facilitates safe driving through a work zone. While the guidance for work zone signage in the Manual on Uniform Traffic Control Devices (MUTCD) is suitable for many conditions, there may be instances where...

Evaluation of temporary traffic signals in conjunction with pilot car operations at two-way long temporary work zones.

DOT National Transportation Integrated Search

2016-05-01

The primary objective of this study was to evaluate the use of Portable Traffic Signal (PTS) systems at long, rural : two-lane work zones and to compare three different conditions for controlling one-lane traffic in conjunction with pilot car : opera...

Evaluation of Traffic Information and Prediction System (TIPS) as work zone traffic control.

DOT National Transportation Integrated Search

2004-03-01

As part of a pavement rehabilitation project on I-64, the Traffic Information and Prediction System (TIPS) was installed as a a means of providing real-time data for motorists in advance and through the work zone. This system collects real-time data ...

Crash characteristics at work zones

DOT National Transportation Integrated Search

2001-05-01

Work zones tend to cause hazardous conditions for vehicle drivers and construction workers since they generate conflicts between construction activities and the traffic, and therefore aggravate the existing traffic conditions.

Evaluation of temporary traffic signals in conjunction with pilot car operations at two-way long temporary work zones : technical summary.

DOT National Transportation Integrated Search

2016-05-01

The primary objective of this study was to evaluate the use of Portable Traffic Signal (PTS) systems at long, rural two-lane work zones and to compare three different conditions for controlling one-lane traffic in conjunction with pilot car operation...

Evaluation of innovative traffic safety devices at short-term work zones.

DOT National Transportation Integrated Search

2013-08-01

The objective of this study was to investigate and evaluate the usage and effectiveness of innovative traffic control : devices that can be used in short-term work zones. Any device to be used in short-term work zones should command : the respect of ...

A population study on risk factors for insomnia among adult Japanese women: a possible effect of road traffic volume.

PubMed

Kageyama, T; Kabuto, M; Nitta, H; Kurokawa, Y; Taira, K; Suzuki, S; Takemoto, T

1997-11-01

In an effort to identify risk factors for insomnia and determine the contribution of nightime road traffic volume to insomnia in the general population, a questionnaire survey was carried out among 3,600 adult Japanese women living in eight urban residential areas. The crude prevalence rate of insomnia was 11.2%. Multivariate analysis revealed that aging, living with a child/children aged six or younger, undergoing medical treatment, experiencing major life events, having an irregular bedtime, having a sleep apnealike symptom, and living near a road with a heavy volume of traffic are risk factors for insomnia. Taking into account other risk factors, there was a level-response relationship between the nighttime traffic volume of main roads and the risk of insomnia in the subjects living in the zones 0-20 m from these roads. These results suggest that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas. To confirm this, a further study on noise exposure is needed.

Improvements and new concepts for traffic control in work zones. Volume 4, Speed control in work zones

DOT National Transportation Integrated Search

1985-09-01

Tile objective of the research was to determine or develop effective methods of s1owing traffic to an acceptable speed in work zones. Factors considered in the study included cost, motorist and worker safety, institutional constraints, and probabilit...

Evaluation of innovative traffic safety devices at short-term work zones : technical summary.

DOT National Transportation Integrated Search

2013-08-01

The objective of this study was to investigate and evaluate the usage and effectiveness of innovative traffic control devices that can be used in short-term work zones. Any device to be used in short-term work zones should command the respect of driv...

Evaluation of data from test application of optical speed bars to highway work zones

DOT National Transportation Integrated Search

2004-08-01

The proximity of traffic and workers in highway work zones demand that safety be a high priority. : The issue of traffic speeds in highway work zones has long been an issue receiving much attention. Over the : past three decades, many different measu...

Evaluation Of Traffic Control Devices For Rural High-Speed Maintenance Work Zones: Second Year Activities And Final Recommendations

DOT National Transportation Integrated Search

2000-10-01

This report documents the second year of a two-year project to evaluate the effectiveness of innovative work zone traffic control devices. Researchers evaluated these devices at short-term rural work zones. During the second year of the project, seve...

Assessment of Indoor and Outdoor PM Species at Schools and Residences in a High-Altitude Ecuadorian Urban Center

PubMed Central

Raysoni, Amit U.; Armijos, Rodrigo X.; Weigel, M. Margaret; Montoya, Teresa; Eschanique, Patricia; Racines, Marcia; Li, Wen-Whai

2016-01-01

An air monitoring campaign to assess children’s environmental exposures in schools and residences, both indoors and outdoors, was conducted in 2010 in three low-income neighborhoods in Z1(north), Z2(central), and Z3(southeast) zones of Quito, Ecuador - a major urban center of 2.2 million inhabitants situated 2850 meters above sea level in a narrow mountainous basin. Z1 zone, located in northern Quito, historically experienced emissions from quarries and moderate traffic. Z2 zone was influenced by heavy traffic in contrast to Z3 zone which experienced low traffic densities. Weekly averages of PM samples were collected at schools (one in each zone) and residences (Z1=47, Z2=45, and Z3=41) every month, over a twelve-month period at the three zones. Indoor PM2.5 concentrations ranged from 10.6±4.9 μg/m3 (Z1 school) to 29.0±30.5 μg/m3 (Z1 residences) and outdoor PM2.5 concentrations varied from 10.9±3.2 μg/m3 (Z1 school) to 14.3±10.1 μg/m3 (Z2 residences), across the three zones. The lowest values for PM10–2.5 for indoor and outdoor microenvironments were recorded at Z2 school, 5.7±2.8 μg/m3 and 7.9±2.2 μg/m3, respectively. Outdoor school PM concentrations exhibited stronger associations with corresponding indoor values making them robust proxies for indoor exposures in naturally ventilated Quito public schools. Correlation analysis between the school and residential PM size fractions and the various pollutant and meteorological parameters from central ambient monitoring (CAM) sites suggested varying degrees of temporal relationship. Strong positive correlation was observed for outdoor PM2.5 at Z2 school and its corresponding CAM site (r=0.77) suggesting common traffic related emissions. Spatial heterogeneity in PM2.5 concentrations between CAM network and sampled sites was assessed using Coefficient of Divergence (COD) analysis. COD values were lower when CAM sites were paired with outdoor measurements (< 0.2) and higher when CAM and indoor values were compared (> 0.2), suggesting that CAM network in Quito may not represent actual indoor exposures. PMID:27149144

Phase II, improved work zone design guidelines and enhanced model of traffic delays in work zones : final report, March 2009.

DOT National Transportation Integrated Search

2009-03-01

This project contains three major parts. In the first part a digital computer simulation model was developed with the aim to model the traffic through a freeway work zone situation. The model was based on the Arena simulation software and used cumula...

Phase II, improved work zone design guidelines and enhanced model of traffic delays in work zones : executive summary report.

DOT National Transportation Integrated Search

2009-03-01

This project contains three major parts. In the first part a digital computer simulation model was developed with the aim to model the traffic through a freeway work zone situation. The model was based on the Arena simulation software and used cumula...

Work Zone Design and Operations Enhancements

DOT National Transportation Integrated Search

2010-02-01

Oregon Department of Transportation contractors are required to implement Traffic Control Plans (TCPs) to protect and direct traffic through work zones. The design and implementation of TCPs have shown variation from project-to-project across the Sta...

Work zone and operation enhancements.

DOT National Transportation Integrated Search

2010-02-01

Oregon Department of Transportation contractors are required to implement Traffic Control Plans (TCPs) to protect and direct traffic through work zones. The design and implementation of TCPs have shown variation from project-to-project across the Sta...

Improving Night Work Zone Traffic Control

DOT National Transportation Integrated Search

1999-08-01

The purpose of this study was to examine traffic control for night work zones from the perspective of both transportation agencies and motorists. This was accomplished by investigating practices of state departments of transportation (DOTs), identify...

Modeling work zone crash frequency by quantifying measurement errors in work zone length.

PubMed

Yang, Hong; Ozbay, Kaan; Ozturk, Ozgur; Yildirimoglu, Mehmet

2013-06-01

Work zones are temporary traffic control zones that can potentially cause safety problems. Maintaining safety, while implementing necessary changes on roadways, is an important challenge traffic engineers and researchers have to confront. In this study, the risk factors in work zone safety evaluation were identified through the estimation of a crash frequency (CF) model. Measurement errors in explanatory variables of a CF model can lead to unreliable estimates of certain parameters. Among these, work zone length raises a major concern in this analysis because it may change as the construction schedule progresses generally without being properly documented. This paper proposes an improved modeling and estimation approach that involves the use of a measurement error (ME) model integrated with the traditional negative binomial (NB) model. The proposed approach was compared with the traditional NB approach. Both models were estimated using a large dataset that consists of 60 work zones in New Jersey. Results showed that the proposed improved approach outperformed the traditional approach in terms of goodness-of-fit statistics. Moreover it is shown that the use of the traditional NB approach in this context can lead to the overestimation of the effect of work zone length on the crash occurrence. Copyright © 2013 Elsevier Ltd. All rights reserved.

Freight Terminals Operating Environment

DOT National Transportation Integrated Search

1981-06-01

The research analysis has been directed toward (1) developing a realistic, quantitative description of the structure of the economic zones that are centered upon medium-size urban areas, (2) determining the nature of traffic in manufactured goods whi...

Crash Tests of Work Zone Traffic Control Devices

DOT National Transportation Integrated Search

1990-02-01

Full-scale vehicle crash tests evaluated performance of typical work zone traffic control devices. Modified test procedures and evaluation criteria from NCHRP Report 230 were used in 108 tests, providing significant insight into impact performance. P...

Development of recommendations for arterial lane closures to optimize traffic operations.

DOT National Transportation Integrated Search

2013-01-01

The 2010 FDOT Design Standards provide information regarding traffic control through work zones at multilane arterials. : However, there are currently no quantitative guidelines for optimizing signal control around work zones. The objective of this :...

Noise level arrangement in determined zones of homogenous development of green areas on the example of the spa park in Inowrocław

NASA Astrophysics Data System (ADS)

Sztubecka, Małgorzata; Skiba, Marta

2016-11-01

Noise measurements are usually carried out in developed areas as well as in the surroundings of traffic routes providing basis for actions in order to limit its influence on the neighboring areas. Noise measurements in park areas are rare due to belief that these areas are silent zones. Such attitude cannot be justified. This article aims to the assessment of noise appearing in determined subzones of the spa park in Inowrocław. From the research carried out it can be noticed that traffic noise does not have any important meaning for the acoustic climate of the park. It is the people who stay there who generate more noise. Comparative analysis proves the appearance and penetration of noise from the zones with greater level of noise to the ones with lower amount.

Work zone design and operation enhancements : final report, March 2010.

DOT National Transportation Integrated Search

2010-02-01

Oregon Department of Transportation contractors are required to implement Traffic Control Plans (TCPs) to protect and direct traffic through work zones. The design and implementation of TCPs have shown variation from project-to-project across the Sta...

Optimization of Highway Work Zone Decisions Considering Short-Term and Long-Term Impacts

DTIC Science & Technology

2010-01-01

strategies which can minimize the one-time work zone cost. Considering the complex and combinatorial nature of this optimization problem, a heuristic...combination of lane closure and traffic control strategies which can minimize the one-time work zone cost. Considering the complex and combinatorial nature ...zone) NV # the number of vehicle classes NPV $ Net Present Value p’(t) % Adjusted traffic diversion rate at time t p(t) % Natural diversion rate

Effects of work zone configurations and traffic density on performance variables and subjective workload.

PubMed

Shakouri, Mahmoud; Ikuma, Laura H; Aghazadeh, Fereydoun; Punniaraj, Karthy; Ishak, Sherif

2014-10-01

This paper investigates the effect of changing work zone configurations and traffic density on performance variables and subjective workload. Data regarding travel time, average speed, maximum percent braking force and location of lane changes were collected by using a full size driving simulator. The NASA-TLX was used to measure self-reported workload ratings during the driving task. Conventional lane merge (CLM) and joint lane merge (JLM) were modeled in a driving simulator, and thirty participants (seven female and 23 male), navigated through the two configurations with two levels of traffic density. The mean maximum braking forces was 34% lower in the JLM configuration, and drivers going through the JLM configuration remained in the closed lane longer. However, no significant differences in speed were found between the two merge configurations. The analysis of self-reported workload ratings show that participants reported 15.3% lower total workload when driving through the JLM. In conclusion, the implemented changes in the JLM make it a more favorable merge configuration in both high and low traffic densities in terms of optimizing traffic flow by increasing the time and distance cars use both lanes, and in terms of improving safety due to lower braking forces and lower reported workload. Copyright © 2014 Elsevier Ltd. All rights reserved.

Delineation systems for temporary traffic barriers in work zones.

DOT National Transportation Integrated Search

1986-01-01

Providing for the safety of traffic traversing construction and maintenance work zones is becoming increasingly complex, and over the past several years, temporary concrete barriers have come into use as a means of protecting work crews as well as mo...

Portable traffic management system smart work zone application : operational test evaluation report

DOT National Transportation Integrated Search

1997-05-01

As part of its statewide Intelligent Transportation System (ITS), The Minnesota Department of Transportation (Mn/DOT) sponsored an operational test of the Portable Traffic Management System (PTMS) in a work zone application in cooperation with its pr...

Evaluation of modified work zone traffic control devices at business accesses

DOT National Transportation Integrated Search

2001-01-01

Modified work zone traffic control devices at business accesses were evaluated on two Oregon Department of Transportation (ODOT) projects in 1999 and 2000. On one section project, blue Temporary Business Access" signs were used at business accesses d...

Uncertainty analysis of accident notification time and emergency medical service response time in work zone traffic accidents.

PubMed

Meng, Qiang; Weng, Jinxian

2013-01-01

Taking into account the uncertainty caused by exogenous factors, the accident notification time (ANT) and emergency medical service (EMS) response time were modeled as 2 random variables following the lognormal distribution. Their mean values and standard deviations were respectively formulated as the functions of environmental variables including crash time, road type, weekend, holiday, light condition, weather, and work zone type. Work zone traffic accident data from the Fatality Analysis Report System between 2002 and 2009 were utilized to determine the distributions of the ANT and the EMS arrival time in the United States. A mixed logistic regression model, taking into account the uncertainty associated with the ANT and the EMS response time, was developed to estimate the risk of death. The results showed that the uncertainty of the ANT was primarily influenced by crash time and road type, whereas the uncertainty of EMS response time is greatly affected by road type, weather, and light conditions. In addition, work zone accidents occurring during a holiday and in poor light conditions were found to be statistically associated with a longer mean ANT and longer EMS response time. The results also show that shortening the ANT was a more effective approach in reducing the risk of death than the EMS response time in work zones. To shorten the ANT and the EMS response time, work zone activities are suggested to be undertaken during non-holidays, during the daytime, and in good weather and light conditions.

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2014 CFR

2014-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2012 CFR

2012-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

33 CFR 209.138a - Authorization for exploratory drilling in the Gulf of Santa Catalina, Calif.

Code of Federal Regulations, 2013 CFR

2013-07-01

... feasible to perform exploratory work from outside the traffic lanes or 1/4 mile buffer zones, or... cables, anchors, buoys, or other associated equipment within the traffic lanes, 1/4 mile buffer zones, or...

An evaluation of school zone traffic control strategies : phase I.

DOT National Transportation Integrated Search

2013-03-01

Throughout the past six decades, the predominant mode of student transport has shifted from walkingto riding in a school bus or personal vehicle which has impacted both the safety and efficiency of school zone traffic control strategies. In order to ...

Using historical crash data as part of traffic work zone safety planning and project management strategies.

DOT National Transportation Integrated Search

2014-07-01

This funding enabled the project entitled, USING HISTORICAL CRASH DATA AS PART OF TRAFFIC WORK ZONE SAFETY : PLANNING AND PROJECT MANAGEMENT STRATEGIES to address the following: : Evaluate current organizational strategies with respect to w...

Improving safety in high-speed work zones : a Super 70 study : [summary].

DOT National Transportation Integrated Search

2011-08-01

Highway work zones, particularly those on urban high-speed roads, require special attention and adequate traffic management to reduce the adverse impact of altered geometry and traffic that differ from typical conditions. Super 70 was an urban recons...

Improved work zone design guidelines and enhanced model of travel delays in work zones : Phase I, portability and scalability of interarrival and service time probability distribution functions for different locations in Ohio and the establishment of impr

DOT National Transportation Integrated Search

2006-01-01

Problem: Work zones on heavily traveled divided highways present problems to motorists in the form of traffic delays and increased accident risks due to sometimes reduced motorist guidance, dense traffic, and other driving difficulties. To minimize t...

Assessment of indoor and outdoor PM species at schools and residences in a high-altitude Ecuadorian urban center.

PubMed

Raysoni, Amit U; Armijos, Rodrigo X; Weigel, M Margaret; Montoya, Teresa; Eschanique, Patricia; Racines, Marcia; Li, Wen-Whai

2016-07-01

An air monitoring campaign to assess children's environmental exposures in schools and residences, both indoors and outdoors, was conducted in 2010 in three low-income neighborhoods in Z1 (north), Z2 (central), and Z3 (southeast) zones of Quito, Ecuador - a major urban center of 2.2 million inhabitants situated 2850 m above sea level in a narrow mountainous basin. Z1 zone, located in northern Quito, historically experienced emissions from quarries and moderate traffic. Z2 zone was influenced by heavy traffic in contrast to Z3 zone which experienced low traffic densities. Weekly averages of PM samples were collected at schools (one in each zone) and residences (Z1 = 47, Z2 = 45, and Z3 = 41) every month, over a twelve-month period at the three zones. Indoor PM2.5 concentrations ranged from 10.6 ± 4.9 μg/m(3) (Z1 school) to 29.0 ± 30.5 μg/m(3) (Z1 residences) and outdoor PM2.5 concentrations varied from 10.9 ± 3.2 μg/m(3) (Z1 school) to 14.3 ± 10.1 μg/m(3) (Z2 residences), across the three zones. The lowest values for PM10-2.5 for indoor and outdoor microenvironments were recorded at Z2 school, 5.7 ± 2.8 μg/m(3) and 7.9 ± 2.2 μg/m(3), respectively. Outdoor school PM concentrations exhibited stronger associations with corresponding indoor values making them robust proxies for indoor exposures in naturally ventilated Quito public schools. Correlation analysis between the school and residential PM size fractions and the various pollutant and meteorological parameters from central ambient monitoring (CAM) sites suggested varying degrees of temporal relationship. Strong positive correlation was observed for outdoor PM2.5 at Z2 school and its corresponding CAM site (r = 0.77) suggesting common traffic related emissions. Spatial heterogeneity in PM2.5 concentrations between CAM network and sampled sites was assessed using Coefficient of Divergence (COD) analysis. COD values were lower when CAM sites were paired with outdoor measurements (<0.2) and higher when CAM and indoor values were compared (>0.2), suggesting that CAM network in Quito may not represent actual indoor exposures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnitude and outcomes of road traffic accidents at Hospitals in Wolaita Zone, SNNPR, Ethiopia.

PubMed

Hailemichael, Feleke; Suleiman, Mohammed; Pauolos, Wondimagegn

2015-04-09

A Road traffic accident is an incident on a way or street open to public traffic, resulting in one or more persons being killed or injured, and involving at least one moving vehicle. The aim of this study is to assess magnitude and outcome of road traffic accidents among trauma victims at hospitals in Wolaita zone. A cross sectional hospital based study design using retrospective chart review was conducted from March 5th to March 25th, 2014. Simple random sampling technique was applied to identify sample population. The data was entered in to Epi info version 3.5.1 and transferred to SPSS version 16 for further analysis. A total of 384 trauma victims were incorporated in the study of which 240 (62.5%) were due to road traffic accidents. The majority of patients were male 298 (77.6%) and most commonly aged between 20-29 (35.42%). The principal outcome of injury was more commonly lower extremity (182 patients, 47.4%), compared to upper extremity (126 patients, 32.8%). Of all trauma patient presenting to hospitals (62.5%) are the result of road traffic accident. Hence, the provision of tailored messages to all members of the community regarding knowledge and practices of road safety measures like appropriate use of pavements by pedestrians and avoiding risky driving behaviors. Besides this make use of compulsory motorcycle helmets would appear to be a very important intervention.

Transit accessibility and labor force participation rate of at-risk groups : Dade County

DOT National Transportation Integrated Search

1997-06-01

This report examines whether transit accessibility to jobs from individual traffic analysis zones has an impact on employment of different racial/ethnic groups. Demonstrations of cross-town bus routes making suburban employment more accessible have b...

Effect of flaggers and spotters in directing work zone traffic for Illinois expressways and freeways.

DOT National Transportation Integrated Search

2014-01-01

This research project focused on assessing the effectiveness and essential role of flaggers and spotters in : directing traffic for expressway and freeway work zones in Illinois with a posted speed limit greater than 40 mph. : The objectives of this ...

Impact of lane closures on roadway capacity, phase 2 : [summary].

DOT National Transportation Integrated Search

2014-01-01

Maintenance or construction on two-lane roads often requires setting up a work zone which closes one lane and uses the other for both traffic directions. Workers posted at each end of the work zone allow traffic to flow alternately one way and then t...

A demonstration of expert systems applications in transportation engineering : volume II, TRANZ, a prototype expert system for traffic control in highway work zones.

DOT National Transportation Integrated Search

1988-01-01

The development of a prototype knowledge-based expert system (KBES) for selecting appropriate traffic control strategies and management techniques around highway work zones was initiated. This process was encompassed by the steps that formulate the p...

Development and MASH full-scale crash testing of a high-mounting-height temporary single sign support with aluminum sign.

DOT National Transportation Integrated Search

2013-03-01

Work zone traffic control devices such as temporary single sign supports are a primary means to communicate : information to motorists in work zone areas. The Federal Highway Administration and the Manual on Uniform Traffic : Control Devices require ...

Investigating the relationship between jobs-housing balance and traffic safety.

PubMed

Xu, Chengcheng; Li, Haojie; Zhao, Jingya; Chen, Jun; Wang, Wei

2017-10-01

This study aimed to investigate the effects of jobs-housing balance on traffic safety. The crash, demographic characteristics, employment, road network, household characteristics and traffic data were collected from the Los Angeles in 2010. One-way ANOVA tests indicated that the jobs-housing ratio significantly affects traffic safety in terms of crash frequency at traffic analysis zone (TAZ). To quantify the safety impacts of jobs-housing balance, the semi-parametric geographically weighted Poisson regression (S-GWPR) was further used to link crash frequency at TAZ with jobs-housing ratio and other contributing factors. The S-GWPR provides better fitness to the data than do the generalized linear regression, as the S-GWPR accounts for the spatial heterogeneity. The S-GWPR results showed that the jobs-housing relationship has a significant association with crash frequency at TAZ when the factors of traffic, network, and household characteristics are controlled. Crash frequency at TAZ level increases with an increase in the jobs-housing ratio. To further investigate the interactive effects between jobs-housing ratio and other factors, a comparative analysis was conducted to compare the variable elasticities under different jobs-housing ratios. The results indicate considerable interactive effects that traffic conditions and road network characteristics have different effects on crash frequency under various jobs-housing ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparing microscopic activity-based and traditional models of travel demand : an Austin area case study

DOT National Transportation Integrated Search

2007-09-01

Two competing approaches to travel demand modeling exist today. The more traditional 4-step travel demand models rely on aggregate demographic data at a traffic analysis zone (TAZ) level. Activity-based microsimulation methods employ more robus...

a Cross-Sectional Study on Insomnia among Japanese Adult Women in Relation to Night-Time Road Traffic Noise

NASA Astrophysics Data System (ADS)

Kageyama, T.; Kabuto, M.; Nitta, N.; Kurokawa, Y.; Taira, K.; Suzuki, S.; Takemoto, T.

1997-08-01

In an effort to determine the contribution of night-time road traffic noise to insomnia in the general population, 3600 adult Japanese women living in urban residential areas were surveyed. Living near a road with a heavy traffic volume is one of the risk factors for insomnia. The risk for insomnia in the zones 0-20 m from the main roads increased linearly with the night-time traffic volume. This suggests that road traffic noise raises the sound level in bedrooms in such zones, and consequently the prevalence rate of insomnia among the residents, and that noise-induced insomnia is an important public health problem, at least in highly urbanized areas.

Community structure in traffic zones based on travel demand

NASA Astrophysics Data System (ADS)

Sun, Li; Ling, Ximan; He, Kun; Tan, Qian

2016-09-01

Large structure in complex networks can be studied by dividing it into communities or modules. Urban traffic system is one of the most critical infrastructures. It can be abstracted into a complex network composed of tightly connected groups. Here, we analyze community structure in urban traffic zones based on the community detection method in network science. Spectral algorithm using the eigenvectors of matrices is employed. Our empirical results indicate that the traffic communities are variant with the travel demand distribution, since in the morning the majority of the passengers are traveling from home to work and in the evening they are traveling a contrary direction. Meanwhile, the origin-destination pairs with large number of trips play a significant role in urban traffic network's community division. The layout of traffic community in a city also depends on the residents' trajectories.

Meeting the customer's needs for mobility and safety during construction and maintenance operations : model work zone traffic management program and self evaluation guide

DOT National Transportation Integrated Search

1998-09-01

This model program was developed by combining traffic management concepts reported in research studies and papers with the effective techniques currently being used by States to minimize motorist delays and enhance work zone safety. This model is pre...

Maintenance of Traffic for Innovative Geometric Design Work Zones

DOT National Transportation Integrated Search

2015-12-01

Currently there are no guidelines within the Manual on Uniform Traffic Control Devices (MUTCD) on construction phasing and maintenance of traffic (MOT) for retrofit construction and maintenance projects involving innovative geometric designs. The res...

Macro-level pedestrian and bicycle crash analysis: Incorporating spatial spillover effects in dual state count models.

PubMed

Cai, Qing; Lee, Jaeyoung; Eluru, Naveen; Abdel-Aty, Mohamed

2016-08-01

This study attempts to explore the viability of dual-state models (i.e., zero-inflated and hurdle models) for traffic analysis zones (TAZs) based pedestrian and bicycle crash frequency analysis. Additionally, spatial spillover effects are explored in the models by employing exogenous variables from neighboring zones. The dual-state models such as zero-inflated negative binomial and hurdle negative binomial models (with and without spatial effects) are compared with the conventional single-state model (i.e., negative binomial). The model comparison for pedestrian and bicycle crashes revealed that the models that considered observed spatial effects perform better than the models that did not consider the observed spatial effects. Across the models with spatial spillover effects, the dual-state models especially zero-inflated negative binomial model offered better performance compared to single-state models. Moreover, the model results clearly highlighted the importance of various traffic, roadway, and sociodemographic characteristics of the TAZ as well as neighboring TAZs on pedestrian and bicycle crash frequency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of Air Pollution and the Introduction of the London Low Emission Zone on the Prevalence of Respiratory and Allergic Symptoms in Schoolchildren in East London: A Sequential Cross-Sectional Study.

PubMed

Wood, Helen E; Marlin, Nadine; Mudway, Ian S; Bremner, Stephen A; Cross, Louise; Dundas, Isobel; Grieve, Andrew; Grigg, Jonathan; Jamaludin, Jeenath B; Kelly, Frank J; Lee, Tak; Sheikh, Aziz; Walton, Robert; Griffiths, Christopher J

2015-01-01

The adverse effects of traffic-related air pollution on children's respiratory health have been widely reported, but few studies have evaluated the impact of traffic-control policies designed to reduce urban air pollution. We assessed associations between traffic-related air pollutants and respiratory/allergic symptoms amongst 8-9 year-old schoolchildren living within the London Low Emission Zone (LEZ). Information on respiratory/allergic symptoms was obtained using a parent-completed questionnaire and linked to modelled annual air pollutant concentrations based on the residential address of each child, using a multivariable mixed effects logistic regression analysis. Exposure to traffic-related air pollutants was associated with current rhinitis: NOx (OR 1.01, 95% CI 1.00-1.02), NO2 (1.03, 1.00-1.06), PM10 (1.16, 1.04-1.28) and PM2.5 (1.38, 1.08-1.78), all per μg/m3 of pollutant, but not with other respiratory/allergic symptoms. The LEZ did not reduce ambient air pollution levels, or affect the prevalence of respiratory/allergic symptoms over the period studied. These data confirm the previous association between traffic-related air pollutant exposures and symptoms of current rhinitis. Importantly, the London LEZ has not significantly improved air quality within the city, or the respiratory health of the resident population in its first three years of operation. This highlights the need for more robust measures to reduce traffic emissions.

Traffic control strategies for congested freeways and work zones.

DOT National Transportation Integrated Search

2008-10-01

The primary objective of the research was to identify and evaluate effective ways of improving traffic operations and : safety on congested freeways. There was particular interest in finding condition-responsive traffic control solutions : for the fo...

Binational school-based monitoring of traffic-related air pollutants in El Paso, Texas (USA) and Ciudad Juárez, Chihuahua (México).

PubMed

Raysoni, Amit U; Sarnat, Jeremy A; Sarnat, Stefanie Ebelt; Garcia, Jośe Humberto; Holguin, Fernando; Luèvano, Silvia Flores; Li, Wen-Whai

2011-10-01

Paired indoor and outdoor concentrations of fine and coarse particulate matter (PM), PM2.5 reflectance [black carbon(BC)], and nitrogen dioxide (NO(2)) were determined for sixteen weeks in 2008 at four elementary schools (two in high and two in low traffic density zones) in a U.S.-Mexico border community to aid a binational health effects study. Strong spatial heterogeneity was observed for all outdoor pollutant concentrations. Concentrations of all pollutants, except coarse PM, were higher in high traffic zones than in the respective low traffic zones. Black carbon and NO(2) appear to be better traffic indicators than fine PM. Indoor air pollution was found to be well associated with outdoor air pollution, although differences existed due to uncontrollable factors involving student activities and building/ventilation configurations. Results of this study indicate substantial spatial variability of pollutants in the region, suggesting that children's exposures to these pollutants vary based on the location of their school. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of the performance of portable precast concrete traffic barriers.

DOT National Transportation Integrated Search

1978-01-01

The portable precast concrete traffic barrier is used to separate high speed vehicular traffic and construction activities. However, since there was a lack of information on the barrier's performance in a construction zone environment, officials of t...

Satellite-aided coastal zone monitoring and vessel traffic system

NASA Technical Reports Server (NTRS)

Baker, J. L.

1981-01-01

The development and demonstration of a coastal zone monitoring and vessel traffic system is described. This technique uses a LORAN-C navigational system and relays signals via the ATS-3 satellite to a computer driven color video display for real time control. Multi-use applications of the system to search and rescue operations, coastal zone management and marine safety are described. It is emphasized that among the advantages of the system are: its unlimited range; compatibility with existing navigation systems; and relatively inexpensive cost.

Determining the drivers' acceptance of EFTCD in highway work zones.

PubMed

Bai, Yong; Li, Yingfeng

2011-05-01

Traffic safety is a major concern in the temporary one-lane, two-way highway work zones due to the increasing of construction and maintenance operations. To prevent rear-end crashes and to mitigate the severity of these crashes caused by the inattentive driving, the utilization of the Emergency Flasher Traffic Control Device (EFTCD) was under consideration by government agencies, in addition to existing temporary traffic control devices installed in the one-lane, two-way highway work zones. The EFTCD was a newly proposed traffic warning device implemented through the use of vehicles' hazard warning flashers. The primary objective of the research project was to investigate the drivers' acceptance of the proposed EFTCD by measuring the mean speed changes of vehicles with and without EFTCD and by evaluating the drivers' opinions of the EFTCD using the survey method. Field experimental results revealed that the EFTCD effectively reduced the mean vehicle speeds in the upstream of two work zones. A slow speed is more likely to reduce the severity of a crash in work zones. In addition, survey results indicated that 60% of the drivers thought the EFTCD signified a need for speed reduction and 82% of drivers recommended the implementation of the EFTCD in one-lane, two-way work zones. These results provide the necessary scientific justifications for the government agencies to decide if the EFTCD should be implemented in the one-lane, two-way highway work zones to prevent rear-end crashes and to mitigate the severity of these crashes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effect of changing driving conditions on driver behavior towards design of a safe and efficient traffic system.

DOT National Transportation Integrated Search

2013-12-01

This simulation-based study explores the effects of different work zone configurations, varying distances : between traffic signs, traffic density and individual differences on drivers behavior. Conventional Lane : Merge (CLM) and Joint Lane Merge...

Spatial regression analysis of traffic crashes in Seoul.

PubMed

Rhee, Kyoung-Ah; Kim, Joon-Ki; Lee, Young-ihn; Ulfarsson, Gudmundur F

2016-06-01

Traffic crashes can be spatially correlated events and the analysis of the distribution of traffic crash frequency requires evaluation of parameters that reflect spatial properties and correlation. Typically this spatial aspect of crash data is not used in everyday practice by planning agencies and this contributes to a gap between research and practice. A database of traffic crashes in Seoul, Korea, in 2010 was developed at the traffic analysis zone (TAZ) level with a number of GIS developed spatial variables. Practical spatial models using available software were estimated. The spatial error model was determined to be better than the spatial lag model and an ordinary least squares baseline regression. A geographically weighted regression model provided useful insights about localization of effects. The results found that an increased length of roads with speed limit below 30 km/h and a higher ratio of residents below age of 15 were correlated with lower traffic crash frequency, while a higher ratio of residents who moved to the TAZ, more vehicle-kilometers traveled, and a greater number of access points with speed limit difference between side roads and mainline above 30 km/h all increased the number of traffic crashes. This suggests, for example, that better control or design for merging lower speed roads with higher speed roads is important. A key result is that the length of bus-only center lanes had the largest effect on increasing traffic crashes. This is important as bus-only center lanes with bus stop islands have been increasingly used to improve transit times. Hence the potential negative safety impacts of such systems need to be studied further and mitigated through improved design of pedestrian access to center bus stop islands. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spatial Analysis of Traffic and Routing Path Methods for Tsunami Evacuation

NASA Astrophysics Data System (ADS)

Fakhrurrozi, A.; Sari, A. M.

2018-02-01

Tsunami disaster occurred relatively very fast. Thus, it has a very large-scale impact on both non-material and material aspects. Community evacuation caused mass panic, crowds, and traffic congestion. A further research in spatial based modelling, traffic engineering and splitting zone evacuation simulation is very crucial as an effort to reduce higher losses. This topic covers some information from the previous research. Complex parameters include route selection, destination selection, the spontaneous timing of both the departure of the source and the arrival time to destination and other aspects of the result parameter in various methods. The simulation process and its results, traffic modelling, and routing analysis emphasized discussion which is the closest to real conditions in the tsunami evacuation process. The method that we should highlight is Clearance Time Estimate based on Location Priority in which the computation result is superior to others despite many drawbacks. The study is expected to have input to improve and invent a new method that will be a part of decision support systems for disaster risk reduction of tsunamis disaster.

47 CFR 69.112 - Direct-trunked transport.

Code of Federal Regulations, 2012 CFR

2012-10-01

... assigned to the lowest priced density pricing zone (zone 1) under an approved density pricing zone plan as... cross-connects for the transmission of switched traffic per office assigned to the lowest priced density pricing zone (zone 1). (g) In study areas in which the telephone company has implemented density zone...

Determination of network origin-destination matrices using partial link traffic counts and virtual sensor information in an integrated corridor management framework.

DOT National Transportation Integrated Search

2014-04-01

Trip origin-destination (O-D) demand matrices are critical components in transportation network : modeling, and provide essential information on trip distributions and corresponding spatiotemporal : traffic patterns in traffic zones in vehicular netw...

Crash characteristics at work zones.

DOT National Transportation Integrated Search

2002-01-01

Work zones tend to cause hazardous conditions for drivers and construction workers since they generate conflicts between construction activities and traffic. A clear understanding of the characteristics of work zone crashes will enhance the selection...

Downtown Crossing: Auto Restricted Zone in Boston

DOT National Transportation Integrated Search

1982-07-01

The Downtown Crossing auto restricted zone, implemented in 1978, involved the : elimination of all auto traffic froma zone of twelve blocks encompassing six : different streets in Bostn's central business district. Some of the blocks were : pedestria...

Research notes : helping businesses in work zones.

DOT National Transportation Integrated Search

2001-03-01

Many business owners fear that highway construction projects will significantly reduce traffic to their businesses. Customers complain about the difficulty in finding business driveways in work zones. Drivers are guided through most work zone using o...

Assessment of Trace Metals Concentration in Tree Barks as Indicator of Atmospheric Pollution within Ibadan City, South-West, Nigeria

PubMed Central

Ejidike, Ikechukwu P.; Onianwa, Percy C.

2015-01-01

Tree bark species were randomly collected from 65 sites having different anthropogenic activities, such as industrial, high traffic commercial, residential high and residential low traffic volume areas of Ibadan City, Nigeria. Levels of Cd, Cu, Pb, Zn, Co, and Cr of the dry-ashed bark samples were determined by AAS. The mean metal concentrations (mg kg−1) in samples from industrial zone were found as Pb: 3.67 ± 1.97, Cd: 0.10 ± 0.07, Zn: 30.96 ± 32.05, Cu: 7.29 ± 5.17, Co: 0.91 ± 0.58, and Cr: 2.61 ± 1.84. The trend of mean trace metal concentrations at high traffic commercial zone follows the order: Zn > Pb > Cu > Cr > Co > Cd. Residential high traffic and low traffic zones revealed the same trend as Cd < Co < Cr < Pb < Cu < Zn. Relatively strong positive correlation between the heavy metals at ρ < 0.05, such as Zn versus Cu (r = 0.79) and Co versus Cu (r = 0.77), was observed. The results of the study suggest that tree bark samples could potentially serve as bioindicators for Cu, Pb, Zn, Cr, and possibly Co and Cd. Furthermore, interspecies variation of heavy metal concentrations in plants barks is recommended. PMID:26605104

Effectiveness of work zone intelligent transportation systems.

DOT National Transportation Integrated Search

2013-12-01

In the last decade, Intelligent Transportation Systems (ITS) have increasingly been deployed in work zones by state departments of transportation. Also known as smart work zone systems they improve traffic operations and safety by providing real-time...

Temporary traffic control handbook, 2016 edition.

DOT National Transportation Integrated Search

2016-01-01

This handbook provides a broad, easy to understand : reference for temporary traffic control in work zones, : addressing the safe and efficient accommodation of all road : users: motorists, bicyclists, pedestrians, and those with special : needs. Whe...

Impacts of high resolution data on traveler compliance levels in emergency evacuation simulations

DOE PAGES

Lu, Wei; Han, Lee D.; Liu, Cheng; ...

2016-05-05

In this article, we conducted a comparison study of evacuation assignment based on Traffic Analysis Zones (TAZ) and high resolution LandScan USA Population Cells (LPC) with detailed real world roads network. A platform for evacuation modeling built on high resolution population distribution data and activity-based microscopic traffic simulation was proposed. This platform can be extended to any cities in the world. The results indicated that evacuee compliance behavior affects evacuation efficiency with traditional TAZ assignment, but it did not significantly compromise the performance with high resolution LPC assignment. The TAZ assignment also underestimated the real travel time during evacuation. Thismore » suggests that high data resolution can improve the accuracy of traffic modeling and simulation. The evacuation manager should consider more diverse assignment during emergency evacuation to avoid congestions.« less

[Evaluation of land resources carrying capacity of development zone based on planning environment impact assessment].

PubMed

Fu, Shi-Feng; Zhang, Ping; Jiang, Jin-Long

2012-02-01

Assessment of land resources carrying capacity is the key point of planning environment impact assessment and the main foundation to determine whether the planning could be implemented or not. With the help of the space analysis function of Geographic Information System, and selecting altitude, slope, land use type, distance from resident land, distance from main traffic roads, and distance from environmentally sensitive area as the sensitive factors, a comprehensive assessment on the ecological sensitivity and its spatial distribution in Zhangzhou Merchants Economic and Technological Development Zone, Fujian Province of East China was conducted, and the assessment results were combined with the planning land layout diagram for the ecological suitability analysis. In the Development Zone, 84.0% of resident land, 93.1% of industrial land, 86.0% of traffic land, and 76. 0% of other constructive lands in planning were located in insensitive and gently sensitive areas, and thus, the implement of the land use planning generally had little impact on the ecological environment, and the land resources in the planning area was able to meet the land use demand. The assessment of the population carrying capacity with ecological land as the limiting factor indicated that in considering the highly sensitive area and 60% of the moderately sensitive area as ecological land, the population within the Zone in the planning could reach 240000, and the available land area per capita could be 134.0 m2. Such a planned population scale is appropriate, according to the related standards of constructive land.

23 CFR 630.1006 - Work zone safety and mobility policy.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Work zone safety and mobility policy. 630.1006 Section 630.1006 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1006 Work zone safety and mobility...

23 CFR 630.1006 - Work zone safety and mobility policy.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Work zone safety and mobility policy. 630.1006 Section 630.1006 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1006 Work zone safety and mobility...

23 CFR 630.1006 - Work zone safety and mobility policy.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Work zone safety and mobility policy. 630.1006 Section 630.1006 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1006 Work zone safety and mobility...

23 CFR 630.1006 - Work zone safety and mobility policy.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Work zone safety and mobility policy. 630.1006 Section 630.1006 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1006 Work zone safety and mobility...

Incorporating twitter-based human activity information in spatial analysis of crashes in urban areas.

PubMed

Bao, Jie; Liu, Pan; Yu, Hao; Xu, Chengcheng

2017-09-01

The primary objective of this study was to investigate how to incorporate human activity information in spatial analysis of crashes in urban areas using Twitter check-in data. This study used the data collected from the City of Los Angeles in the United States to illustrate the procedure. The following five types of data were collected: crash data, human activity data, traditional traffic exposure variables, road network attributes and social-demographic data. A web crawler by Python was developed to collect the venue type information from the Twitter check-in data automatically. The human activities were classified into seven categories by the obtained venue types. The collected data were aggregated into 896 Traffic Analysis Zones (TAZ). Geographically weighted regression (GWR) models were developed to establish a relationship between the crash counts reported in a TAZ and various contributing factors. Comparative analyses were conducted to compare the performance of GWR models which considered traditional traffic exposure variables only, Twitter-based human activity variables only, and both traditional traffic exposure and Twitter-based human activity variables. The model specification results suggested that human activity variables significantly affected the crash counts in a TAZ. The results of comparative analyses suggested that the models which considered both traditional traffic exposure and human activity variables had the best goodness-of-fit in terms of the highest R 2 and lowest AICc values. The finding seems to confirm the benefits of incorporating human activity information in spatial analysis of crashes using Twitter check-in data. Copyright © 2017 Elsevier Ltd. All rights reserved.

Guidelines for developing transportation management plans in Virginia.

DOT National Transportation Integrated Search

2005-01-01

A transportation management plan (TMP) is a comprehensive program of traffic control, communication, operation, and demand management strategies designed to maintain acceptable levels of traffic flow in work zones. A systematic procedure and/or check...

23 CFR 630.1110 - Maintenance of temporary traffic control devices.

Code of Federal Regulations, 2013 CFR

2013-04-01

... of Transportation “Quality Standards for Work Zone Traffic Control Devices” is available online at... Unacceptable” is available online at http://www.dot.state.mn.us/trafficeng/otepubl/fieldmanual2007/FM-2007...

23 CFR 630.1110 - Maintenance of temporary traffic control devices.

Code of Federal Regulations, 2012 CFR

2012-04-01

... of Transportation “Quality Standards for Work Zone Traffic Control Devices” is available online at... Unacceptable” is available online at http://www.dot.state.mn.us/trafficeng/otepubl/fieldmanual2007/FM-2007...

23 CFR 630.1110 - Maintenance of temporary traffic control devices.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of Transportation “Quality Standards for Work Zone Traffic Control Devices” is available online at... Unacceptable” is available online at http://www.dot.state.mn.us/trafficeng/otepubl/fieldmanual2007/FM-2007...

23 CFR 630.1110 - Maintenance of temporary traffic control devices.

Code of Federal Regulations, 2014 CFR

2014-04-01

... of Transportation “Quality Standards for Work Zone Traffic Control Devices” is available online at... Unacceptable” is available online at http://www.dot.state.mn.us/trafficeng/otepubl/fieldmanual2007/FM-2007...

Beach disturbance caused by off-road vehicles (ORVs) on sandy shores: relationship with traffic volumes and a new method to quantify impacts using image-based data acquisition and analysis.

PubMed

Schlacher, Thomas A; Morrison, Jennifer M

2008-09-01

Vehicles cause environmental damage on sandy beaches, including physical displacement and compaction of the sediment. Such physical habitat disturbance provides a relatively simple indicator of ORV-related impacts that is potentially useful in monitoring the efficacy of beach traffic management interventions; such interventions also require data on the relationship between traffic volumes and the resulting levels of impact. Here we determined how the extent of beach disturbance is linked to traffic volumes and tested the utility of image-based data acquisition to monitor beach surfaces. Experimental traffic application resulted in disturbance effects ranging from 15% of the intertidal zone being rutted after 10 vehicle passes to 85% after 100 passes. A new camera platform, specifically designed for beach surveys, was field tested and the resulting image-based data compared with traditional line-intercept methods and in situ measurements using quadrats. All techniques gave similar results in terms of quantifying the relationship between traffic intensity and beach disturbance. However, the physical, in situ measurements, using quadrats, generally produced higher (+4.68%) estimates than photos taken with the camera platform coupled with off-site image analysis. Image-based methods can be more costly, but in politically and socially sensitive monitoring applications, such as ORV use on sandy beaches, they are superior in providing unbiased and permanent records of environmental conditions in relation to anthropogenic pressures.

Oregon Department of Transportation research leader : fall 2008.

DOT National Transportation Integrated Search

2008-01-01

The newsletter includes: : 1) To ensure safe travel through construction work zones, Traffic Control Plans (TCPs) are developed to communicate required traffic control measures to the construction team. The quality of the design and implementation of...

Estimation of traffic impacts at work zones : state of the practice.

DOT National Transportation Integrated Search

2006-01-01

Assessing the safety and mobility impacts of work zones across the project development phases of road construction and maintenance projects is an emphasis area of the Federal Highway Administration's Final Rule on Work Zone Safety and Mobility1 (Fina...

78 FR 71546 - Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... 1625-AA00 Safety Zone; Belt Parkway Bridge Construction, Gerritsen Inlet, Brooklyn, NY AGENCY: Coast... safety zone on the navigable waters of Gerritsen Inlet surrounding the Belt Parkway Bridge. This proposed rule would allow the Coast Guard to prohibit all vessel traffic through the safety zone during bridge...

33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

Code of Federal Regulations, 2010 CFR

2010-07-01

....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

Code of Federal Regulations, 2011 CFR

2011-07-01

....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

Code of Federal Regulations, 2012 CFR

2012-07-01

....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

Code of Federal Regulations, 2014 CFR

2014-07-01

....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

33 CFR 167.452 - In the Santa Barbara Channel: Between Point Conception and Point Arguello.

Code of Federal Regulations, 2013 CFR

2013-07-01

....452 In the Santa Barbara Channel: Between Point Conception and Point Arguello. (a) A separation zone... 120°30.16′ W. 34°18.90′ N 120°30.96′ W. 34°25.70′ N 120°51.81′ W. 34°23.75′ N 120°52.51′ W. (b) A traffic lane for westbound traffic is established between the separation zone and a line connecting the...

Guidelines for developing traffic incident management plans for work zones

DOT National Transportation Integrated Search

2003-09-01

The Colorado Department of Transportation (CDOT) has led the development of a number of traffic incident management plans and programs throughout the state. These programs address procedural and coordination aspects of managing unplanned events on th...

Evaluation of automated flagger assistance devices : interim report.

DOT National Transportation Integrated Search

2017-08-01

Flagger safety is an important issue in work zones due to the proximity of the flagger to traffic. Some strategies for improving flagger safety include slowing down approaching vehicles or removing flaggers from the immediate vicinity of traffic. The...

Work zone safety : physical and behavioral barriers in accident prevention.

DOT National Transportation Integrated Search

2014-05-01

This report discusses the usefulness of creating a work zone traffic safety culture as a methodology to improve the overall : safety of both work zone personnel and the traveling public in Missouri. As part of this research, the existing MoDOT : Work...

Work zone safety : physical and behavioral barriers in accident prevention.

DOT National Transportation Integrated Search

2014-05-01

This report discusses the usefulness of creating a work zone traffic safety culture as a methodology to improve the overall : safety of both work zone personnel and the traveling public in Missouri. As part of this research, the existing MoDOT : w : ...

Demonstration of automated speed enforcement in school zones in Portland, Oregon

DOT National Transportation Integrated Search

2006-02-01

The use of Automated Speed Enforcement (ASE) to reduce traffic speeds in school zones was demonstrated at five neighborhood schools in Portland, OR, during a two-month period. ASE was deployed at each demonstration school zone an average of two to th...

Identifying MMORPG Bots: A Traffic Analysis Approach

NASA Astrophysics Data System (ADS)

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

2008-12-01

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

Determination of traffic control device selection for nighttime maintenance of traffic.

DOT National Transportation Integrated Search

2010-01-01

Each year more than 700 fatalities occur nationally due to vehicular accidents within work zones. : [1] New developments and technologies have paved the way for the creation of diamond grade : sheeting, a new, more retroreflective sheeting. Research ...

Development of an interactive GIS based work zone traffic control tool.

DOT National Transportation Integrated Search

2013-08-01

The purpose of this study was to include consideration for intersections into the previously created GIS traffic control planning tool. Available data for making intersection control calculations were collected and integrated into the design of the t...

Traffic control and work zone safety for high volume roads.

DOT National Transportation Integrated Search

2012-07-01

The Manual on Uniform Traffic Control Devices (MUTCD) predominantly addresses work performed : along the centerline of roadways and low-speed roads. This work does not apply to the majority of : situations encountered by New Jersey Department of Tran...

Integrated capabilities in heavy vehicles : human factors research needs

DOT National Transportation Integrated Search

2003-10-09

The Full Road Closure method uses facility closure and total traffic diversion, which may be for one direction or bi-directional traffic flow, to accelerate construction and reduce the negative impacts of work zones. With good planning, interagency c...

Evaluation of the ADAPTIR System for Work Zone Traffic Control

DOT National Transportation Integrated Search

1999-11-01

The ADAPTIR system (Automated Data Acquisition and Processing of Traffic Information in Real Time) uses variable message signs (VMS) equipped with radar units, along with a software program to interpret the data, to display appropriate warning and ad...

Implementing speed reductions at specific interstate work zones from 65 mph to 35 mph : final report.

DOT National Transportation Integrated Search

2013-02-01

Interstate preservation projects are commonly conducted at night and often require working in close proximity to ongoing traffic. Vehicle speed and speed variability in work zones is inextricably connected to the work zone design and the selected tra...

Evaluation of technology-enhanced flagger devices : focus group and survey studies in Kansas.

DOT National Transportation Integrated Search

2009-04-01

Flagger-controlled work zones, by their very nature tend to utilize fewer traffic control measures than other work zones. Often these work zones are in place for only a short duration of time, so adding signing or positive protection beyond the minim...

Near-Road Exposure and Impact of Air Pollution on Allergic Diseases in Elementary School Children: A Cross-Sectional Study

PubMed Central

Kim, Ho Hyun; Lee, Chung Soo; Yu, Seung Do; Lee, Jung Sub; Chang, Jun Young; Jeon, Jun Min; Son, Hye Rim; Park, Chan Jung; Shin, Dong Chun

2016-01-01

Purpose The study aims to classify schools based on traffic pollutants and their complex sources, to assess the environment, to determine the state of allergic diseases among students using the International Study of Asthma and Allergies in children (ISAAC) questionnaire, and to assess their connection to air pollutants. Materials and Methods A total of seven schools were divided into three categories according to the characteristics of their surrounding environments: three schools in traffic-related zones, two schools in complex source zones I (urban), and two schools in complex source zones II (industrial complex). ISAAC questionnaires were administered and the 4404 completed questionnaires were analyzed. Results The frequency of asthma treatment during the past 12 months showed a significant increase (p<0.05) with exposure to NO2 [1.67, 95% confidence intervals (CIs) 1.03–2.71] in the complex source zones. The frequency of allergic rhinitis treatment during the past 12 months increased significantly with exposure to Black Carbon (1.60, 95% CIs 1.36–1.90) (p<0.001), SO2 (1.09, 95% CIs 1.01–1.17) (p<0.05), NO2 (1.18, 95% CIs 1.07–1.30) (p<0.01) for all subjects. Conclusion In terms of supporting children's health, care, and prevention related to major spaces for children, such as school zones, spaces used in coming to and leaving school, playgrounds, and classrooms are essential to ensuring not only the safety of children from traffic accidents but also their protection from local traffic pollutants and various hazardous environmental factors. PMID:26996571

Multi-level hot zone identification for pedestrian safety.

PubMed

Lee, Jaeyoung; Abdel-Aty, Mohamed; Choi, Keechoo; Huang, Helai

2015-03-01

According to the National Highway Traffic Safety Administration (NHTSA), while fatalities from traffic crashes have decreased, the proportion of pedestrian fatalities has steadily increased from 11% to 14% over the past decade. This study aims at identifying two zonal levels factors. The first is to identify hot zones at which pedestrian crashes occurs, while the second are zones where crash-involved pedestrians came from. Bayesian Poisson lognormal simultaneous equation spatial error model (BPLSESEM) was estimated and revealed significant factors for the two target variables. Then, PSIs (potential for safety improvements) were computed using the model. Subsequently, a novel hot zone identification method was suggested to combine both hot zones from where vulnerable pedestrians originated with hot zones where many pedestrian crashes occur. For the former zones, targeted safety education and awareness campaigns can be provided as countermeasures whereas area-wide engineering treatments and enforcement may be effective safety treatments for the latter ones. Thus, it is expected that practitioners are able to suggest appropriate safety treatments for pedestrian crashes using the method and results from this study. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach.

PubMed

Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

2017-06-01

Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach's alpha of 75%. Data was analyzed using the decision Delphi technique. GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information.

Addressing work zone traffic safety issues in Arizona.

DOT National Transportation Integrated Search

2017-03-01

The occurrence of work zone crashes is expected to increase in Arizona with the Arizona Department of Transportations (ADOTs) shifted emphasis from constructing new roadways to preserving existing facilities. Identifying factors that contribute...

Synthesis of work-zone performance measures.

DOT National Transportation Integrated Search

2013-09-01

The main objective of this synthesis was to identify and summarize how agencies collect, analyze, and report different work-zone : traffic-performance measures, which include exposure, mobility, and safety measures. The researchers also examined comm...

[Transfer characteristic and source identification of soil heavy metals from water-level-fluctuating zone along Xiangxi River, three-Gorges Reservoir area].

PubMed

Xu, Tao; Wang, Fei; Guo, Qiang; Nie, Xiao-Qian; Huang, Ying-Ping; Chen, Jun

2014-04-01

Transfer characteristics of heavy metals and their evaluation of potential risk were studied based on determining concentration of heavy metal in soils from water-level-fluctuating zone (altitude:145-175 m) and bank (altitude: 175-185 m) along Xiangxi River, Three Gorges Reservoir area. Factor analysis-multiple linear regression (FA-MLR) was employed for heavy metal source identification and source apportionment. Results demonstrate that, during exposing season, the concentration of soil heavy metals in water-level-fluctuation zone and bank showed the variation, and the concentration of soil heavy metals reduced in shallow soil, but increased in deep soil at water-level-fluctuation zone. However, the concentration of soil heavy metals reduced in both shallow and deep soil at bank during the same period. According to the geoaccumulation index,the pollution extent of heavy metals followed the order: Cd > Pb > Cu > Cr, Cd is the primary pollutant. FA and FA-MLR reveal that in soils from water-level-fluctuation zone, 75.60% of Pb originates from traffic, 62.03% of Cd is from agriculture, 64.71% of Cu and 75.36% of Cr are from natural rock. In soils from bank, 82.26% of Pb originates from traffic, 68.63% of Cd is from agriculture, 65.72% of Cu and 69.33% of Cr are from natural rock. In conclusion, FA-MLR can successfully identify source of heavy metal and compute source apportionment of heavy metals, meanwhile the transfer characteristic is revealed. All these information can be a reference for heavy metal pollution control.

Port Needs Study (Vessel Traffic Services Benefits) : Volume 2. Appendices, Part 1.

DOT National Transportation Integrated Search

1991-08-01

Volume II focuses on organization and presentation of information for each individual study zone. It contains the appendix tables of input data, output statistics and the documentation of the candidate Vessel Traffic Service (VTS) Design by NavCom Sy...

Safe and effective speed reductions for freeway work zones phase 2.

DOT National Transportation Integrated Search

2014-09-01

Freeway preservation projects typically require construction workers to conduct their : work in close proximity to ongoing traffic and often reduce traffic flow to a single lane while work is : undertaken in an adjacent lane. Due to the short-term na...

Port Needs Study (Vessel Traffic Services Benefits) : Volume 2. Appendices, Part 2.

DOT National Transportation Integrated Search

1991-01-01

Volume II focuses on organization and presentation of information for each individual study zone. It contains the appendix tables of input data, output statistics and the documentation of the candidate Vessel Traffic Services (VTS) Design by NavCom S...

14 CFR 99.41 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false General. 99.41 Section 99.41 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

Dilemma zone protection and signal coordination at closely-spaced high-speed intersections : final report, November 2001.

DOT National Transportation Integrated Search

2001-11-01

A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is gener...

Dilemma zone protection and signal coordination at closely-spaced high-speed intersections : executive summary, November 2001.

DOT National Transportation Integrated Search

2001-11-01

A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is gener...

Reduction of speed in work zones using ITS DMS instant feedback to drivers : vehicle speed versus traffic fine.

DOT National Transportation Integrated Search

2014-08-01

Accidents in work zones produced 17 fatalities in Arizona and 840 fatalities and over 40,000 injuries : nationally in 2009. Motorists nationwide can expect to drive through one active work zone for every 100 : miles driven on the National Highway Sys...

Implementing speed reductions at specific interstate work zones from 65 mph to 35 mph : appendices to final report.

DOT National Transportation Integrated Search

2013-02-01

Interstate preservation projects are commonly conducted at night and often require working in close proximity to ongoing traffic. Vehicle speed and speed variability in work zones is inextricably connected to the work zone design and the selected tra...

Traffic incident management in construction and maintenance work zones.

DOT National Transportation Integrated Search

2009-01-01

In 2004, the Federal Highway Administration published updated rules governing work zone safety and mobility; all highway construction and maintenance projects using federal-aid highway funds are required to develop transportation management plans (TM...

Research notes : nighttime illumination of work zone flaggers.

DOT National Transportation Integrated Search

2006-05-01

As daytime traffic demands increase, nighttime construction and maintenance work is becoming more prevalent. The effective and efficient illumination of flaggers in these work zones is a significant concern . Insufficient light levels, disabling glar...

Speeds in school zones.

DOT National Transportation Integrated Search

2009-02-01

School speed zones are frequently requested traffic controls for school areas, based on the common belief : that if the transportation agency would only install a reduced speed limit, then drivers would no longer : speed through the area. This resear...

Investigation of accidents within construction zones in Louisiana.

DOT National Transportation Integrated Search

1981-07-01

This investigation is to analyze construction and maintenance work zone accidents by reviewing accident data to determine if deficiencies exist and recommend possible corrective measures for future traffic control applications. To accomplish this, a ...

Evaluation of warning lights on maintenance of traffic devices and development of possible alternatives : [summary].

DOT National Transportation Integrated Search

2013-01-01

Orange plastic drums are common on Florida roadways, warning motorists and guiding them safely through work zones. The orange color is mandated by the Manual on Uniform Traffic Control Devices, which also requires that drums bear retroreflective whit...

Integrated risk management for improving internal traffic control, work-zone safety, and mobility during major construction.

DOT National Transportation Integrated Search

2012-10-01

Highway construction is among the most dangerous industries in the US. Internal traffic control design, along with how construction : equipment and vehicles interact with the traveling public, have a significant effect on how safe a highway construct...

14 CFR 99.47 - Guam ADIZ.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Guam ADIZ. 99.47 Section 99.47 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC Designated Air Defense Identification Zones § 99...

Populations potentially exposed to traffic-related air pollution in seven world cities.

PubMed

Su, Jason G; Apte, Joshua S; Lipsitt, Jonah; Garcia-Gonzales, Diane A; Beckerman, Bernardo S; de Nazelle, Audrey; Texcalac-Sangrador, José Luis; Jerrett, Michael

2015-05-01

Traffic-related air pollution (TRAP) likely exerts a large burden of disease globally, and in many places, traffic is increasing dramatically. The impact, however, of urban form on the portion of population potentially exposed to TRAP remains poorly understood. In this study, we estimate portions of population potentially exposed to TRAP across seven global cities of various urban forms. Data on population distributions and road networks were collected from the best available sources in each city and from remote sensing analysis. Using spatial mapping techniques, we first overlaid road buffers onto population data to estimate the portions of population potentially exposed for four plausible impact zones. Based on a most likely scenario with impacts from highways up to 300meters and major roadways up to 50meters, we identified that the portions of population potentially exposed for the seven cities ranged from 23 to 96%. High-income North American cities had the lowest potential exposure portions, while those in Europe had the highest. Second, we adjusted exposure zone concentration levels based on a literature suggested multiplier for each city using corresponding background concentrations. Though Beijing and Mexico City did not have the highest portion of population exposure, those in their exposure zones had the highest levels of exposure. For all seven cities, the portion of population potentially exposed was positively correlated with roadway density and, to a lesser extent, with population density. These analyses suggest that urban form may influence the portion of population exposed to TRAP and vehicle emissions and other factors may influence the exposure levels. Greater understanding of urban form and other factors influencing potential exposure to TRAP may help inform interventions that protect public health. Copyright © 2014 Elsevier Ltd. All rights reserved.

Air quality improvements following implementation of Lisbon's Low Emission Zone

NASA Astrophysics Data System (ADS)

Ferreira, F.; Gomes, P.; Tente, H.; Carvalho, A. C.; Pereira, P.; Monjardino, J.

2015-12-01

Air pollution levels within Lisbon city limits have been exceeding the limit values established in European Union and national legislation since 2001, with the most problematic cases related to the levels of fine particles (PM10) and nitrogen dioxide (NO2), mainly originated by road traffic. With the objective of answering this public health issue, an Air Quality Action Plan was developed in 2006 and the respective Enforcement Plan was published in 2009. From the overall strategy, one of the major measures presented in this strategy was the creation of a Low Emission Zone (LEZ) in Lisbon, which has been operating since July 2011. Implemented at different stages it has progressively expanded its area, including more vehicle types and adopting more stringent requirements in terms of minimum emission standards (currently LEZ phase 2 with EURO 2 in the city center - zone 1 and EURO 1 in the rest of the LEZ area - zone 2). At the same time the road axis comprised of Marquês de Pombal square and Avenida da Liberdade was subjected to profound changes in its traffic circulation model, reducing road traffic volumes. The analysis of the air quality data before and after the LEZ phase 2 has shown positive evolution when comparing the period between 2011 (before measures) and 2013 (after measures). In 2013, there was a reduction in PM10 annual average concentration of 23% and NO2 annual average concentrations of 12%, compared with the year 2011. Although PM10 reductions were more significant inside the LEZ area, the same was not valid for NO2, suggesting that the implementation of these measures was not as effective in reducing NO2 levels as shown by results in other cities like Berlin and London. The results from road traffic characterization indicate a relevant effect on fleet renewal with an overall decrease in the relative weight of pre-EURO 2 vehicles in 2012/2013, compared with data from 2011. An important increase in the share of EURO 4 and EURO 5 vehicles was also observed. Our conclusions show that the level of ambition is relevant for the observed effects. Therefore, stricter restriction standards should be enforced in the future stages of the Lisbon LEZ in conjunction with a higher effort and investment on LEZ enforcement.

Crashworthiness testing of a portable maintenance work-zone barrier.

DOT National Transportation Integrated Search

2008-12-01

Barrier and shadow vehicles generally provide Caltrans maintenance workers protection from errant vehicles entering the work zones, from the upstream direction of traffic flow. This type of protection does not protect workers from vehicles entering t...

Vehicle accidents in highway work zones.

DOT National Transportation Integrated Search

1981-01-01

The objective of this study was to determine the magnitude and characteristics of safety problems, in terms of reported accidents, that are associated with moving vehicular traffic around and through highway work zones. This was accomplished by exami...

Work zone positive protection guidelines for Idaho.

DOT National Transportation Integrated Search

2014-12-01

The Code of Federal Regulation (CFR) Title 23 Part 630 Subpart K - Temporary Traffic Control (630.1102630.1110) rule states : that positive protection shall be considered where work zone conditions place workers at increased risk from motorized : ...

Evaluation of mobile work zone alarm systems.

DOT National Transportation Integrated Search

2014-06-01

Maintenance of highways often involves mobile work zones for various types of low speed moving operations such as : striping and sweeping. The speed differential between the moving operation and traffic, and the increasing problem of : distracted dri...

Violence in public transportation: an approach based on spatial analysis.

PubMed

Sousa, Daiane Castro Bittencourt de; Pitombo, Cira Souza; Rocha, Samille Santos; Salgueiro, Ana Rita; Delgado, Juan Pedro Moreno

2017-12-11

To carry out a spatial analysis of the occurrence of acts of violence (specifically robberies) in public transportation, identifying the regions of greater incidence, using geostatistics, and possible causes with the aid of a multicriteria analysis in the Geographic Information System. The unit of analysis is the traffic analysis zone of the survey named Origem-Destino, carried out in Salvador, state of Bahia, in 2013. The robberies recorded by the Department of Public Security of Bahia in 2013 were located and made compatible with the limits of the traffic analysis zones and, later, associated with the respective centroids. After determining the regions with the highest probability of robbery, we carried out a geographic analysis of the possible causes in the region with the highest robbery potential, considering the factors analyzed using a multicriteria analysis in a Geographic Information System environment. The execution of the two steps of this study allowed us to identify areas corresponding to the greater probability of occurrence of robberies in public transportation. In addition, the three most vulnerable road sections (Estrada da Liberdade, Rua Pero Vaz, and Avenida General San Martin) were identified in these areas. In these sections, the factors that most contribute with the potential for robbery in buses are: F1 - proximity to places that facilitate escape, F3 - great movement of persons, and F2 - absence of policing, respectively. Indicator Kriging (geostatistical estimation) can be used to construct a spatial probability surface, which can be a useful tool for the implementation of public policies. The multicriteria analysis in the Geographic Information System environment allowed us to understand the spatial factors related to the phenomenon under analysis.

Violence in public transportation: an approach based on spatial analysis

PubMed Central

de Sousa, Daiane Castro Bittencourt; Pitombo, Cira Souza; Rocha, Samille Santos; Salgueiro, Ana Rita; Delgado, Juan Pedro Moreno

2017-01-01

ABSTRACT OBJECTIVE To carry out a spatial analysis of the occurrence of acts of violence (specifically robberies) in public transportation, identifying the regions of greater incidence, using geostatistics, and possible causes with the aid of a multicriteria analysis in the Geographic Information System. METHODS The unit of analysis is the traffic analysis zone of the survey named Origem-Destino, carried out in Salvador, state of Bahia, in 2013. The robberies recorded by the Department of Public Security of Bahia in 2013 were located and made compatible with the limits of the traffic analysis zones and, later, associated with the respective centroids. After determining the regions with the highest probability of robbery, we carried out a geographic analysis of the possible causes in the region with the highest robbery potential, considering the factors analyzed using a multicriteria analysis in a Geographic Information System environment. RESULTS The execution of the two steps of this study allowed us to identify areas corresponding to the greater probability of occurrence of robberies in public transportation. In addition, the three most vulnerable road sections (Estrada da Liberdade, Rua Pero Vaz, and Avenida General San Martin) were identified in these areas. In these sections, the factors that most contribute with the potential for robbery in buses are: F1 - proximity to places that facilitate escape, F3 - great movement of persons, and F2 - absence of policing, respectively. CONCLUSIONS Indicator Kriging (geostatistical estimation) can be used to construct a spatial probability surface, which can be a useful tool for the implementation of public policies. The multicriteria analysis in the Geographic Information System environment allowed us to understand the spatial factors related to the phenomenon under analysis. PMID:29236883

Non-federal applications of the Highway Performance Monitoring System

DOT National Transportation Integrated Search

1978-05-01

The report contains an experimental design to evaluate methods of providing safe and expeditious movement of traffic through or around construction and maintenance zones while providing safety for workers in these zones. Two types of construction/mai...

Variable Speed Limit (VSL) - Best Management Practice [Summary

DOT National Transportation Integrated Search

2012-01-01

In variable speed limit (VSL) zones, the speed : limit changes in response to traffic congestion, : adverse weather, or road conditions. VSL zones are : often highly automated and have been employed : successfully in several U.S. and European : locat...

Improving work-zone delineation on limited access highways.

DOT National Transportation Integrated Search

1989-01-01

The purpose of this study was to investigate vehicle guidance through work zones by evaluating the effectiveness of two primary components of traffic control relative to delineation. First, a comparison of the steady-burn lights presently used on top...

Studies to determine the effectiveness of longitudinal channelizing devices in work zones.

DOT National Transportation Integrated Search

2011-01-01

This report describes the methodology and results of analyses performed to determine whether the following longitudinal : channelizing device (LCD) applications improve the traffic safety and operations of work zones relative to the use of standard :...

Vehicle accidents at maintenance and utility work zones.

DOT National Transportation Integrated Search

1978-01-01

The objective of this study was to determine the magnitude and characteristics of safety problems, in terms of reported accidents, that are associated with moving vehicular traffic around and through highway maintenance and utility work zones. This w...

Development of an NCHRP report 350 TL-3 New Jersey shape 50-inch portable concrete barrier : final report, June 2006.

DOT National Transportation Integrated Search

2006-06-01

For roadside work-zones in areas that have opposing traffic flow, safety is enhanced if the temporary barriers incorporate a "glare-shield" that blocks headlight glare from opposing traffic. Currently-available 32-inch portable concrete barriers requ...

Evaluation of chevron patterns for use on traffic control devices in street and highway work zones.

DOT National Transportation Integrated Search

1980-01-01

The chevron pattern consists of alternate orange and white stripes that form an arrow pointing in the direction in which traffic is being diverted. The objectives of this research were (1) to select the most effective design for the chevron pattern, ...

Heavy vehicle performance during recovery from forced-flow urban freeway conditions due to incidents, work zones and recurring congestion.

DOT National Transportation Integrated Search

2013-12-01

Information contained in the Highway Capacity Manual on the influence heavy vehicles have on freeway traffic : operations has been based on few field data collection efforts and relied mostly on traffic simulation efforts. In the : 2010 Manual heavy ...

Designing with Traffic Safety in Mind.

ERIC Educational Resources Information Center

Matthews, John

1998-01-01

Provides an example of how one county public school system was able to minimize traffic accidents and increase safety around its schools. Illustrations are provided of safer bus loading zones, pedestrian walkways and sidewalks, staff parking, and acceptable methods for staging buses. A checklist for school driveway design concludes the article.…

Geographic Information System (GIS) capabilities in traffic accident information management: a qualitative approach

PubMed Central

Ahmadi, Maryam; Valinejadi, Ali; Goodarzi, Afshin; Safari, Ameneh; Hemmat, Morteza; Majdabadi, Hesamedin Askari; Mohammadi, Ali

2017-01-01

Background Traffic accidents are one of the more important national and international issues, and their consequences are important for the political, economical, and social level in a country. Management of traffic accident information requires information systems with analytical and accessibility capabilities to spatial and descriptive data. Objective The aim of this study was to determine the capabilities of a Geographic Information System (GIS) in management of traffic accident information. Methods This qualitative cross-sectional study was performed in 2016. In the first step, GIS capabilities were identified via literature retrieved from the Internet and based on the included criteria. Review of the literature was performed until data saturation was reached; a form was used to extract the capabilities. In the second step, study population were hospital managers, police, emergency, statisticians, and IT experts in trauma, emergency and police centers. Sampling was purposive. Data was collected using a questionnaire based on the first step data; validity and reliability were determined by content validity and Cronbach’s alpha of 75%. Data was analyzed using the decision Delphi technique. Results GIS capabilities were identified in ten categories and 64 sub-categories. Import and process of spatial and descriptive data and so, analysis of this data were the most important capabilities of GIS in traffic accident information management. Conclusion Storing and retrieving of descriptive and spatial data, providing statistical analysis in table, chart and zoning format, management of bad structure issues, determining the cost effectiveness of the decisions and prioritizing their implementation were the most important capabilities of GIS which can be efficient in the management of traffic accident information. PMID:28848627

Factors associated with NO2 and NOX concentration gradients near a highway

NASA Astrophysics Data System (ADS)

Richmond-Bryant, J.; Snyder, M. G.; Owen, R. C.; Kimbrough, S.

2018-02-01

The objective of this research is to learn how the near-road gradient, in which NO2 and NOX (NO + NO2) concentrations are elevated, varies with changes in meteorological and traffic variables. Measurements of NO2 and NOX were obtained east of I-15 in Las Vegas and fit to functions whose slopes (dCNO2/dx and dCNOX/dx, respectively) characterize the size of the near-road zone where NO2 and NOX concentrations from mobile sources on the highway are elevated. These metrics were used to learn about the near-road gradient by modeling dCNO2/dx and dCNOX/dx as functions of meteorological variables (e.g., wind direction, wind speed), traffic (vehicle count), NOX concentration upwind of the road, and O3 concentration at two fixed-site ambient monitors. Generalized additive models (GAM) were used to model dCNO2/dx and dCNOX/dx versus the independent variables because they allowed for nonlinearity of the variables being compared. When data from all wind directions were included in the analysis, variability in O3 concentration comprised the largest proportion of variability in dCNO2/dx, followed by variability in wind direction. In a second analysis constrained to winds from the west, variability in O3 concentration remained the largest contributor to variability in dCNO2/dx, but the relative contribution of variability in wind speed to variability in dCNO2/dx increased relative to its contribution for the all-wind analysis. When data from all wind directions were analyzed, variability in wind direction was by far the largest contributor to variability in dCNOX/dx, with smaller contributions from hour of day and upwind NOX concentration. When only winds from the west were analyzed, variability in upwind NOX concentration, wind speed, hour of day, and traffic count all were associated with variability in dCNOX/dx. Increases in O3 concentration were associated with increased magnitude near-road dCNO2/dx, possibly shrinking the zone of elevated concentrations occurring near roads. Wind direction parallel to the highway was also related to an increased magnitude of both dCNO2/dx and dCNOX/dx, again likely shrinking the zone of elevated concentrations occurring near roads. Wind direction perpendicular to the road decreased the magnitude of dCNO2/dx and dCNOX/dx and likely contributed to growth of the zone of elevated concentrations occurring near roads. Thus, variability in near-road concentrations is influenced by local meteorology and ambient O3 concentration.

Origin of fine dust in urban environmental zones--Evidence from element patterns received by dichotomous collection and INAA.

PubMed

Weckwerth, G

2010-10-01

In order to fulfil the EU-limitations of fine dust and traffic-produced gases Cologne installed 2008 one of the first German environmental zones, from which stepwise vehicles with too high emissions will be locked out. Verification of effectiveness and the research on further strategies to reduce fine dust are studied as promising applications of a method on discrimination of aerosol components from different origins (Weckwerth, 2001). New measurements in Cologne gave several implications on supports, especially in connection with traffic abrasion from brakes, tires and rails. Copyright 2010. Published by Elsevier Ltd.

Analysis of work zone rear-end crash risk for different vehicle-following patterns.

PubMed

Weng, Jinxian; Meng, Qiang; Yan, Xuedong

2014-11-01

This study evaluates rear-end crash risk associated with work zone operations for four different vehicle-following patterns: car-car, car-truck, truck-car and truck-truck. The deceleration rate to avoid the crash (DRAC) is adopted to measure work zone rear-end crash risk. Results show that the car-truck following pattern has the largest rear-end crash risk, followed by truck-truck, truck-car and car-car patterns. This implies that it is more likely for a car which is following a truck to be involved in a rear-end crash accident. The statistical test results further confirm that rear-end crash risk is statistically different between any two of the four patterns. We therefore develop a rear-end crash risk model for each vehicle-following pattern in order to examine the relationship between rear-end crash risk and its influencing factors, including lane position, the heavy vehicle percentage, lane traffic flow and work intensity which can be characterized by the number of lane reductions, the number of workers and the amount of equipment at the work zone site. The model results show that, for each pattern, there will be a greater rear-end crash risk in the following situations: (i) heavy work intensity; (ii) the lane adjacent to work zone; (iii) a higher proportion of heavy vehicles and (iv) greater traffic flow. However, the effects of these factors on rear-end crash risk are found to vary according to the vehicle-following patterns. Compared with the car-car pattern, lane position has less effect on rear-end crash risk in the car-truck pattern. The effect of work intensity on rear-end crash risk is also reduced in the truck-car pattern. Copyright © 2014 Elsevier Ltd. All rights reserved.

Seasonal Variability Study of the Tropospheric Zenithal Delay in the South America using regional Numerical Weather Prediction model

NASA Astrophysics Data System (ADS)

Sapucci, L. F.; Monico, J. G.; Machado, L. T.

2007-05-01

In 2010 a new navigation and administration system of the air traffic, denominated CNS-ATM (Communication Navigation Surveillance - Air Traffic Management) should be running operationally in South America. This new system will basically employ the positioning techniques by satellites to the management and air traffic control. However, the efficiency of this new system demands the knowledge of the behavior of the atmosphere, consequently, an appropriated Zenithal Tropospheric Delay (ZTD) modeling in a regional scale. The predictions of ZTD values from Numeric Weather Prediction (NWP), denominated here dynamic modeling, is an alternative to model the atmospheric gases effects in the radio-frequency signals in real time. Brazilian Center for Weather Forecasting and Climate Studies (CPTEC) of the National Institute for Space Research (INPE), jointly with researchers from UNESP (Sao Paulo State University), has generated operationally prediction of ZTD values to South America Continent (available in the electronic address http:satelite.cptec.inpe.br/htmldocs/ztd/zenithal.htm). The available regional version is obtained using ETA model (NWP model with horizontal resolution of 20 km and 42 levels in the vertical). The application of NWP permit assess the temporal and spatial variation of ZTD values, which is an important characteristic of this techniques. The aim of the present paper is to investigate the ZTD seasonal variability over South America continent. A variability analysis of the ZTD components [hydrostatic(ZHD) and wet(ZWD)] is also presented, as such as discussion of main factors that influence this variation in this region. The hydrostatic component variation is related with atmospheric pressure oscillation, which is influenced by relief and high pressure centers that prevail over different region of the South America continent. The wet component oscillation is due to the temperature and humidity variability, which is also influenced by relief and by synoptic events like: the penetration the cold front from Antarctic pole into the continent and occurrence of humidity convergence zones. In South America there are two main convergence zones that has strong influence in the troposphere variability, the ITCZ (Inter Tropical Convergence Zone) and the SACZ (South Atlantic Convergence Zone) zones. These convergence zones are characterized by an extensive precipitation band and high nebulosity almost stationary. The physical processes associated with these convergence zones present strong impacts in the variability of ZWD values. This work aims to contribute with ZTD modeling over South America continent using NWP to identify where and when the ZTD values present lower predictability in this region, and consequently, minimizing the error in the GNSS positioning that apply this technique.

Effects of Nautical Traffic and Noise on Foraging Patterns of Mediterranean Damselfish (Chromis chromis)

PubMed Central

Bracciali, Claudia; Campobello, Daniela; Giacoma, Cristina; Sarà, Gianluca

2012-01-01

Chromis chromis is a key species in the Mediterranean marine coastal ecosystems where, in summer, recreational boating and its associated noise overlap. Anthropogenic noise could induce behavioural modifications in marine organisms, thereby affecting population dynamics. In the case of an important species for the ecosystem like C. chromis, this could rebound on the community structure. Here, we measured nautical traffic during the summer of 2007 in a Southern Mediterranean Marine Protected Area (MPA) and simultaneously the feeding behaviour of C. chromis was video-recorded, within both the no-take A-zone and the B-zone where recreational use is allowed. Feeding frequencies, escape reaction and school density were analysed. C. chromis specimens were also collected from 2007 to 2008 to evaluate their physiological state using the Body Condition Index as a proxy of feeding efficiency. The MPA was more exploited by nautical tourism during holidays than on weekdays, particularly in the middle of the day. Greater traffic volume corresponded with lower feeding frequencies. The escape reaction was longer in duration (>1 min) when boat passed nearby, while moored boats did not induce an escape response. We found no differences in density between schools in the A- and B-zones and worse body conditions among those individuals inhabiting the B-zone in one area only. Overall, our findings revealed a significant modification of the daily foraging habits of C. chromis due to boat noise, which was slightly buffered by no-take zones established within the MPA. PMID:22792375

76 FR 37650 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake Tahoe Gaming... will enforce the safety zone for the annual Fourth of July Fireworks, South Lake Tahoe Gaming Alliance (Lights on the Lake Fireworks Display). This action is necessary to control vessel traffic and to ensure...

75 FR 56467 - Safety Zone; Ocean City Beachfront Air Show, Ocean City, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

...-AA00 Safety Zone; Ocean City Beachfront Air Show, Ocean City, NJ AGENCY: Coast Guard, DHS. ACTION... Atlantic Ocean, Ocean City, NJ. The temporary safety zone will restrict vessel traffic from a portion of the Atlantic Ocean during the Ocean City Beachfront Air Show, which is an aerial demonstration to be...

Analysis of rail welding methods for mine rail access with the use of modern technologies

NASA Astrophysics Data System (ADS)

Usoltsev, A. A.; Shevchenko, R. A.; Kozyrev, N. A.; Kriukov, R. E.; Shishkin, P. E.

2017-09-01

Welded joint zones are weak sections of the railway track for all traffic cases (in the case of high-speed traffic and heavy traffic). In the paper advantages and disadvantages of the basic ways of rails welding, which are widely used today, are considered: electrocontact and aluminothermic. Carefully selected mode of differentially thermally strengthened rails string will allow the process of correction after heat treatment to be minimized and internal residual compressive stresses to be kept. Particular attention should be paid to the method of rails welding, in which after rails welding during their cooling it is offered to perform quasi-isothermal exposure in the temperature range of fine structure formation by passing pulses of alternating electric current through the welded joint maintaining this temperature until the end of the transformation. The use of quasi-isothermal exposure at a temperature of 600 - 650 °C makes it possible to obtain a finely dispersed structure of the welded seam of rails without additional heat treatment.

Design of lane merges at rural freeway construction work zones.

DOT National Transportation Integrated Search

2012-10-01

Practices for the design and control of work zone traffic control configurations have evolved over time : to reflect safer and more efficient management practices. However, they are also recognized as areas : of frequent vehicle conflicts that can ca...

23 CFR 630.1014 - Implementation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1014 Implementation. Each State shall work in partnership with the FHWA in the implementation of its policies and procedures to improve work zone safety and...

23 CFR 630.1014 - Implementation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1014 Implementation. Each State shall work in partnership with the FHWA in the implementation of its policies and procedures to improve work zone safety and...

23 CFR 630.1002 - Purpose.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1002 Purpose. Work zones directly impact the safety and mobility of road users and highway workers. These safety and mobility impacts are exacerbated by an aging...

23 CFR 630.1014 - Implementation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1014 Implementation. Each State shall work in partnership with the FHWA in the implementation of its policies and procedures to improve work zone safety and...

23 CFR 630.1002 - Purpose.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1002 Purpose. Work zones directly impact the safety and mobility of road users and highway workers. These safety and mobility impacts are exacerbated by an aging...

23 CFR 630.1014 - Implementation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1014 Implementation. Each State shall work in partnership with the FHWA in the implementation of its policies and procedures to improve work zone safety and...

23 CFR 630.1002 - Purpose.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1002 Purpose. Work zones directly impact the safety and mobility of road users and highway workers. These safety and mobility impacts are exacerbated by an aging...

Minimizing traffic-related work zone crashes in Illinois.

DOT National Transportation Integrated Search

2013-04-01

This report presents the findings of a research project to study and develop recommendations to minimize work : zone crashes in Illinois. The objectives of this project were (1) to provide in-depth comprehensive review of the : latest literature on t...

Optimal design of work zone median crossovers.

DOT National Transportation Integrated Search

2010-09-01

The use of temporary median crossovers in work zones allows for the closure of one side of a multi-lane roadway while : maintaining two-way traffic on the opposite side. This process provides the ability for construction and maintenance crews : to co...

Evaluation of a mobile work zone barrier system : appendices.

DOT National Transportation Integrated Search

2013-08-01

A high percentage of highway maintenance activities and some construction activities are performed in a travel lane, median, or shoulder while the public travels by at relatively high speeds in very close proximity to the workers. Work zone traffic c...

Evaluation of a mobile work zone barrier system.

DOT National Transportation Integrated Search

2013-08-01

A high percentage of highway maintenance activities and some construction activities are performed in a travel lane, median, or shoulder while the public travels by at relatively high speeds in very close proximity to the workers. Work zone traffic c...

Work-zone traffic performance measures : tech transfer summary.

DOT National Transportation Integrated Search

2013-09-01

The Federal Highway Administration (FHWA) 2004 Work Zone Safety and Mobility Rule applies to all state and local government agencies that receive federal-aid highway funding after October 12, 2007. This rule was an update to the former regulation (23...

The employment of a spoken language computer applied to an air traffic control task.

NASA Technical Reports Server (NTRS)

Laveson, J. I.; Silver, C. A.

1972-01-01

Assessment of the merits of a limited spoken language (56 words) computer in a simulated air traffic control (ATC) task. An airport zone approximately 60 miles in diameter with a traffic flow simulation ranging from single-engine to commercial jet aircraft provided the workload for the controllers. This research determined that, under the circumstances of the experiments carried out, the use of a spoken-language computer would not improve the controller performance.

23 CFR 630.1008 - State-level processes and procedures.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 630.1008 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1008 State-level processes and... sustain their respective work zone safety and mobility policies. State-level processes and procedures...

23 CFR 630.1008 - State-level processes and procedures.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 630.1008 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1008 State-level processes and... sustain their respective work zone safety and mobility policies. State-level processes and procedures...

23 CFR 630.1008 - State-level processes and procedures.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 630.1008 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1008 State-level processes and... sustain their respective work zone safety and mobility policies. State-level processes and procedures...

78 FR 29094 - Safety Zone; Coronado Fourth of July Fireworks, Glorietta Bay; Coronado, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-17

... waterways, darkness punctuated by bright flashes of light and burning debris has the potential to result in...: The safety zone will only be in effect for one hour, late in the evening when vessel traffic is low...

An intelligent decision support system for work zone traffic management and planning.

DOT National Transportation Integrated Search

2004-01-01

Periodic resurfacing, rehabilitation, restoration, and reconstruction work is needed on the aging highway system in the state of Ohio to maintain a desired level of service for the traveling public. However, temporary work zones on highways disrupt t...

Developing a smartphone based warning system application to enhance the safety at work zones : final report.

DOT National Transportation Integrated Search

2016-05-01

Collisions in the work zone have always been a contributing factor to compromising safety on urban roadways. The National Highway Traffic Safety Administration (NHTSA) and the State Transportation Authorities have implemented many safety countermeasu...

Evaluation of the late merge work zone traffic control strategy.

DOT National Transportation Integrated Search

2004-01-01

Several alternative lane merge strategies have been proposed in recent years to process vehicles through work zone lane closures more safely and efficiently. Among these is the late merge. With the late merge, drivers are instructed to use all lanes ...

33 CFR 165.T09-0263 - Safety zone; Red River Safety Zone, Red River, MN.

Code of Federal Regulations, 2011 CFR

2011-07-01

... across latitude 46°20'00” N, including those portions of the river in Wilkin, Clay, Norman, Polk... designated on-scene representative. (2) This safety zone is closed to all vessel traffic, except as may be... vessel. The Captain of the Port Duluth or his designated on-scene representative may be contacted via VHF...

The impact of a major earthquake on the evacuation of the emergency planning zone of a nuclear power plant.

PubMed

Cohen, Rebecca; Weinisch, Kevin

2015-01-01

United States regulations require nuclear power plants (NPPs) to estimate the time needed to evacuate the emergency planning zone (EPZ, a circle with an approximate 10-mile radius centered at the NPP). These evacuation time estimate (ETE) studies are to be used by emergency personnel in the event of a radiological emergency. ETE studies are typically done using traffic simulation and evacuation models, based on traffic engineering algorithms that reflect congestion and delay. ETE studies are typically conducted assuming all evacuation routes are traversable. As witnessed in the Great East Japan Earthquake in March 2011, an earthquake and the ensuing tsunami can cause an incident at a NPP that requires an evacuation of the public. The earthquake and tsunami can also damage many of the available bridges and roadways and, therefore, impede evacuation and put people at risk of radiation exposure. This article presents a procedure, using traffic simulation and evacuation models, to estimate the impact on ETE due to bridge and roadway damage caused by a major earthquake, or similar hazardous event. The results of this analysis are used by emergency personnel to make protective action decisions that will minimize the exposure of radiation to the public. Additionally, the results allow emergency planners to ensure proper equipment and personnel are available for these types of events. Emergency plans are revised to ensure prompt response and recovery action during critical times.

Conflict Detection and Resolution for Future Air Transportation Management

NASA Technical Reports Server (NTRS)

Krozel, Jimmy; Peters, Mark E.; Hunter, George

1997-01-01

With a Free Flight policy, the emphasis for air traffic control is shifting from active control to passive air traffic management with a policy of intervention by exception. Aircraft will be allowed to fly user preferred routes, as long as safety Alert Zones are not violated. If there is a potential conflict, two (or more) aircraft must be able to arrive at a solution for conflict resolution without controller intervention. Thus, decision aid tools are needed in Free Flight to detect and resolve conflicts, and several problems must be solved to develop such tools. In this report, we analyze and solve problems of proximity management, conflict detection, and conflict resolution under a Free Flight policy. For proximity management, we establish a system based on Delaunay Triangulations of aircraft at constant flight levels. Such a system provides a means for analyzing the neighbor relationships between aircraft and the nearby free space around air traffic which can be utilized later in conflict resolution. For conflict detection, we perform both 2-dimensional and 3-dimensional analyses based on the penetration of the Protected Airspace Zone. Both deterministic and non-deterministic analyses are performed. We investigate several types of conflict warnings including tactical warnings prior to penetrating the Protected Airspace Zone, methods based on the reachability overlap of both aircraft, and conflict probability maps to establish strategic Alert Zones around aircraft.

Work zone safety analysis and modeling: a state-of-the-art review.

PubMed

Yang, Hong; Ozbay, Kaan; Ozturk, Ozgur; Xie, Kun

2015-01-01

Work zone safety is one of the top priorities for transportation agencies. In recent years, a considerable volume of research has sought to determine work zone crash characteristics and causal factors. Unlike other non-work zone-related safety studies (on both crash frequency and severity), there has not yet been a comprehensive review and assessment of methodological approaches for work zone safety. To address this deficit, this article aims to provide a comprehensive review of the existing extensive research efforts focused on work zone crash-related analysis and modeling, in the hopes of providing researchers and practitioners with a complete overview. Relevant literature published in the last 5 decades was retrieved from the National Work Zone Crash Information Clearinghouse and the Transport Research International Documentation database and other public digital libraries and search engines. Both peer-reviewed publications and research reports were obtained. Each study was carefully reviewed, and those that focused on either work zone crash data analysis or work zone safety modeling were identified. The most relevant studies are specifically examined and discussed in the article. The identified studies were carefully synthesized to understand the state of knowledge on work zone safety. Agreement and inconsistency regarding the characteristics of the work zone crashes discussed in the descriptive studies were summarized. Progress and issues about the current practices on work zone crash frequency and severity modeling are also explored and discussed. The challenges facing work zone safety research are then presented. The synthesis of the literature suggests that the presence of a work zone is likely to increase the crash rate. Crashes are not uniformly distributed within work zones and rear-end crashes are the most prevalent type of crashes in work zones. There was no across-the-board agreement among numerous papers reviewed on the relationship between work zone crashes and other factors such as time, weather, victim severity, traffic control devices, and facility types. Moreover, both work zone crash frequency and severity models still rely on relatively simple modeling techniques and approaches. In addition, work zone data limitations have caused a number of challenges in analyzing and modeling work zone safety. Additional efforts on data collection, developing a systematic data analysis framework, and using more advanced modeling approaches are suggested as future research tasks.

Development of kinks in car-following models

NASA Astrophysics Data System (ADS)

Kurtze, Douglas A.

2017-03-01

Many car-following models of traffic flow admit the possibility of absolute stability, a situation in which uniform traffic flow at any spacing is linearly stable. Near the threshold of absolute stability, these models can often be reduced to a modified Korteweg-deVries (mKdV) equation plus small corrections. The hyperbolic-tangent "kink" solutions of the mKdV equation are usually of particular interest, as they represent transition zones between regions of different traffic spacings. Solvability analysis is believed to show that only a single member of the one-parameter family of kink solutions is preserved by the correction terms, and this is interpreted as a kind of selection. We show, however, that the usual solvability calculation rests on an unstated, unjustified assumption, and that without this assumption it merely gives a first-order correction to the relation between the traffic spacings far behind and far ahead of the kink, rather than any kind of "selection" criterion for the family of kink solutions. On the other hand, we display a two-parameter family of traveling wave solutions of the mKdV equation, which describe regions of one traffic spacing embedded in traffic of a different spacing; this family includes the kink solutions as a limiting case. We carry out a multiple-time-scales calculation and find conditions under which the inclusions decay, conditions that lead to a selected inclusion, and conditions for which the inclusion evolves into a pair of kinks.

Proposed positive protection guidance for Kansas : synthesis of work zone positive protection devices and state of practice.

DOT National Transportation Integrated Search

2013-02-01

The United States experiences over 700 fatalities and over 37,000 injuries each year in temporary : construction and maintenance work zones. The Federal Highway Administration (FHWA) has implemented : Temporary Traffic Control Devices 23 CFR 630 Subp...

Applicability of Zipper Merge Versus Early Merge in Kentucky Work Zones

DOT National Transportation Integrated Search

2017-12-24

In an effort to improve work zone safety and streamline traffic flows, a number of state transportation agencies (STAs) have experimented with the zipper merge. The zipper merge differs from a conventional, or early, merge in that vehicles do not mer...

An intelligent decision support system for work zone traffic management and planning : executive summary report.

DOT National Transportation Integrated Search

2004-01-01

Problem: Periodic resurfacing, rehabilitation, restoration, and reconstruction work is needed on the aging highway system in the state of Ohio to maintain a desired level of service for the traveling public. However, temporary work zones on highways ...

Minimizing user delay and crash potential through highway work zone planning.

DOT National Transportation Integrated Search

2014-05-01

Lane closures due to highway work zones introduce many challenges to ensuring smooth traffic operations and a : safe environment for drivers and workers. In addition, merging has been found to be one of the most stressful : aspects of driving and a m...

Customer satisfaction with the FHWA peer-to-peer program : a qualitative assessment

DOT National Transportation Integrated Search

1989-07-01

This report is a synthesis of research findings and current practices in controlling and protecting pedestrian traffic in work zones. The information presented here is based on a review of research reports and work zone manuals from a selection of st...

[HYGIENIC ASSESSMENT OF NOISE FACTOR OF THE LARGE CITY].

PubMed

Chubirko, M L; Stepkin, Yu I; Seredenko, O V

2015-01-01

The article is devoted to the problem of the negative impact of traffic noise on the health and living conditions of the population in conditions of the large city. Every day on the streets there are appeared more and more different modes of transport, and to date almost all transportation network has reached his traffic performance. The increase in traffic noise certainly has an impact on the human body. The most common and intense noise is caused by the traffic of urban automobile and electric transport. This is explained by the existence of the heavy traffic (2-3 thousand crews/h) on almost all main roads in historically emerged parts of the city. In addition, sources of external noise in the city can be a railway running in residential zone, access roads, industrial enterprises, located in close proximity to residential areas and on the borders of residential zones, planes of military and civil aviation. For the evaluation of the different noises sound levels were measured with the use of sound level meters. The most common parameter for the assessment ofthe noise generatedfrom motor vehicles on residential areas and usedfor the noise characteristics of the traffic flows, is the equivalent sound level/A EQ dB. This parameter is used in the majority of normative-technical documentation as hygienic noise standard. With the aim of the assessment of noise exposure there were selected 122 control points at intersections of roads of different traffic performance where there were made instrumental measurements the equivalent sound level, followed by its comparison with permissible levels.

GIS-based assessment of cancer risk due to benzene in Tehran ambient air.

PubMed

Atabi, Farideh; Mirzahosseini, Seyed Alireza Hajiseyed

2013-10-01

The present study aimed to assess the risk of cancer due to benzene in the ambient air of gas stations and traffic zones in the north of Tehran. The cancer risk was estimated using the population distribution data for benzene levels and the unit risk for benzene proposed by the United States Environmental Protection Agency (US EPA). Sixteen sampling locations were monitored, once every week, during 5 April 2010 to 25 March 2011. The results showed that the mean annual benzene concentration was 14.51±3.17 parts per billion (ppb) for traffic zones and 29.01±1.32 ppb for outside gas stations. The risk calculated was 1026×10(-6) for gas station 27 and 955×10(-6) for gas station 139. According to our results, the annual benzene level in Tehran ambient air is 2 to 20 times higher than the respective value specified in International Standard (1.56 ppb). Moreover, the results showed a notable increase of cancer risks, ranging from 10% to 56%, for the vicinity population close to the gas stations in comparison to the vicinity population in the traffic zones.

Evaluation of Sources and Patterns of Elemental Composition of PM2.5 at Three Low-Income Neighborhood Schools and Residences in Quito, Ecuador

PubMed Central

Raysoni, Amit U.; Armijos, Rodrigo X.; Weigel, M. Margaret; Echanique, Patricia; Racines, Marcia; Pingitore, Nicholas E.; Li, Wen-Whai

2017-01-01

Elemental characterization of fine particulate matter was undertaken at schools and residences in three low income neighborhoods in Quito, Ecuador. The three zones were located in the northern (Cotocollao), south central (El Camal), and south east (Los Chillos) neighborhoods and were classified as zones 1–3, respectively. Forty elements were quantified via ICP-MS analysis. Amongst the geogenic elements, the concentration of Si was the most abundant followed by S, Al, and Ca. Elements with predominantly anthropogenic sources such as Zn, V, and Ni were higher in zone 3 school followed by zone 2 and zone 1 schools. Enrichment factors were calculated to study the role of crustal sources in the elemental concentrations. Geogenic elements, except K, all had values <10 and anthropogenic elements such as Ni, V, Zn, Pb, As, Cr had >10. Principal Component Analysis suggested that Ni and V concentrations were strongly attributable to pet coke and heavy oil combustion. Strong associations between As and Pb could be attributed to traffic and other industrial emissions. Resuspended dust, soil erosion, vehicular emissions (tailpipe, brake and tire wear, and engine abrasion), pet coke, heavy oil combustion, and heavy industrial operations were major contributors to air pollution. PMID:28644400

Evaluation of Sources and Patterns of Elemental Composition of PM2.5 at Three Low-Income Neighborhood Schools and Residences in Quito, Ecuador.

PubMed

Raysoni, Amit U; Armijos, Rodrigo X; Weigel, M Margaret; Echanique, Patricia; Racines, Marcia; Pingitore, Nicholas E; Li, Wen-Whai

2017-06-23

Elemental characterization of fine particulate matter was undertaken at schools and residences in three low income neighborhoods in Quito, Ecuador. The three zones were located in the northern (Cotocollao), south central (El Camal), and south east (Los Chillos) neighborhoods and were classified as zones 1-3, respectively. Forty elements were quantified via ICP-MS analysis. Amongst the geogenic elements, the concentration of Si was the most abundant followed by S, Al, and Ca. Elements with predominantly anthropogenic sources such as Zn, V, and Ni were higher in zone 3 school followed by zone 2 and zone 1 schools. Enrichment factors were calculated to study the role of crustal sources in the elemental concentrations. Geogenic elements, except K, all had values <10 and anthropogenic elements such as Ni, V, Zn, Pb, As, Cr had >10. Principal Component Analysis suggested that Ni and V concentrations were strongly attributable to pet coke and heavy oil combustion. Strong associations between As and Pb could be attributed to traffic and other industrial emissions. Resuspended dust, soil erosion, vehicular emissions (tailpipe, brake and tire wear, and engine abrasion), pet coke, heavy oil combustion, and heavy industrial operations were major contributors to air pollution.

Modeling Vehicle Collision Angle in Traffic Crashes Based on Three-Dimensional Laser Scanning Data

PubMed Central

Lyu, Nengchao; Huang, Gang; Wu, Chaozhong; Duan, Zhicheng; Li, Pingfan

2017-01-01

In road traffic accidents, the analysis of a vehicle’s collision angle plays a key role in identifying a traffic accident’s form and cause. However, because accurate estimation of vehicle collision angle involves many factors, it is difficult to accurately determine it in cases in which less physical evidence is available and there is a lack of monitoring. This paper establishes the mathematical relation model between collision angle, deformation, and normal vector in the collision region according to the equations of particle deformation and force in Hooke’s law of classical mechanics. At the same time, the surface reconstruction method suitable for a normal vector solution is studied. Finally, the estimation model of vehicle collision angle is presented. In order to verify the correctness of the model, verification of multi-angle collision experiments and sensitivity analysis of laser scanning precision for the angle have been carried out using three-dimensional (3D) data obtained by a 3D laser scanner in the collision deformation zone. Under the conditions with which the model has been defined, validation results show that the collision angle is a result of the weighted synthesis of the normal vector of the collision point and the weight value is the deformation of the collision point corresponding to normal vectors. These conclusions prove the applicability of the model. The collision angle model proposed in this paper can be used as the theoretical basis for traffic accident identification and cause analysis. It can also be used as a theoretical reference for the study of the impact deformation of elastic materials. PMID:28264517

Modeling Vehicle Collision Angle in Traffic Crashes Based on Three-Dimensional Laser Scanning Data.

PubMed

Lyu, Nengchao; Huang, Gang; Wu, Chaozhong; Duan, Zhicheng; Li, Pingfan

2017-02-28

In road traffic accidents, the analysis of a vehicle's collision angle plays a key role in identifying a traffic accident's form and cause. However, because accurate estimation of vehicle collision angle involves many factors, it is difficult to accurately determine it in cases in which less physical evidence is available and there is a lack of monitoring. This paper establishes the mathematical relation model between collision angle, deformation, and normal vector in the collision region according to the equations of particle deformation and force in Hooke's law of classical mechanics. At the same time, the surface reconstruction method suitable for a normal vector solution is studied. Finally, the estimation model of vehicle collision angle is presented. In order to verify the correctness of the model, verification of multi-angle collision experiments and sensitivity analysis of laser scanning precision for the angle have been carried out using three-dimensional (3D) data obtained by a 3D laser scanner in the collision deformation zone. Under the conditions with which the model has been defined, validation results show that the collision angle is a result of the weighted synthesis of the normal vector of the collision point and the weight value is the deformation of the collision point corresponding to normal vectors. These conclusions prove the applicability of the model. The collision angle model proposed in this paper can be used as the theoretical basis for traffic accident identification and cause analysis. It can also be used as a theoretical reference for the study of the impact deformation of elastic materials.

Proposed positive protection guidance for Kansas : synthesis of work zone positive protection devices and state practice : [technical summary].

DOT National Transportation Integrated Search

2013-02-01

The United States experiences over 700 fatalities and over 37,000 injuries each year in : temporary construction and maintenance work zones. The Federal Highway Administration : (FHWA) has implemented Temporary Traffic Control Devices 23 CFR 630 Subp...

22 CFR 123.6 - Foreign trade zones and U.S. Customs and Border Protection bonded warehouses.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Foreign trade zones and U.S. Customs and Border Protection bonded warehouses. 123.6 Section 123.6 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS LICENSES FOR THE EXPORT OF DEFENSE ARTICLES § 123.6 Foreign trade zones and U.S. Customs and Border Protection bonded...

Intelligent Transportation Systems in Work Zones - A Case Study: Work Zone Travel Time System. Reducing Congestion with the Use of a Traffic Management Contract Incentive during the Reconstruction of Arizona State Route 68

DOT National Transportation Integrated Search

2004-10-01

This case study is one in a series of documents that examines the use of Intelligent Transportation Systems (ITS) in work zones. This case study presents information gathered through interviews with key personnel on the Arizona State Route (SR) 68 pr...

Spatial and temporal disaggregation of the on-road vehicle emission inventory in a medium-sized Andean city. Comparison of GIS-based top-down methodologies

NASA Astrophysics Data System (ADS)

Gómez, C. D.; González, C. M.; Osses, M.; Aristizábal, B. H.

2018-04-01

Emission data is an essential tool for understanding environmental problems associated with sources and dynamics of air pollutants in urban environments, especially those emitted from vehicular sources. There is a lack of knowledge about the estimation of air pollutant emissions and particularly its spatial and temporal distribution in South America, mainly in medium-sized cities with population less than one million inhabitants. This work performed the spatial and temporal disaggregation of the on-road vehicle emission inventory (EI) in the medium-sized Andean city of Manizales, Colombia, with a spatial resolution of 1 km × 1 km and a temporal resolution of 1 h. A reported top-down methodology, based on the analysis of traffic flow levels and road network distribution, was applied. Results obtained allowed the identification of several hotspots of emission at the downtown zone and the residential and commercial area of Manizales. Downtown exhibited the highest percentage contribution of emissions normalized by its total area, with values equal to 6% and 5% of total CO and PM10 emissions per km2 respectively. These indexes were higher than those obtained in residential-commercial area with values of 2%/km2 for both pollutants. Temporal distribution showed strong relationship with driving patterns at rush hours, as well as an important influence of passenger cars and motorcycles in emissions of CO both at downtown and residential-commercial areas, and the impact of public transport in PM10 emissions in the residential-commercial zone. Considering that detailed information about traffic counts and road network distribution is not always available in medium-sized cities, this work compares other simplified top-down methods for spatially assessing the on-road vehicle EI. Results suggested that simplified methods could underestimate the spatial allocation of downtown emissions, a zone dominated by high traffic of vehicles. The comparison between simplified methods based on total traffic counts and road density distribution suggested that the use of total traffic counts in a simplified form could enhance higher uncertainties in the spatial disaggregation of emissions. Results obtained could add new information that help to improve the air pollution management system in the city and contribute to local public policy decisions. Additionally, this work provides appropriate resolution emission fluxes for ongoing research in atmospheric modeling in the city, with the aim to improve the understanding of transport, transformation and impacts of pollutant emissions in urban air quality.

Opportunities for Environmental Noise Mapping in Saudi Arabia: A Case of Traffic Noise Annoyance in an Urban Area in Jeddah City.

PubMed

Zytoon, Mohamed A

2016-05-13

As the traffic and other environmental noise generating activities are growing in The Kingdom of Saudi Arabia (KSA), adverse health and other impacts are expected to develop. The management of such problem involves many actions, of which noise mapping has been proven to be a helpful approach. The objective of the current study was to test the adequacy of the available data in KSA municipalities for generating urban noise maps and to verify the applicability of available environmental noise mapping and noise annoyance models for KSA. Therefore, noise maps were produced for Al-Fayha District in Jeddah City, KSA using commercially available noise mapping software and applying the French national computation method "NMPB" for traffic noise. Most of the data required for traffic noise prediction and annoyance analysis were available, either in the Municipality GIS department or in other governmental authorities. The predicted noise levels during the three time periods, i.e., daytime, evening, and nighttime, were found higher than the maximum recommended levels established in KSA environmental noise standards. Annoyance analysis revealed that high percentages of the District inhabitants were highly annoyed, depending on the type of planning zone and period of interest. These results reflect the urgent need to consider environmental noise reduction in KSA national plans. The accuracy of the predicted noise levels and the availability of most of the necessary data should encourage further studies on the use of noise mapping as part of noise reduction plans.

Effects of road construction intensity and operations on rural freeway work zone capacity.

DOT National Transportation Integrated Search

2014-11-01

Capacity is affected by construction type and its intensity on adjacent open traffic lanes. The effect on capacity is a function of : vehicles moving in and out of the closed lanes of the work zone, and the presence of heavy construction vehicles. Co...

Improving the effectiveness of nighttime temporary traffic control warning devices, volume 1 : evaluation of lights on nighttime work zone channelization devices.

DOT National Transportation Integrated Search

2013-10-01

Currently, the Illinois Department of Transportation (IDOT) is one of the few state transportation agencies that : require warning lights on nighttime work zone channelization devices, such as drums and barricades. The intent : of the steady-burn, am...

Public opinion and understanding of advance warning arrow displays used in short-term, mobile, and moving work zones.

DOT National Transportation Integrated Search

2008-03-01

"In long-term work zones on multilane highways and/or freeways, the Federal Highway Administration has interpreted the : Manual on Uniform Traffic Control Devices to mean that only one advance warning arrow displays can be used to denote : the closur...

Reducing work zone crashes by using vehicle's flashers as a warning sign : final report

DOT National Transportation Integrated Search

2009-01-01

Rural two-lane highways constitute a large percentage of the highway system in Kansas. Preserving, expending, : and enhancing these highways require the set-up of a large number of one-lane, two-way work zones where traffic : safety has been a severe...

Speeding in highway work zone: An Evaluation of methods of speed control.

PubMed

Ravani, Bahram; Wang, Chao

2018-04-01

Highway workers frequently work in close proximity of live traffic in highway work zones, traffic accidents therefore have devastating effects on worker safety. In order to reduce the potential for such accidents, methods involving use of advisory signs and police presence have been used to mitigate accident risks and improve safety for highway workers. This research evaluates the magnitude of the speeding problem in highway work zones and the effects of four levels of police presence on improving work zone safety. Speed data were collected in six different work zone locations in northern and southern California and used to determine the magnitude and nature of speeding problem in highway work zones. In addition data were collected over 11 test-days in four work zones with four levels of police presence: radar speed display with police decal and lighting, passive use of a police vehicle with radar speed display, passive use of a police vehicle without radar speed display, and active police speed enforcement near work zones. This paper analyzes this data using statistical methods to evaluate the effectiveness of these different methods of speed control on the safety of the work zone. Four Measures of Effectiveness (MOE) were used in this evaluation consisting of average speed reduction, speed variance, 85th percentile speed, and proportion of high speed vehicles. The results indicate that all levels of police presence provided statistically significant improvements in one or more of the MOEs. Copyright © 2018 Elsevier Ltd. All rights reserved.

The relationship between traffic noise and insomnia among adult Japanese women

NASA Astrophysics Data System (ADS)

Sasazawa, Y.; Kawada, T.; Kiryu, Y.; Suzuki, S.

2004-10-01

To clarify the relationship between traffic noise and insomnia, the authors conducted a survey and measured the actual sound level of noise in an urban area. Questionnaires were distributed to adult women who lived within 150 m from two major roads and were completed by 648 of the 1286 subjects (50.4%). The area was divided into three zones according to distance from the road (more than 50, 20-50 and 0-19.9 m). Fifty-seven subjects (8.8%) were classified as having insomnia. Average values of sound level at distances of 20, 50, and 100 m from the major road were Leq 64.7, 57.1, and 51.8 dBA, respectively. Overall, there were no significant differences among the three zones in the prevalence of insomnia and no association between distance from the road and insomnia. However, the result from a sub-data set of the subjects who lived in the areas that showed decreasing noise level as the distance from the main road increased showed that distance from the road was associated with insomnia. This study suggests that researchers should consider the actual traffic situation and its sound level in epidemiological studies about the effects of traffic noise on insomnia.

Analysis of Traffic Crashes Involving Pedestrians Using Big Data: Investigation of Contributing Factors and Identification of Hotspots.

PubMed

Xie, Kun; Ozbay, Kaan; Kurkcu, Abdullah; Yang, Hong

2017-08-01

This study aims to explore the potential of using big data in advancing the pedestrian risk analysis including the investigation of contributing factors and the hotspot identification. Massive amounts of data of Manhattan from a variety of sources were collected, integrated, and processed, including taxi trips, subway turnstile counts, traffic volumes, road network, land use, sociodemographic, and social media data. The whole study area was uniformly split into grid cells as the basic geographical units of analysis. The cell-structured framework makes it easy to incorporate rich and diversified data into risk analysis. The cost of each crash, weighted by injury severity, was assigned to the cells based on the relative distance to the crash site using a kernel density function. A tobit model was developed to relate grid-cell-specific contributing factors to crash costs that are left-censored at zero. The potential for safety improvement (PSI) that could be obtained by using the actual crash cost minus the cost of "similar" sites estimated by the tobit model was used as a measure to identify and rank pedestrian crash hotspots. The proposed hotspot identification method takes into account two important factors that are generally ignored, i.e., injury severity and effects of exposure indicators. Big data, on the one hand, enable more precise estimation of the effects of risk factors by providing richer data for modeling, and on the other hand, enable large-scale hotspot identification with higher resolution than conventional methods based on census tracts or traffic analysis zones. © 2017 Society for Risk Analysis.

Factors associated with NO2 and NOX concentration gradients near a highway.

PubMed

Richmond-Bryant, J; Snyder, M G; Owen, R C; Kimbrough, S

2017-11-21

The objective of this research is to learn how the near-road gradient, in which NO 2 and NO X (NO + NO 2 ) concentrations are elevated, varies with changes in meteorological and traffic variables. Measurements of NO 2 and NO X were obtained east of I-15 in Las Vegas and fit to functions whose slopes (dC NO 2 /dx and dC NO X /dx, respectively) characterize the size of the near-road zone where NO 2 and NO X concentrations from mobile sources on the highway are elevated. These metrics were used to learn about the near-road gradient by modeling dC NO 2 /dx and dC NO X /dx as functions of meteorological variables (e.g., wind direction, wind speed), traffic (vehicle count), NO X concentration upwind of the road, and O 3 concentration at two fixed-site ambient monitors. Generalized additive models (GAM) were used to model dC NO 2 /dx and dC NO X /dx versus the independent variables because they allowed for nonlinearity of the variables being compared. When data from all wind directions were included in the analysis, variability in O 3 concentration comprised the largest proportion of variability in dC NO 2 /dx, followed by variability in wind direction. In a second analysis constrained to winds from the west, variability in O 3 concentration remained the largest contributor to variability in dC NO 2 /dx, but the relative contribution of variability in wind speed to variability in dC NO 2 /dx increased relative to its contribution for the all-wind analysis. When data from all wind directions were analyzed, variability in wind direction was by far the largest contributor to variability in dC NO X /dx, with smaller contributions from hour of day and upwind NO X concentration. When only winds from the west were analyzed, variability in upwind NO X concentration, wind speed, hour of day, and traffic count all were associated with variability in dC NO X /dx. Increases in O 3 concentration were associated with increased magnitude near-road dC NO 2 /dx, possibly shrinking the zone of elevated concentrations occurring near roads. Wind direction parallel to the highway was also related to an increased magnitude of both dC NO 2 /dx and dC NO X /dx, again likely shrinking the zone of elevated concentrations occurring near roads. Wind direction perpendicular to the road decreased the magnitude of dC NO 2 /dx and dC NO X /dx and likely contributed to growth of the zone of elevated concentrations occurring near roads. Thus, variability in near-road concentrations is influenced by local meteorology and ambient O 3 concentration.

The investigation of the lateral interaction effect's on traffic flow behavior under open boundaries

NASA Astrophysics Data System (ADS)

Bouadi, M.; Jetto, K.; Benyoussef, A.; El Kenz, A.

2017-11-01

In this paper, an open boundaries traffic flow system is studied by taking into account the lateral interaction with spatial defects. For a random defects distribution, if the vehicles velocities are weakly correlated, the traffic phases can be predicted by considering the corresponding inflow and outflow functions. Conversely, if the vehicles velocities are strongly correlated, a phase segregation appears inside the system's bulk which induces the maximum current appearance. Such velocity correlation depends mainly on the defects densities and the probabilities of lateral deceleration. However, for a compact defects distribution, the traffic phases are predictable by using the inflow in the system beginning, the inflow entering the defects zone and the outflow function.

Urban planning and traffic safety at night

NASA Astrophysics Data System (ADS)

Ispas, N.; Trusca, D.

2016-08-01

Urban planning including traffic signs serve vital functions, providing road users with regulatory, warning and guidance information about the roadway and surrounding environment. There are a large number of signs and even more guidelines on how these signs should be designed, installed, and maintained in concordance with on road surface traffic signs. More requirements for signs are made for night urban traffic, including appearance (size, shape, colour), placement (height, lateral, and longitudinal), maintenance (visibility, position, damage) and signs light and retroreflective. In the night, traffic signs visibility can interact by on pedestrian visibility and diminish urban traffic safety. The main aim of this paper are the scientific determination of an urban specific zone visibility for evaluate at night real conditions in case of a traffic accident in the Braşov city area. The night visibility study was made using PC-Rect version 4.2. Other goal of the paper was to modify some urban planning solution in order to increase the urban safety in Brașov.

Effects of heterogeneous traffic with speed limit zone on the car accidents

NASA Astrophysics Data System (ADS)

Marzoug, R.; Lakouari, N.; Bentaleb, K.; Ez-Zahraouy, H.; Benyoussef, A.

2016-06-01

Using the extended Nagel-Schreckenberg (NS) model, we numerically study the impact of the heterogeneity of traffic with speed limit zone (SLZ) on the probability of occurrence of car accidents (Pac). SLZ in the heterogeneous traffic has an important effect, typically in the mixture velocities case. In the deterministic case, SLZ leads to the appearance of car accidents even in the low densities, in this region Pac increases with increasing of fraction of fast vehicles (Ff). In the nondeterministic case, SLZ decreases the effect of braking probability Pb in the low densities. Furthermore, the impact of multi-SLZ on the probability Pac is also studied. In contrast with the homogeneous case [X. Li, H. Kuang, Y. Fan and G. Zhang, Int. J. Mod. Phys. C 25 (2014) 1450036], it is found that in the low densities the probability Pac without SLZ (n = 0) is low than Pac with multi-SLZ (n > 0). However, the existence of multi-SLZ in the road decreases the risk of collision in the congestion phase.

Evaluation of the Impact of Low Emission Zone and Heavy Traffic Ban in Munich (Germany) on the Reduction of PM10 in Ambient Air

PubMed Central

Fensterer, Veronika; Küchenhoff, Helmut; Maier, Verena; Wichmann, Heinz-Erich; Breitner, Susanne; Peters, Annette; Gu, Jianwei; Cyrys, Josef

2014-01-01

Concentrations of ambient fine particles (PM10: particles with an aerodynamic diameter ≤ 10 µm) are still exceeding current air quality standards in many European cities. In Munich (Germany), low emission zone and transit bans for heavy-duty vehicles were introduced in 2008 aiming at reduction of traffic emissions contribution to PM10. The effects of those measures on PM10 mass concentrations in Munich were investigated with a semiparametric regression model for modeling PM10 levels adjusted for time, background pollution, public holidays and wind direction. The reduction of PM10 concentration after the introduction of the measures was larger at a traffic monitoring site (13.0 %, 19.6 % in summer, and 6.8 % in winter) and smaller in urban background (4.5 %, 5.7 % in summer, and 3.2 % in winter). The effect was most pronounced on Fridays and on the weekends in summer. PMID:24828081

49 CFR Appendix C to Part 222 - Guide to Establishing Quiet Zones

Code of Federal Regulations, 2011 CFR

2011-10-01

... Horns will not be subject to annual reviews. (5) The use of FRA's web-based Quiet Zone Calculator is... appendix A (e.g., shorter than required traffic channelization devices), non-engineering ASMs (e.g., programmed law enforcement), and engineering ASMs (i.e., engineering improvements other than modified SSMs...

77 FR 45490 - Safety Zone, Barrel Recovery, Lake Superior; Duluth, MN

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-01

... suspected to contain munitions waste materials which were dumped in the 1960's in a portion of Lake Superior... recreational vessels and marine traffic from any unknown hazards as well as provide a safe work zone for... Waterways Management, U.S. Coast Guard Marine Safety Unit Duluth; telephone number (218) 720- 5286...

77 FR 37319 - Safety Zone for Fifth Coast Guard District Fireworks Display Pasquotank River; Elizabeth City, NC

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-21

...-AA00 Safety Zone for Fifth Coast Guard District Fireworks Display Pasquotank River; Elizabeth City, NC... the Pasquotank River, Elizabeth City, North Carolina. The fireworks display ordinarily originated from... vessel traffic in a portion of the Pasquotank River, Elizabeth City, North Carolina, during the event...

23 CFR 630.1108 - Work zone safety management measures and strategies.

Code of Federal Regulations, 2013 CFR

2013-04-01

... workers and road users, such as: (1) Work zones that provide workers no means of escape from motorized... exposure to motorized traffic and exposure of road users to work activities, while also providing adequate... individual projects, such as: (1) Full road closures; (2) Ramp closures; (3) Median crossovers; (4) Full or...

23 CFR 630.1108 - Work zone safety management measures and strategies.

Code of Federal Regulations, 2012 CFR

2012-04-01

... workers and road users, such as: (1) Work zones that provide workers no means of escape from motorized... exposure to motorized traffic and exposure of road users to work activities, while also providing adequate... individual projects, such as: (1) Full road closures; (2) Ramp closures; (3) Median crossovers; (4) Full or...

23 CFR 630.1108 - Work zone safety management measures and strategies.

Code of Federal Regulations, 2011 CFR

2011-04-01

... workers and road users, such as: (1) Work zones that provide workers no means of escape from motorized... exposure to motorized traffic and exposure of road users to work activities, while also providing adequate... individual projects, such as: (1) Full road closures; (2) Ramp closures; (3) Median crossovers; (4) Full or...

23 CFR 630.1108 - Work zone safety management measures and strategies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... workers and road users, such as: (1) Work zones that provide workers no means of escape from motorized... exposure to motorized traffic and exposure of road users to work activities, while also providing adequate... individual projects, such as: (1) Full road closures; (2) Ramp closures; (3) Median crossovers; (4) Full or...

78 FR 39599 - Safety Zone; Fort Monroe Fireworks Display, Chesapeake Bay, Hampton, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

.... ACTION: Temporary Final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on the... intended to restrict vessel traffic movement in the specified area in order to protect the life and... Federal holidays. FOR FURTHER INFORMATION CONTACT: If you have questions on this temporary rule, call or...

78 FR 53668 - Regulated Navigation Area; Maine Kennebec Bridge Construction Zone, Kennebec River, Richmond, ME

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

...-AA11 Regulated Navigation Area; Maine Kennebec Bridge Construction Zone, Kennebec River, Richmond, ME... surrounding the Maine Kennebec Bridge between Richmond, ME, and Dresden, ME. This RNA allows the Coast Guard to enforce speed and wake restrictions and prohibit all vessel traffic through the RNA during bridge...

77 FR 65621 - Security Zone; Cruise Ships, Santa Barbara Harbor, Santa Barbara, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-30

... able to locate the cruise ships visually, due to the small geographic size and depth restrictions of... entities because vessel traffic can pass safely around the zones. If you think that your business... significant economic impact on it, please submit a comment (see ADDRESSES) explaining why you think it...

77 FR 31183 - Safety Zone, Temporary Change for Recurring Fireworks Display Within the Fifth Coast Guard...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-25

...-AA00 Safety Zone, Temporary Change for Recurring Fireworks Display Within the Fifth Coast Guard District, Pamlico River and Tar River; Washington, NC AGENCY: Coast Guard, DHS. ACTION: Temporary final... is intended to restrict vessel traffic in a portion of the Pamlico River and Tar River near...

Integrated risk management for improving internal traffic control, work-zone safety, and mobility during major construction : tech transfer summary.

DOT National Transportation Integrated Search

2012-10-01

Construction work zones are among the most dangerous places to work in any industry in the world. This is because many factors in construction, such as constant change in working environments and driver errors, contribute to a workplace with a higher...

Evaluation of the Scottsdale Loop 101 automated speed enforcement demonstration program.

PubMed

Shin, Kangwon; Washington, Simon P; van Schalkwyk, Ida

2009-05-01

Speeding is recognized as a major contributing factor in traffic crashes. In order to reduce speed-related crashes, the city of Scottsdale, Arizona implemented the first fixed-camera photo speed enforcement program (SEP) on a limited access freeway in the US. The 9-month demonstration program spanning from January 2006 to October 2006 was implemented on a 6.5 mile urban freeway segment of Arizona State Route 101 running through Scottsdale. This paper presents the results of a comprehensive analysis of the impact of the SEP on speeding behavior, crashes, and the economic impact of crashes. The impact on speeding behavior was estimated using generalized least square estimation, in which the observed speeds and the speeding frequencies during the program period were compared to those during other periods. The impact of the SEP on crashes was estimated using 3 evaluation methods: a before-and-after (BA) analysis using a comparison group, a BA analysis with traffic flow correction, and an empirical Bayes BA analysis with time-variant safety. The analysis results reveal that speeding detection frequencies (speeds> or =76 mph) increased by a factor of 10.5 after the SEP was (temporarily) terminated. Average speeds in the enforcement zone were reduced by about 9 mph when the SEP was implemented, after accounting for the influence of traffic flow. All crash types were reduced except rear-end crashes, although the estimated magnitude of impact varies across estimation methods (and their corresponding assumptions). When considering Arizona-specific crash related injury costs, the SEP is estimated to yield about $17 million in annual safety benefits.

Carbon dioxide emission and bio-capacity indexing for transportation activities: A methodological development in determining the sustainability of vehicular transportation systems.

PubMed

Labib, S M; Neema, Meher Nigar; Rahaman, Zahidur; Patwary, Shahadath Hossain; Shakil, Shahadat Hossain

2018-06-09

CO 2 emissions from urban traffic are a major concern in an era of increasing ecological disequilibrium. Adding to the problem net CO 2 emissions in urban settings are worsened due to the decline of bio-productive areas in many cities. This decline exacerbates the lack of capacity to sequestrate CO 2 at the micro and meso-scales resulting in increased temperatures and decreased air quality within city boundaries. Various transportation and environmental strategies have been implemented to address traffic related CO 2 emissions, however current literature identifies difficulties in pinpointing these critical areas of maximal net emissions in urban transport networks. This study attempts to close this gap in the literature by creating a new lay-person friendly index that combines CO 2 emissions from vehicles and the bio-capacity of specific traffic zones to identify these areas at the meso-scale within four ranges of values with the lowest index values representing the highest net CO 2 levels. The study used traffic volume, fuel types, and vehicular travel distance to estimate CO 2 emissions at major links in Dhaka, Bangladesh's capital city's transportation network. Additionally, using remote-sensing tools, adjacent bio-productive areas were identified and their bio-capacity for CO 2 sequestration estimated. The bio-productive areas were correlated with each traffic zone under study resulting in an Emission Bio-Capacity index (EBI) value estimate for each traffic node. Among the ten studied nodes in Dhaka City, nine had very low EBI values, correlating to very high CO 2 emissions and low bio-capacity. As a result, the study considered these areas unsustainable as traffic nodes going forward. Key reasons for unsustainability included increasing use of motorized traffic, absence of optimized signal systems, inadequate public transit options, disincentives for fuel free transport (FFT), and a decline in bio-productive areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

Opportunities for Environmental Noise Mapping in Saudi Arabia: A Case of Traffic Noise Annoyance in an Urban Area in Jeddah City

PubMed Central

Zytoon, Mohamed A.

2016-01-01

As the traffic and other environmental noise generating activities are growing in The Kingdom of Saudi Arabia (KSA), adverse health and other impacts are expected to develop. The management of such problem involves many actions, of which noise mapping has been proven to be a helpful approach. The objective of the current study was to test the adequacy of the available data in KSA municipalities for generating urban noise maps and to verify the applicability of available environmental noise mapping and noise annoyance models for KSA. Therefore, noise maps were produced for Al-Fayha District in Jeddah City, KSA using commercially available noise mapping software and applying the French national computation method “NMPB” for traffic noise. Most of the data required for traffic noise prediction and annoyance analysis were available, either in the Municipality GIS department or in other governmental authorities. The predicted noise levels during the three time periods, i.e., daytime, evening, and nighttime, were found higher than the maximum recommended levels established in KSA environmental noise standards. Annoyance analysis revealed that high percentages of the District inhabitants were highly annoyed, depending on the type of planning zone and period of interest. These results reflect the urgent need to consider environmental noise reduction in KSA national plans. The accuracy of the predicted noise levels and the availability of most of the necessary data should encourage further studies on the use of noise mapping as part of noise reduction plans. PMID:27187438

77 FR 35848 - Safety Zone, Fourth of July Fireworks Event, Pagan River, Smithfield, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-15

.... ACTION: Temporary Final rule. SUMMARY: The Coast Guard is establishing a 420-foot radius safety zone on..., and falling hot embers or other debris, vessel traffic will be temporarily restricted within 420 feet... navigable waters of the Pagan River within the area bounded by a 420-foot radius circle centered on position...

Impact assessment of incident scene work zone alerts for drivers and workers (INC-ZONE) and incident scene pre-arrival staging guidance for emergency responders (RESP-STG).

DOT National Transportation Integrated Search

2015-05-01

Response, Emergency Staging and Communications, Uniform Management, and Evacuation (R.E.S.C.U.M.E.) is a bundle of applications that targets the improvement of traffic safety and mobility during crashes and other emergencies that affect the highway n...

75 FR 23212 - Security Zone; U.S. Coast Guard BSU Seattle, Pier 36, Seattle, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... FR 3316). Public Meeting We do not now plan to hold a public meeting. But you may submit a request... reason: Vessel traffic can pass safely around the security zone. If you think that your business... do not individually or cumulatively have a significant effect on the human environment. A preliminary...

75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

75 FR 26157 - Safety Zone; Reedville July 4th Celebration, Cockrell's Creek, Reedville, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

...-AA00 Safety Zone; Reedville July 4th Celebration, Cockrell's Creek, Reedville, VA AGENCY: Coast Guard... Reedville July 4th Celebration event. This action is intended to restrict vessel traffic movement on... established in the interest of public safety during the Reedville July 4th Celebration event and will be...

Signal treatments to reduce heavy vehicle crash-risk at metropolitan highway intersections.

PubMed

Archer, Jeffery; Young, William

2009-05-01

Heavy vehicle red-light running at intersections is a common safety problem that has severe consequences. This paper investigates alternative signal treatments that address this issue. A micro-simulation analysis approach was adopted as a precursor to a field trial. The simulation model emulated traffic conditions at a known problem intersection and provided a baseline measure to compare the effects of: an extension of amber time; an extension of green for heavy vehicles detected in the dilemma zone at the onset of amber; an extension of the all-red safety-clearance time based on the detection of vehicles considered likely to run the red light at two detector locations during amber; an extension of the all-red safety-clearance time based on the detection of potential red-light runners during amber or red; and a combination of the second and fourth alternatives. Results suggested safety improvements for all treatments. An extension of amber provided the best safety effect but is known to be prone to behavioural adaptation effects and wastes traffic movement time unnecessarily. A green extension for heavy vehicles detected in the dilemma zone and an all-red extension for potential red-light runners were deemed to provide a sustainable safety improvement and operational efficiency.

C4 plant isotopic composition (delta13C) evidence for urban CO2 pollution in the city of Cotonou, Benin (West Africa).

PubMed

Kèlomé, Nelly C; Lévêque, Jean; Andreux, Francis; Milloux, Marie-Jeanne; Oyédé, Lucien-Marc

2006-08-01

The carbon isotopic composition (delta13C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The delta13C values of air and plants depend on the amount of atmospheric fossil fuel CO2, which is chiefly emitted in urban areas. A new indicator of CO2 pollution is tested using the delta13C variation in a C4 grass: Eleusine indica. A range of about 4 per thousand delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest delta13C values, from -12 per thousand to -14 per thousand, were found in low traffic zones; low delta13C values, from -14 per thousand to -16 per thousand, were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant delta13C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The delta13C dataset and the corresponding geographical database were used to map and define zones of high and low 13C-depleted CO2 emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO2 emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation.

Determining Level of Service for Multilane Median Opening Zone

NASA Astrophysics Data System (ADS)

Ali, Paydar; Johnnie, Ben-Edigbe

2017-08-01

The road system is a capital-intensive investment, requiring thorough schematic framework and funding. Roads are built to provide an intrinsic quality of service which satisfies the road users. Roads that provide good services are expected to deliver operational performance that is consistent with their design specifications. Level of service and cumulative percentile speed distribution methods have been used in previous studies to estimate the quality of multilane highway service. Whilst the level of service approach relies on speed/flow curve, the cumulative percentile speed distribution is based solely speed. These estimation methods were used in studies carried out in Johor Malaysia. The aim of the studies is to ascertain the extent of speed reduction caused by midblock U-turn facilities as well as verify which estimation method is more reliable. At selected sites, road segments for both directional flows were divided into free-flow and midblock zones. Traffic volume, speed and vehicle type data for each zone were collected continuously for six weeks. Both estimation methods confirmed that speed reduction would be caused by midblock u-turn facilities. However level of service methods suggested that the quality of service would improve from level F to E or D at midblock zone in spite of speed reduction. Level of service was responding to traffic volume reduction at midblock u-turn facility not travel speed reduction. The studies concluded that since level of service was more responsive to traffic volume reduction than travel speed, it cannot be solely relied upon when assessing the quality of multilane highway service.

Traffic safety program for school children through safe action and safe condition

NASA Astrophysics Data System (ADS)

Yulianto, Budi; Setiono, Mahmudah, Amirotul Musthofiah Hidayah; Santoso, Anjar Budi

2017-06-01

The facts indicate that the rights of pedestrians is on the wane. Many motorists are unwilling to provide a space for pedestrians, even when they want to cross the road at zebra-cross facility. The data of traffic accident in Surakarta City showed that 7.0% of accident victims in 2014 to 2015 were children aged 5-15 or the group of school-aged children. In general, the location of schools is on the edge of the road where a lot of vehicles run at high speed. Hence, it is very dangerous for the school children to cross the road. Pertaining to this issue, the Department of Transportation implements a program named School Safety Zone (ZoSS). ZoSS is a time-dependent speed control zone consisting of road markings, traffic signs, optional traffic signals, and rumble strips. The objective of this study was to evaluate the effectiveness of the ZoSS based on the perception of the users, including the students, teachers, parents, and community. This study was conducted through a series of activities including the distribution of questionnaire to obtain the road users' perceptions. The results showed that most of the respondents understood the meaning, aim, and benefit of ZoSS. However, it also found that traffic sign and method of cross the road (Four-T) was not recognized appropriately by the respondents. ZoSS program was generally ineffective since the pedestrians felt unsafe to cross the road due to the high-speed vehicles.

Characterization of traffic-related air pollutant metrics at four schools in El Paso, Texas, USA: Implications for exposure assessment and siting schools in urban areas

NASA Astrophysics Data System (ADS)

Raysoni, Amit U.; Stock, Thomas H.; Sarnat, Jeremy A.; Montoya Sosa, Teresa; Ebelt Sarnat, Stefanie; Holguin, Fernando; Greenwald, Roby; Johnson, Brent; Li, Wen-Whai

2013-12-01

Children spend substantial amount of time within school microenvironments; therefore, assessing school-based exposures is essential for characterizing and preventing children's health risks to air pollutants. Indeed, the importance of characterizing children's exposures in schools is recognized by the US Environmental Protection Agency's recent initiative to promote outdoor air monitoring networks near schools. As part of a health effects study investigating the impact of traffic-related air pollution on asthmatic children along the US-Mexico border, this research examines children's exposures to, and spatio-temporal heterogeneity in concentrations of, traffic-related air pollutants at four elementary schools in El Paso, Texas. Three schools were located in an area of high traffic density and one school in an area of low traffic density. Paired indoor and outdoor concentrations of 48-h fine and coarse particulate matter (PM2.5 and PM10-2.5), 48-h black carbon (BC), 96-h nitrogen dioxide (NO2), and 96-h volatile organic compounds (VOCs) were measured for 13 weeks at each school. Outdoor concentrations of PM, NO2, BC, and BTEX (benzene, toluene, ethylbenzene, m,p-xylene, o-xylene) compounds were similar among the three schools in the high-traffic zone in contrast to the school in the low-traffic zone. Results from this study and previous studies in this region corroborate the fact that PM pollution in El Paso is dominated by coarse PM (PM10-2.5) and fine fraction (PM2.5) accounts for only 25-30% of the total PM mass in PM10. BTEX species and BC are better surrogates for traffic air pollution in this region. Correlation analyses indicate a range of association between indoor and outdoor pollutant concentrations due to uncontrollable factors like student foot traffic and varying building and ventilation configurations across the four schools. Results suggest the need of micro-scale monitoring for children's exposure assessment, which may not be adequately characterized by the measurements from a centralized monitoring site.

Low level off-road vehicle (ORV) traffic negatively impacts macroinvertebrate assemblages at sandy beaches in south-western Australia

NASA Astrophysics Data System (ADS)

Davies, Rebecca; Speldewinde, Peter C.; Stewart, Barbara A.

2016-04-01

Off-road vehicle use is arguably one of the most environmentally damaging human activities undertaken on sandy beaches worldwide. Existing studies focused on areas of high traffic volumes have demonstrated significantly lower abundance, diversity and species richness of fauna in zones where traffic is concentrated. The impact of lower traffic volumes is unknown. This study aimed to investigate the impacts of relatively low-level vehicle traffic on sandy beach fauna by sampling invertebrate communities at eight beaches located in south-western Australia. We found that even low-level vehicle traffic negatively impacts the physical beach environment, and consequently, the ability of many species to survive in this habitat in the face of this disturbance. Compaction, rutting and displacement of the sand matrix were observed over a large area, resulting in significant decreases in species diversity and density, and measurable shifts in community structure on beaches that experienced off-road vehicle traffic. Communities at impact sites did not display seasonal recovery as traffic was not significantly different between seasons. Given a choice between either reducing traffic volumes, or excluding ORV traffic from beaches, our results suggest that the latter would be more appropriate when the retention of ecological integrity is the objective.

Improving pedestrian facilities in congested urban areas: a case study of Chennai city

NASA Astrophysics Data System (ADS)

Subramanyam, B.; Prasanna Kumar, R.

2017-07-01

Traffic congestion and lack of public pedestrian space are some problems faced by most urban metropolises. Conventionally walking has been a mode of transportation in Indian cities. The percentage of pedestrians may vary from 16 to 57 depending upon the city. Encounters between vehicular traffic and pedestrian traffic are at its rise currently. Rapid industrialization and urbanization in India has resulted in neglecting of pedestrian facilities. Consequently pedestrian are at greater risk for their safety more especially in the commercial zones of large cities. A change in perspective spotlight will create a sense of awareness that the pedestrian traffic is also vital as the vehicular traffic. Soothing the traffic would moderately cut the driving expediency but the pedestrians will get a much safer and peaceful route to their terminuses. Safety and comfort are the two pans of a balance while considering the pedestrian traffic. Considering these aspects, this study deals a study in improving pedestrian facilities by analysing the existing skeleton of the selected locations. The adequacy of facility is checked based on IRC latest guidelines and counteractive measures are postulated.

Vehicle emission implications of drivers' smart advisory system for traffic operations in work zones.

PubMed

Li, Qing; Qiao, Fengxiang; Yu, Lei

2016-05-01

Wireless communication systems have been broadly applied in various complicated traffic operations to improve mobility and safety on roads, which may raise a concern about the implication of the new technology on vehicle emissions. This paper explores how the wireless communication systems improve drivers' driving behaviors and its contributions to the emission reduction, in terms of Operating Mode (OpMode) IDs distribution used in emission estimation. A simulated work zone with completed traffic operation was selected as a test bed. Sixty subjects were recruited for the tests, whose demographic distribution was based on the Census data in Houston, Texas. A scene of a pedestrian's crossing in the work zone was designed for the driving test. Meanwhile, a wireless communication system called Drivers Smart Advisory System (DSAS) was proposed and introduced in the driving simulation, which provided drivers with warning messages in the work zone. Two scenarios were designed for a leading vehicle as well as for a following vehicle driving through the work zone, which included a base test without any wireless communication systems, and a driving test with the trigger of the DSAS. Subjects' driving behaviors in the simulation were recorded to evaluate safety and estimate the vehicle emission using the Environmental Protection Agency (EPA) released emission model MOVES. The correlation between drivers' driving behavior and the distribution of the OpMode ID during each scenario was investigated. Results show that the DSAS was able to induce drivers to accelerate smoothly, keep longer headway distance and stop earlier for a hazardous situation in the work zone, which driving behaviors result in statistically significant reduction in vehicle emissions for almost all studied air pollutants (p-values range from 4.10E-51 to 2.18E-03). The emission reduction was achieved by the switching the distribution of the OpMode IDs from higher emission zones to lower emission zones. Transportation section is a significant source of greenhouse gas emissions. Many studies demonstrate that the wireless communication system dedicated for safety and mobility issues may contribute to the induction in vehicle emissions through changing driving behaviors. An insight into the correlation between the driving behaviors and the distribution of Operating Mode (OpMode) IDs is essential to enhance the emission reduction. The result of this study shows that with a Drivers Smart Advisory System (DSAS) drivers accelerated smoothly and stopped earlier for a hazardous situation, which induce the switch of the OpMode IDs from high emission zones to lower emission zones.

78 FR 46258 - Safety Zone; Upper Mississippi River, Mile 662.8 to 663.9

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

...-AA00 Safety Zone; Upper Mississippi River, Mile 662.8 to 663.9 AGENCY: Coast Guard, DHS. ACTION... Upper Mississippi River, from mile 662.8 to 663.9, extending the entire width of the river. This safety... mile 662.8 to 663.9 on the Upper Mississippi River. Anticipated traffic on the river presents safety...

76 FR 38570 - Safety Zone; Fourth of July Fireworks Event, Pagan River, Smithfield, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-01

.... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a 420-foot radius safety zone on..., vessel traffic will be temporarily restricted within 420 feet of the fireworks launch site. Discussion of... the area bounded by a 420-foot radius circle centered on position 36[deg]59'18'' N/076[deg]37'45'' W...

75 FR 34372 - Safety Zone; Fourth of July Fireworks Event, Pagan River, Smithfield, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-17

.... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a 420-foot radius safety zone on... other debris, vessel traffic will be temporarily restricted within 420 feet of the fireworks launch site... within the area bounded by a 420-foot radius circle centered on position 36[deg]59'18'' N/076[deg]37'45...

75 FR 54026 - Safety Zone; Red Bull Flugtag, Delaware River, Camden, NJ

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-03

... Franklin Bridge. The safety zone will restrict vessel traffic from a portion of the Delaware River [email protected] . If you have questions on viewing the docket, call Renee V. Wright, Program Manager... from vessels and vessels from any debris in the water as a result from the event. Under 5 U.S.C. 553(d...

An empirical model to predict road dust emissions based on pavement and traffic characteristics.

PubMed

Padoan, Elio; Ajmone-Marsan, Franco; Querol, Xavier; Amato, Fulvio

2018-06-01

The relative impact of non-exhaust sources (i.e. road dust, tire wear, road wear and brake wear particles) on urban air quality is increasing. Among them, road dust resuspension has generally the highest impact on PM concentrations but its spatio-temporal variability has been rarely studied and modeled. Some recent studies attempted to observe and describe the time-variability but, as it is driven by traffic and meteorology, uncertainty remains on the seasonality of emissions. The knowledge gap on spatial variability is much wider, as several factors have been pointed out as responsible for road dust build-up: pavement characteristics, traffic intensity and speed, fleet composition, proximity to traffic lights, but also the presence of external sources. However, no parameterization is available as a function of these variables. We investigated mobile road dust smaller than 10 μm (MF10) in two cities with different climatic and traffic conditions (Barcelona and Turin), to explore MF10 seasonal variability and the relationship between MF10 and site characteristics (pavement macrotexture, traffic intensity and proximity to braking zone). Moreover, we provide the first estimates of emission factors in the Po Valley both in summer and winter conditions. Our results showed a good inverse relationship between MF10 and macro-texture, traffic intensity and distance from the nearest braking zone. We also found a clear seasonal effect of road dust emissions, with higher emission in summer, likely due to the lower pavement moisture. These results allowed building a simple empirical mode, predicting maximal dust loadings and, consequently, emission potential, based on the aforementioned data. This model will need to be scaled for meteorological effect, using methods accounting for weather and pavement moisture. This can significantly improve bottom-up emission inventory for spatial allocation of emissions and air quality management, to select those roads with higher emissions for mitigation measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Petroleum hydrocarbon pollution of urban topsoil in Ibadan city, Nigeria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onianwa, P.C.

The distribution of total petroleum hydrocarbon in topsoils from various parts of Ibadan city, Nigeria, was studied. Samples were selected from around the following zones: (a) railway tracks, (b) petrol stations, (c) refuse dumps, (d) residential areas, (e) high traffic density areas, (f) mechanical workshops, and (g) control zones. Contamination of the topsoil with hydrocarbons was significant only around petrol stations and mechanical workshops where the factors of accumulation were 10.1 and 4.72, respectively. The general trend in hydrocarbon levels was petrol station > mechanical workshop > refuse dumps > high traffic areas {ge} rail tracks > control residential areas.more » The results highlight the need to monitor urban environments that are remote from petroleum exploration activities for petroleum hydrocarbon contamination. 19 refs., 3 tabs.« less

Ramp - Metering Algorithms Evaluated within Simplified Conditions

NASA Astrophysics Data System (ADS)

Janota, Aleš; Holečko, Peter; Gregor, Michal; Hruboš, Marián

2017-12-01

Freeway networks reach their limits, since it is usually impossible to increase traffic volumes by indefinitely extending transport infrastructure through adding new traffic lanes. One of the possible solutions is to use advanced intelligent transport systems, particularly ramp metering systems. The paper shows how two particular algorithms of local and traffic-responsive control (Zone, ALINEA) can be adapted to simplified conditions corresponding to Slovak freeways. Both control strategies are modelled and simulated using PTV Vissim software, including the module VisVAP. Presented results demonstrate the properties of both control strategies, which are compared mutually as well as with the initial situation in which no control strategy is applied

Characteristics of tree bark as an indicator in high-immission areas : II. Contents of heavy metals.

PubMed

Lötschert, W; Köhm, H -J

1978-01-01

1. Studies on indicator characteristics of bark of deciduous trees have been continued by measuring accumulation of Pb, Cd, Ni and Mn in the bark of Fraxinus excelsior at 34 sampling sites over an area of 150 km 2 in the immission area of Frankfurt am Main. 2. Iso-lines of equal Pb-contamination have been found. They include zones of graduated immissions. The pattern of these zones shows an eccentrical orientation and is the result of the distribution of the main traffic roads. A significant correlation of Pb in the bark and traffic congestion has been found. 3. The zones of Cd-contamination stretch from SW to NE. The orientation of these zones is determined by the distribution of the big emittenrs and the centers of heating power in the area and the predominating direction of wind. 4. A correlation between the accumulation of Pb and Cd has been detected. It is less significant than that between pH-value and sulfur content in the bark of trees in former investigations. 5. The distribution of Pb and Mn is antagonistic in the bark of Fraxinus excelsior and parallel in the needles of Taxus baccata. The content of Mn in the bark of Fraxinus is low. It must be accepted that this is partly an effect of elution by sulfur acid-aerosol formation. 6. The strongest accumulation of heavy metal immissions is found in mosses on the ground, mainly in Bryum argenteum. Nevertheless the bark of Fraxinus excelsior has shown consequently its accumulation characteristics as a good immission indicator for heavy metal contaminations by traffic and big emittents.

75 FR 34927 - Safety Zone; Parade of Ships, Seattle SeaFair Fleet Week, Pier 66, Elliott Bay, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

...-AA00 Safety Zone; Parade of Ships, Seattle SeaFair Fleet Week, Pier 66, Elliott Bay, WA AGENCY: Coast... Seattle SeaFair Fleet Week. This action is intended to restrict vessel traffic movement and entry into... of Ships for the annual Seattle SeaFair Fleet Week. For the purposes of this rule the Parade of Ships...

12 CFR 303.42 - Filing procedures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... contracts; (4) A statement on the impact of the proposal on the human environment, including, information on compliance with local zoning laws and regulations and the effect on traffic patterns for purposes of...

12 CFR 303.42 - Filing procedures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... contracts; (4) A statement on the impact of the proposal on the human environment, including, information on compliance with local zoning laws and regulations and the effect on traffic patterns for purposes of...

12 CFR 303.42 - Filing procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... contracts; (4) A statement on the impact of the proposal on the human environment, including, information on compliance with local zoning laws and regulations and the effect on traffic patterns for purposes of...

Reconsidering brownfield redevelopment strategy in China's old industrial zone: a health risk assessment of heavy metal contamination.

PubMed

Ren, Wanxia; Geng, Yong; Ma, Zhixiao; Sun, Lina; Xue, Bing; Fujita, Tsuyoshi

2015-02-01

Urban environmental quality in brownfield redevelopment sites is of vital importance after most of former industrial areas were replanned or changed into residential and recreational areas. Hence, it is necessary to rethink if those brownfield redevelopment sites have been cleaned up so that there will be no negative health impacts to local residents. Under such a circumstance, this paper aims to evaluate the contamination level of heavy metals within a brownfield redevelopment site in China, namely, the Tiexi old industrial zone in Shenyang. Surface soil and dust samples were collected from local industrial sites, residential/commercial sites, traffic sites, and recreational sites, respectively. Our analysis results revealed that although the soils in the brownfield redevelopment sites had been treated and remediated, heavy metal pollution still exists in certain sites, especially in the current industrial sites that will be planned into residential/commercial or recreational zones, and the current residential sites where the former industrial sites located, showing that past industrial activities did and will continue to influence the soil quality. Further health risk assessment indicates that As and Pb generated from industrial sites and traffic sites has a potential to pose serious health risks to local residents, especially children. The hotspots with more serious health risks to children are mainly concentrated in the areas close to the former Shenyang Smelting Plant. After one decade of redevelopment, the Tiexi old industrial zone has become a new urban area which is not suitable for large-scaled soil remediation efforts. Thus, the phytoremediation by trees or herbs in heavy-metal-contaminated land is more appropriate and should be embedded into urban green land planning. This study provides innovative policy insights on urban brownfield redevelopment to both governmental officials and related stakeholders so that they can make appropriate remediation actions.

Work zone speed reduction utilizing dynamic speed signs

DOT National Transportation Integrated Search

2011-08-30

Vast quantities of transportation data are automatically recorded by intelligent transportations infrastructure, such as inductive loop detectors, video cameras, and side-fire radar devices. Such devices are typically deployed by traffic management c...

Speed management toolbox for rural communities.

DOT National Transportation Integrated Search

2013-04-01

The primary objective of this toolbox is to summarize various known traffic-calming treatments and their effectiveness. This toolbox focuses on roadway-based treatments for speed management, particularly for rural communities with transition zones. E...

Risk appraisal of passing zones on two-lane rural highways and policy applications.

PubMed

Mwesige, Godfrey; Farah, Haneen; Koutsopoulos, Haris N

2016-05-01

Passing on two-lane rural highways is associated with risks of head-on collision resulting from unsafe completion of passing maneuvers in the opposite traffic lane. In this paper, we explore the use of time-to-collision (TTC) as a surrogate safety measure of the risk associated with passing maneuvers. Logistic regression models to predict the probability to end the passing maneuver with TTC less than 2 or 3s-threshold were developed with the time-gap from initiation of the maneuver to arrival of the opposite vehicle (effective accepted gap), and the passing duration as explanatory variables. The data used for model estimation was collected using stationary tripod-mounted camcorders at 19 passing zones in Uganda. Results showed that passing maneuvers completed with TTC less than 3s are unsafe and often involved sudden speed reduction, flashing headlights, and lateral shift to shoulders. Model sensitivity analysis was conducted for observed passing durations involving passenger cars or short trucks (2-3 axles), and long trucks (4-7 axles) as the passed vehicles for 3s TTC-threshold. Three risk levels were proposed based on the probability to complete passing maneuvers with TTC less than 3s for a range of opposite direction traffic volumes. Applications of the results for safety improvements of two-lane rural highways are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Traffic analysis toolbox volume XI : weather and traffic analysis, modeling and simulation.

DOT National Transportation Integrated Search

2010-12-01

This document presents a weather module for the traffic analysis tools program. It provides traffic engineers, transportation modelers and decisions makers with a guide that can incorporate weather impacts into transportation system analysis and mode...

Satellite switched FDMA advanced communication technology satellite program

NASA Technical Reports Server (NTRS)

Atwood, S.; Higton, G. H.; Wood, K.; Kline, A.; Furiga, A.; Rausch, M.; Jan, Y.

1982-01-01

The satellite switched frequency division multiple access system provided a detailed system architecture that supports a point to point communication system for long haul voice, video and data traffic between small Earth terminals at Ka band frequencies at 30/20 GHz. A detailed system design is presented for the space segment, small terminal/trunking segment at network control segment for domestic traffic model A or B, each totaling 3.8 Gb/s of small terminal traffic and 6.2 Gb/s trunk traffic. The small terminal traffic (3.8 Gb/s) is emphasized, for the satellite router portion of the system design, which is a composite of thousands of Earth stations with digital traffic ranging from a single 32 Kb/s CVSD voice channel to thousands of channels containing voice, video and data with a data rate as high as 33 Mb/s. The system design concept presented, effectively optimizes a unique frequency and channelization plan for both traffic models A and B with minimum reorganization of the satellite payload transponder subsystem hardware design. The unique zoning concept allows multiple beam antennas while maximizing multiple carrier frequency reuse. Detailed hardware design estimates for an FDMA router (part of the satellite transponder subsystem) indicate a weight and dc power budget of 353 lbs, 195 watts for traffic model A and 498 lbs, 244 watts for traffic model B.

An open-terrain line source model coupled with street-canyon effects to forecast carbon monoxide at traffic roundabout.

PubMed

Pandian, Suresh; Gokhale, Sharad; Ghoshal, Aloke Kumar

2011-02-15

A double-lane four-arm roundabout, where traffic movement is continuous in opposite directions and at different speeds, produces a zone responsible for recirculation of emissions within a road section creating canyon-type effect. In this zone, an effect of thermally induced turbulence together with vehicle wake dominates over wind driven turbulence causing pollutant emission to flow within, resulting into more or less equal amount of pollutants upwind and downwind particularly during low winds. Beyond this region, however, the effect of winds becomes stronger, causing downwind movement of pollutants. Pollutant dispersion caused by such phenomenon cannot be described accurately by open-terrain line source model alone. This is demonstrated by estimating one-minute average carbon monoxide concentration by coupling an open-terrain line source model with a street canyon model which captures the combine effect to describe the dispersion at non-signalized roundabout. The results of the modeling matched well with the measurements compared with the line source model alone and the prediction error reduced by about 50%. The study further demonstrated this with traffic emissions calculated by field and semi-empirical methods. Copyright © 2010 Elsevier B.V. All rights reserved.

No-passing zone system: user's manual.

DOT National Transportation Integrated Search

2016-08-01

This Users Manual is intended for traffic engineers and technicians who will be either conducting passing sight distance : measurement runs in the field or processing the collected data in the office. This Users Manual includes: : - A descripti...

Evaluation of Automated Flagger Assistance Devices

DOT National Transportation Integrated Search

2018-02-01

Automated flagger assistance devices (AFADs) are designed to improve worker safety by replacing flaggers who are typically located near traffic approaching a work zone. In this study, a new AFAD developed by the Missouri Department of Transportation ...

Assessment of atmospheric metallic pollution in the metropolitan region of São Paulo, Brazil, employing Tillandsia usneoides L. as biomonitor.

PubMed

Figueiredo, A M G; Nogueira, C A; Saiki, M; Milian, F M; Domingos, M

2007-01-01

Tillandsia usneoides L. is an epiphytic bromeliad plant able to absorb water and nutrients directly from the air. For this reason this species was selected to carry out a monitoring study of air pollution in the metropolitan region of São Paulo, Brazil. Five consecutive transplantation experiments (8 weeks each) were performed in 10 sites of the city, submitted to different sources of air pollution (industrial, vehicular), using plants collected from an unpolluted area. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis. Traffic-related elements such as Zn and Ba presented high concentrations in exposure sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn and Co the highest contents were related to industrial zones and can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.

Analysis of the frequency and severity of rear-end crashes in work zones.

PubMed

Qi, Yi; Srinivasan, Raghavan; Teng, Hualiang; Baker, Robert

2013-01-01

The objective of this study was to identify the factors that influence the frequency and severity of rear-end crashes in work zones because rear-end crashes represent a significant proportion of crashes that occur in work zones. Truncated count data models were developed to identify influencing factors on the frequency of read-end crashes in work zones and ordered probit models were developed to evaluate influencing factors on the severity of rear-end crashes in work zones. Most of the variables identified in this study for these 2 models were significant at the 95 percent level. The statistics for models indicate that the 2 developed models are appropriate compared to alternative models. Major findings related to the frequency of rear-end crashes include the following: (1) work zones for capacity and pavement improvements have the highest frequency compared to other types of work zones; (2) work zones controlled by flaggers are associated with more rear-end crashes compared to those controlled by arrow boards; and (3) work zones with alternating one-way traffic tended to have more rear-end crashes compared to those with lane shifts. Major findings related to the severity of the rear-end crashes include the following: (1) rear-end crashes associated with alcohol, night, pedestrians, and roadway defects are more severe, and those associated with careless backing, stalled vehicles, slippery roadways, and misunderstanding flagging signals are less severe; (2) truck involvement and a large number of vehicles in a crash are both associated with increased severity, and (3) rear-end crashes that happened in work zones for bridge, capacity, and pavement are likely to be more severe than others.

23 CFR 772.11 - Analysis of traffic noise impacts.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

23 CFR 772.11 - Analysis of traffic noise impacts.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

23 CFR 772.11 - Analysis of traffic noise impacts.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Analysis of traffic noise impacts. 772.11 Section 772.11... PROCEDURES FOR ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.11 Analysis of traffic noise impacts. (a) The highway agency shall determine and analyze expected traffic noise impacts. (1) For...

Impact of traffic intensity and pavement aggregate size on road dust particles loading

NASA Astrophysics Data System (ADS)

Amato, F.; Pandolfi, M.; Alastuey, A.; Lozano, A.; Contreras González, J.; Querol, X.

2013-10-01

Road dust emissions severely hamper PM10 urban air quality and their burden is expected to increase relatively to primary motor exhaust emissions. Beside the large influence of climate and meteorology, the emission potential varies widely also from one road to another due to numerous factors such as traffic conditions, pavement type and external sources. Nevertheless none of these factors is sufficiently known for a reliable description in emission modelling and for decision making in air quality management. In this study we carried out intensive road dust measurement campaigns in South Spain, with the aim of investigating the relationship between emission potential (i.e. road dust load) and traffic intensity, pavement aggregate size and distance from braking zones. Results indicate that, while no impact from braking activity can be drawn on the bulk road dust mass, an increase in traffic intensity or mean pavement aggregate size clearly reduce the single vehicle emission potential.

The cost-effectiveness of mandatory 20 mph zones for the prevention of injuries.

PubMed

Peters, Jaime L; Anderson, Rob

2013-03-01

Traffic calming and speed limits are major public health strategies for further reducing road injuries, especially for vulnerable pedestrians such as children and the elderly. We conducted a cost-benefit analysis (CBA-favoured by transport economists) alongside a cost-utility analysis (CUA-favoured by health economists) of mandatory 20 mph zones, providing a unique opportunity to compare assumptions and results. A CUA from the public sector perspective and a CBA from a broader societal perspective. One-way, threshold and probabilistic sensitivity analyses were undertaken. In low casualty areas the intervention was not cost-effective regardless of approach (CUA: cost per QALY = £429 800; CBA: net present value = -£25 500). In high casualty areas, the intervention was cost-effective from the CBA (a saving of £90 600), but not from the CUA [cost per quality-adjusted life year (QALY) = £86 500; assuming National Institute for Health and Clinical Excellence's benchmark for approving health technologies]. Mandatory 20 mph zones may be cost-effective in high casualty areas when a CBA from a societal perspective is considered. Although CBA may appear, in principle, more appropriate, the quality, age or absence of reliable data for many parameters means that there is a great deal of uncertainty and the results should be interpreted with caution.

Priority, market-ready technologies and innovations list.

DOT National Transportation Integrated Search

2006-01-01

Telephone services for travelers provide real-time information about work zones, traffic incidents, and other causes of congestion. They allow travelers to make more informed decisions about their travel routes or modes and increase safety by helping...

Benefits and safety impact of night work-zone activities

DOT National Transportation Integrated Search

1984-10-01

Through a literature review and discussions with highway and transportation officials in several states, information was obtained on questions and concerns relating to the planning, safety, and traffic control aspects of night maintenance and constru...

Incorporating weather impacts in traffic estimation and prediction systems (TREPS)

DOT National Transportation Integrated Search

2009-09-01

This document provides quantitative benefits of using Intelligent Transportation Systems in highway construction and maintenance work zones. The technical report covers case study sites in the District of Columbia, Texas, Michigan, Arkansas, and Nort...

Reducing Runway Incursions: Can You Relate?

DOT National Transportation Integrated Search

1992-01-01

Side object detection systems (SODS) are collision warning systems which alert drivers to the presence of traffic alongside their vehicle within defined detection zones. The intent of SODS is to reduce collisions during lane changes and merging maneu...

Quantifying rockfall risk on roads in the Port Hills, Christchurch, New Zealand

NASA Astrophysics Data System (ADS)

Unterrader, Stefan; Fuchs, Sven

2016-04-01

The Canterbury earthquake sequence starting on 22 September 2010 triggered widespread mass movements in the Port Hills area of Christchurch, the largest agglomeration of New Zealand's South Island. The MW 6.2 Christchurch earthquake of 22 February 2011 in particular generated the largest ground motions ever recorded in New Zealand and as a result initiated several thousands of rockfalls. Over 6,000 boulders were released and mapped shortly after the event. The risk from rockfall to residents in the Port Hills was quantitatively assessed by the regulatory authorities in order to develop an adjusted land zoning policy. Apart from damaging residential buildings many of these boulders also hit several road sections across the Port Hills. Due to the inherent differences between identifying hazard and risk to people in static structures and in moving objects, a recently carried out risk assessment of rockfall was limited to exposed properties. However, given the importance of local road infrastructure for commuter traffic, local risk management strategies would clearly benefit from quantifying the threat of boulders endangering traffic lines. For this study, existing datasets describing the hazard including recently estimated frequency-magnitude bands for earthquakes and non-seismic triggering events, boulder production rates, boulder size distribution and associated run-out distances, were used. These data were provided by the Christchurch City Council's (CCC) GIS web service. A digital layer of the local road network as well as a detailed dataset of traffic counts was used for GIS analysis, and the probability of individuals being hit by boulders was calculated for each road segment that intersects one or more rockfall hazard zones. Finally, risk was computed. The method applied follows a state-of-the-art approach in risk assessment which is generally based on the risk equation defining risk as the probability of occurrence of an event times the expected loss. More specifically, both the annual collective risk and individual risk of being hit by rockfalls on the Port Hills traffic lines were calculated. Both risk terms were assessed by drawing on a well-established method originally developed for evaluating snow avalanche risk on high-alpine pass roads. In order to reflect the discontinuous distribution of rockfall across the hazard zone (i.e. boulders will only hit certain points or follow one specific run-out path compared to the typical snow avalanche run-out behaviour) the original risk equation was adjusted. Hence, (1) the annual collective risk as well as the individual risk of being hit by rockfalls when travelling on the local road network was quantified, (2) the temporal dynamics of most susceptible elements at risk (i.e. commuter traffic) were identified and related dynamics in risk were assessed, and (3) the specific case of waiting traffic and the associated increase in fatality risk compared to moving traffic was computed. The results of this study provide first insights in both the collective and individual rockfall fatality risk on important traffic lines across the Port Hills. Road sections that are most prone to rockfall hazard were clearly identified in high spatial resolution. Sensitivity analysis of main parameters showed that the decrease in seismic hazard expected over the next decades resulted in decreasing rockfall hazard and therefore decreasing fatality risk even if currently increasing traffic volumes will further rise. Furthermore, a closer look on the individual risk of commuters was addressing some of the challenges within the inherent static approach of the risk concept, namely the temporal dynamics in traffic flow. It was further shown that the main traffic line, Tunnel Road, is characterized by a strongly diurnal variability including two traffic peaks between 7 and 9 a.m. and around 5 to 6 p.m. Additionally, the influence of road blockage by boulders falling onto endangered road sections was also responsible for an increasing annual fatality risk of road users on most of the studied road sections. Several conceptual shortcomings in previous studies were addressing this issue, particularly with respect to simplifying assumptions repeatedly made during the risk computation. The results of this study highlight some of the most important aspects in this regard. Finally, the risk of being hit by rockfalls while travelling on the roads of the study area were compared to other risks faced (and tolerated) by the New Zealand citizens. The spatio-temporal dynamics in rockfall risk across the Port Hills road network clearly had shown the inherent limitations of any static risk assessment. Fatality numbers in the Port Hills were low during the 22 February 2011 event because the earthquake hit around noon and it is shown that similar ground shaking intensities occurring during rush hour are likely to cause several fatalities on the main transportation lines. These risks are further increased as traffic jams are very likely to form after extensive road blockage. In addition, rockfall hitting critical infrastructure not only pose fatality risk to people travelling along these lines but also affect the ability of emergency response teams to safely assess parts of the area which otherwise would be cut off. This temporal aspect has yet to be incorporated into local risk management strategies. The clear identification of the road segments most prone to boulder hits can serve the authorities as decision support for any future mitigation works.

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. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Understanding the topological characteristics and flow complexity of urban traffic congestion

NASA Astrophysics Data System (ADS)

Wen, Tzai-Hung; Chin, Wei-Chien-Benny; Lai, Pei-Chun

2017-05-01

For a growing number of developing cities, the capacities of streets cannot meet the rapidly growing demand of cars, causing traffic congestion. Understanding the spatial-temporal process of traffic flow and detecting traffic congestion are important issues associated with developing sustainable urban policies to resolve congestion. Therefore, the objective of this study is to propose a flow-based ranking algorithm for investigating traffic demands in terms of the attractiveness of street segments and flow complexity of the street network based on turning probability. Our results show that, by analyzing the topological characteristics of streets and volume data for a small fraction of street segments in Taipei City, the most congested segments of the city were identified successfully. The identified congested segments are significantly close to the potential congestion zones, including the officially announced most congested streets, the segments with slow moving speeds at rush hours, and the areas near significant landmarks. The identified congested segments also captured congestion-prone areas concentrated in the business districts and industrial areas of the city. Identifying the topological characteristics and flow complexity of traffic congestion provides network topological insights for sustainable urban planning, and these characteristics can be used to further understand congestion propagation.

23 CFR 630.1102 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-04-01

... zone fatalities and injuries to workers and road users by establishing minimum requirements and..., installation and maintenance of temporary traffic control devices, and use of uniformed law enforcement officers during construction, utility, and maintenance operations, and by requiring contract pay items to...

Evaluation of temporary ramp metering for work zones.

DOT National Transportation Integrated Search

2012-11-01

Ramp metering has been successfully implemented in many states to improve traffic operations on freeways. Studies have documented the positive mobility and safety benefits of ramp metering. However, there have been no studies on the use of ramp meter...

A field investigation of concrete patches containing pyrament blended concrete.

DOT National Transportation Integrated Search

1994-01-01

During roadway repairs, state highway officials try to minimize lane closure times. This reduces inconvenience to travelers, reduces traffic control needs, and helps minimize work zone accidents. For rapid repairs, materials that provide high early s...

Guidelines for the application of removeable rumble strips

DOT National Transportation Integrated Search

2006-08-01

This work was initiated to assess the viability of removable rumble strips as replacements for asphalt rumble strips, particularly in short term highway work zones. The two rumble strips tested were the Orange Rumble Strip from Advanced Traffic Marki...

Visual warning system for worker safety on roadside work-zones.

DOT National Transportation Integrated Search

2016-08-01

Growing traffic on US roadways and heavy construction machinery on road construction sites pose a critical safety : threat to construction workers. This report summarizes the design and development of a worker safety system using : Dedicated Short Ra...

77 FR 13525 - Safety Zone; Rocketts Red Glare Fireworks, Ancarrows Landing Park, James River, Richmond, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

... enclose a stamped, self-addressed postcard or envelope. We will consider all comments and material..., dangerous projectiles, and falling hot embers or other debris, vessel traffic will be temporarily restricted...

76 FR 38086 - Safety Zone; Labor Day Fireworks, Ancarrows Landing Park, James River, Richmond, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

... know that they reached the Facility, please enclose a stamped, self-addressed postcard or envelope. We... discharge of fireworks, dangerous projectiles, and falling hot embers or other debris, vessel traffic will...

Online Optimal Control of Connected Vehicles for Efficient Traffic Flow at Merging Roads

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rios-Torres, Jackeline; Malikopoulos, Andreas; Pisu, Pierluigi

2015-01-01

This paper addresses the problem of coordinating online connected vehicles at merging roads to achieve a smooth traffic flow without stop-and-go driving. We present a framework and a closed-form solution that optimize the acceleration profile of each vehicle in terms of fuel economy while avoiding collision with other vehicles at the merging zone. The proposed solution is validated through simulation and it is shown that coordination of connected vehicles can reduce significantly fuel consumption and travel time at merging roads.

Risk factors affecting the severity of traffic accidents at Shanghai river-crossing tunnel.

PubMed

Lu, Jian John; Xing, Yingying; Wang, Chen; Cai, Xiaonan

2016-01-01

With increasing traffic volume and urban development, increasing numbers of underground tunnels have been constructed to relieve conflict between strained land and heavy traffic. However, as more long tunnels are constructed, tunnel traffic safety is becoming increasingly serious. Thus, it is necessary to acquire their implications and impacts. This study examined 4,539 traffic accidents that have occurred in 14 Shanghai river-crossing tunnels for the period 2011-2012 and analyze the correlation between potential factors and accident injury severity. An ordered logit model was developed to examine the correlation between potential factors and accident injury severity. Results show that increased injury severity is associated with male drivers, drivers aged 65 years or older, accident time from midnight to dawn, weekends, wet road surface, goods vehicles, 3 or more vehicles, 4 or more lanes, middle speed limits (50-79 km/h), zone 3, extra-long tunnels (over 3,000 m), and maximum longitudinal gradient. This article aims to provide useful information for engineers to develop interventions and countermeasures to improve tunnel safety in China.

Diagnostic throughput factor analysis for en-route airspace and optimal aircraft trajectory generation based on capacity prediction and controller workload

NASA Astrophysics Data System (ADS)

Shin, Sanghyun

Today's National Airspace System (NAS) is approaching its limit to efficiently cope with the increasing air traffic demand. Next Generation Air Transportation System (NextGen) with its ambitious goals aims to make the air travel more predictable with fewer delays, less time sitting on the ground and holding in the air to improve the performance of the NAS. However, currently the performance of the NAS is mostly measured using delay-based metrics which do not capture a whole range of important factors that determine the quality and level of utilization of the NAS. The factors affecting the performance of the NAS are themselves not well defined to begin with. To address these issues, motivated by the use of throughput-based metrics in many areas such as ground transportation, wireless communication and manufacturing, this thesis identifies the different factors which majorly affect the performance of the NAS as demand (split into flight cancellation and flight rerouting), safe separation (split into conflict and metering) and weather (studied as convective weather) through careful comparison with other applications and performing empirical sensitivity analysis. Additionally, the effects of different factors on the NAS's performance are quantitatively studied using real traffic data with the Future ATM Concepts Evaluation Tool (FACET) for various sectors and centers of the NAS on different days. In this thesis we propose a diagnostic tool which can analyze the factors that have greater responsibility for regions of poor and better performances of the NAS. Based on the throughput factor analysis for en-route airspace, it was found that weather and controller workload are the major factors that decrease the efficiency of the airspace. Also, since resources such as air traffic controllers, infrastructure and airspace are limited, it is becoming increasingly important to use the available resources efficiently. To alleviate the impact of the weather and controller workload while optimally utilizing limited resources, various aircraft rerouting strategies for Air Traffic Management (ATM) have been proposed. However, the number of rerouting tools available to address these issues for the center-level and the National Airspace System (NAS) are relatively less compared with the tools for the sector-level and terminal airspace. Additionally, previous works consider the airspace containing the weather as no-fly zones instead of reduced-traffic zones and do not explicitly consider controller workload when generating aircraft trajectories to avoid the weather-affected airspace, thereby reducing the overall performance of the airspace. In this thesis, a new rerouting algorithm for the center-level airspace is proposed to address these problems by introducing a feedback loop connecting a tactical rerouting algorithm with a strategic rerouting algorithm using dynamic programming and a modified A* algorithm respectively. This helps reduce the computational cost significantly while safely handling a large number of aircraft. In summary, this thesis suggests the ways in which the NAS's performance can be further improved, thereby supporting various concepts envisioned by the Next Generation Air Transportation System (NextGen) and providing vital information which can be used for suitable economic and environmental advantages.

77 FR 19963 - Special Local Regulation and Security Zone: War of 1812 Bicentennial Commemoration, Port of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-03

...The Coast Guard proposes to adopt a temporary special local regulation and temporary security zones, during, and after the War of 1812 Bicentennial Commemoration events in the Port of Boston, Massachusetts, to be held between June 28, 2012 and July 6, 2012. These regulations are necessary to promote the safe navigation of vessels and the safety of life and property during the heavy volume of vessel traffic expected during this event.

Work zone traffic legislation in Texas

DOT National Transportation Integrated Search

1999-03-01

This report presents the findings from speed studies before and after implementation of the double-fine law in Texas, as well as citation and fine data from those study sites. Also included in the report is an assessment of other legislation that cou...

Use of positive protection in work zones : transportation synthesis.

DOT National Transportation Integrated Search

2017-05-01

The MnDOT Office of Traffic, Safety and Technology is developing a manual on the use of temporary barriers, truck-mounted attenuators and other types of positive protection devices as guidance for designers, construction workers and contractors. To s...

Highway traffic operations and freeway management : state-of-the-practice

DOT National Transportation Integrated Search

2003-03-01

This paper focuses on the proactive management of freeway facilities to balance the capacity of the transportation system and the prevailing demands and to respond to out-of-the-ordinary conditions (e.g., incidents, adverse weather, work zones, speci...

Use of Additional Lighting for Traffic Control and Speed Reduction in Work Zones

DOT National Transportation Integrated Search

2018-02-01

The Federal Highway Administration (FHWA) is seeking new approaches to the design of the next national long-distance travel study- advanced methods of capturing and analyzing travel data to support effective, defensible transportation decision-making...

77 FR 27156 - Safety Zone, Temporary Change for Recurring Fifth Coast Guard District Fireworks Displays...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... submit comments by mail and would like to know that they reached the Facility, please enclose a stamped... fireworks, dangerous projectiles, and falling hot embers or other debris, vessel traffic will be temporarily...

Study of school zones with traffic signals : final report, June 2009.

DOT National Transportation Integrated Search

2009-06-01

One of the most pressing and controversial problems faced by parents, school administrators, law enforcement and transportation professionals throughout the country is the safety of children on their way to and from school. To proactively address thi...

A Study on Urban Road Traffic Safety Based on Matter Element Analysis

PubMed Central

Hu, Qizhou; Zhou, Zhuping; Sun, Xu

2014-01-01

This paper examines a new evaluation of urban road traffic safety based on a matter element analysis, avoiding the difficulties found in other traffic safety evaluations. The issue of urban road traffic safety has been investigated through the matter element analysis theory. The chief aim of the present work is to investigate the features of urban road traffic safety. Emphasis was placed on the construction of a criterion function by which traffic safety achieved a hierarchical system of objectives to be evaluated. The matter element analysis theory was used to create the comprehensive appraisal model of urban road traffic safety. The technique was used to employ a newly developed and versatile matter element analysis algorithm. The matter element matrix solves the uncertainty and incompatibility of the evaluated factors used to assess urban road traffic safety. The application results showed the superiority of the evaluation model and a didactic example was included to illustrate the computational procedure. PMID:25587267

Traffic Driven Analysis of Cellular and WiFi Networks

ERIC Educational Resources Information Center

Paul, Utpal Kumar

2012-01-01

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

Advanced Traffic Management Systems (ATMS) research analysis database system

DOT National Transportation Integrated Search

2001-06-01

The ATMS Research Analysis Database Systems (ARADS) consists of a Traffic Software Data Dictionary (TSDD) and a Traffic Software Object Model (TSOM) for application to microscopic traffic simulation and signal optimization domains. The purpose of thi...

Impact of Transport Zone Number in Simulation Models on Cost-Benefit Analysis Results in Transport Investments

NASA Astrophysics Data System (ADS)

Chmielewski, Jacek

2017-10-01

Nowadays, feasibility studies need to be prepared for all planned transport investments, mainly those co-financed with UE grants. One of the fundamental aspect of feasibility study is the economic justification of an investment, evaluated in an area of so called cost-benefit analysis (CBA). The main goal of CBA calculation is to prove that a transport investment is really important for the society and should be implemented as economically efficient one. It can be said that the number of hours (PH - passengers hours) in trips and travelled kilometres (PK - passengers kilometres) are the most important for CBA results. The differences between PH and PK calculated for particular investment scenarios are the base for benefits calculation. Typically, transport simulation models are the best source for such data. Transport simulation models are one of the most powerful tools for transport network planning. They make it possible to evaluate forecast traffic volume and passenger flows in a public transport system for defined scenarios of transport and area development. There are many different transport models. Their construction is often similar, and they mainly differ in the level of their accuracy. Even models for the same area may differ in this matter. Typically, such differences come from the accuracy of supply side representation: road and public transport network representation. In many cases only main roads and a public transport network are represented, while local and service roads are eliminated as a way of reality simplification. This also enables a faster and more effective calculation process. On the other hand, the description of demand part of these models based on transport zones is often stable. Difficulties with data collection, mainly data on land use, resulted in the lack of changes in the analysed land division into so called transport zones. In this paper the author presents an influence of land division on the results of traffic analyses, and hence on CBA outcome. Moreover, the paper shows that the effectiveness of investments as represented in the results of cost-benefit analyses is strictly correlated to a transport model detail.

Macro-level vulnerable road users crash analysis: A Bayesian joint modeling approach of frequency and proportion.

PubMed

Cai, Qing; Abdel-Aty, Mohamed; Lee, Jaeyoung

2017-10-01

This study aims at contributing to the literature on pedestrian and bicyclist safety by building on the conventional count regression models to explore exogenous factors affecting pedestrian and bicyclist crashes at the macroscopic level. In the traditional count models, effects of exogenous factors on non-motorist crashes were investigated directly. However, the vulnerable road users' crashes are collisions between vehicles and non-motorists. Thus, the exogenous factors can affect the non-motorist crashes through the non-motorists and vehicle drivers. To accommodate for the potentially different impact of exogenous factors we convert the non-motorist crash counts as the product of total crash counts and proportion of non-motorist crashes and formulate a joint model of the negative binomial (NB) model and the logit model to deal with the two parts, respectively. The formulated joint model is estimated using non-motorist crash data based on the Traffic Analysis Districts (TADs) in Florida. Meanwhile, the traditional NB model is also estimated and compared with the joint model. The result indicates that the joint model provides better data fit and can identify more significant variables. Subsequently, a novel joint screening method is suggested based on the proposed model to identify hot zones for non-motorist crashes. The hot zones of non-motorist crashes are identified and divided into three types: hot zones with more dangerous driving environment only, hot zones with more hazardous walking and cycling conditions only, and hot zones with both. It is expected that the joint model and screening method can help decision makers, transportation officials, and community planners to make more efficient treatments to proactively improve pedestrian and bicyclist safety. Published by Elsevier Ltd.

Traffic operational evaluation of traffic impact analysis (TIA) case sites.

DOT National Transportation Integrated Search

2010-09-22

This report summarizes traffic operational evaluation of six select traffic impact analysis (TIA) case sites and the effectiveness of forecasting methods used in TIA studies. Six TIA case sites comprising 15 signalized intersections and 2 unsignalize...

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.

23 CFR 630.1016 - Compliance date.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Compliance date. 630.1016 Section 630.1016 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1016 Compliance date. States shall comply with all...

23 CFR 630.1016 - Compliance date.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 23 Highways 1 2012-04-01 2012-04-01 false Compliance date. 630.1016 Section 630.1016 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1016 Compliance date. States shall comply with all...

23 CFR 630.1016 - Compliance date.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Compliance date. 630.1016 Section 630.1016 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1016 Compliance date. States shall comply with all...

23 CFR 630.1016 - Compliance date.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Compliance date. 630.1016 Section 630.1016 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1016 Compliance date. States shall comply with all...

23 CFR 630.1016 - Compliance date.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Compliance date. 630.1016 Section 630.1016 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS PRECONSTRUCTION PROCEDURES Work Zone Safety and Mobility § 630.1016 Compliance date. States shall comply with all...

Evaluation of the effectiveness of a variable advisory speed system on queue mitigation in work zones.

DOT National Transportation Integrated Search

2011-04-01

Variable Advisory Speed Systems (VASS) provide drivers with advanced warning regarding traffic speeds downstream to help them make better decisions. Vehicle use on highways is increasing and the need to improve highways brings increased construction ...

Interaction between drilled shaft and mechanically stabilized earth (MSE) wall : technical report.

DOT National Transportation Integrated Search

2017-04-01

Drilled shafts are being constructed within the reinforced zone of mechanically stabilized earth (MSE) walls especially in the case of overpass bridges where the drilled shafts carry the bridge deck or traffic signs. The interaction between the drill...

Use of incentive/disincentive contracting to mitigate work zone traffic impacts.

DOT National Transportation Integrated Search

2012-11-01

Incentive/disincentive clauses (I/D) are designed to award payments to contractors if they complete work ahead of schedule and to deduct payments if they exceed the completion time. A previously unanswered question is, Did the costs of the actual ...

Design and Evaluation of a Dynamic Dilemma Zone System for a High Speed Rural Intersection : Research Summary

DOT National Transportation Integrated Search

2012-08-01

Improving traffic safety is a priority transportation issue. A tremendous amount of : resources has been invested on improving safety and efficiency at signalized : intersections. Although programs such as driver education, red-light camera : deploym...

Analysis of Malicious Traffic in Modbus/TCP Communications

NASA Astrophysics Data System (ADS)

Kobayashi, Tiago H.; Batista, Aguinaldo B.; Medeiros, João Paulo S.; Filho, José Macedo F.; Brito, Agostinho M.; Pires, Paulo S. Motta

This paper presents the results of our analysis about the influence of Information Technology (IT) malicious traffic on an IP-based automation environment. We utilized a traffic generator, called MACE (Malicious trAffic Composition Environment), to inject malicious traffic in a Modbus/TCP communication system and a sniffer to capture and analyze network traffic. The realized tests show that malicious traffic represents a serious risk to critical information infrastructures. We show that this kind of traffic can increase latency of Modbus/TCP communication and that, in some cases, can put Modbus/TCP devices out of communication.

Air pollution and allergic diseases

PubMed Central

Brandt, Eric B.; Biagini Myers, Jocelyn M.; Ryan, Patrick H.; Khurana Hershey, Gurjit K.

2015-01-01

Purpose of review Exposure to traffic-related air pollutants (TRAP) has been implicated in asthma development, persistence, and exacerbation. This exposure is highly significant because increasingly large segments of the population worldwide reside in zones that have high levels of TRAP (1), including children since schools are often located in high traffic pollution exposure areas. Recent findings Recent findings include epidemiologic and mechanistic studies that shed new light on the impact of traffic pollution on allergic diseases and the biology underlying this impact. In addition, new innovative methods to assess and quantify traffic pollution have been developed to assess exposure and identify vulnerable populations and individuals. Summary This review will summarize the most recent findings in each of these areas. These findings will have substantial impact on clinical practice and research by development of novel methods to quantify exposure and identify at-risk individuals, as well as mechanistic studies that identify new targets for intervention for individuals most adversely affected by TRAP exposure. PMID:26474340

Transforming GIS data into functional road models for large-scale traffic simulation.

PubMed

Wilkie, David; Sewall, Jason; Lin, Ming C

2012-06-01

There exists a vast amount of geographic information system (GIS) data that model road networks around the world as polylines with attributes. In this form, the data are insufficient for applications such as simulation and 3D visualization-tools which will grow in power and demand as sensor data become more pervasive and as governments try to optimize their existing physical infrastructure. In this paper, we propose an efficient method for enhancing a road map from a GIS database to create a geometrically and topologically consistent 3D model to be used in real-time traffic simulation, interactive visualization of virtual worlds, and autonomous vehicle navigation. The resulting representation provides important road features for traffic simulations, including ramps, highways, overpasses, legal merge zones, and intersections with arbitrary states, and it is independent of the simulation methodologies. We test the 3D models of road networks generated by our algorithm on real-time traffic simulation using both macroscopic and microscopic techniques.

Impacts of traffic emissions on atmospheric particulate nitrate and organics at a downwind site on the periphery of Guangzhou, China

NASA Astrophysics Data System (ADS)

Qin, Yi Ming; Tan, Hao Bo; Jie Li, Yong; Schurman, Misha I.; Li, Fei; Canonaco, Francesco; Prévôt, André S. H.; Chan, Chak K.

2017-09-01

Particulate matter (PM) pollution on the peripheries of Chinese megacities can be as serious as in cities themselves. Given the substantial vehicular emissions in inner-city areas, the direct transport of primary PM (e.g., black carbon and primary organics) and effective formation of secondary PM from precursors (e.g., NOx and volatile organic compounds) can contribute to PM pollution in buffer zones between cities. To investigate how traffic emissions in inner-city areas impact these adjacent buffer zones, a suite of real-time instruments were deployed in Panyu, downwind from central Guangzhou, from November to December 2014. Nitrate mass fraction was higher on high-PM days, with the average nitrate-to-sulfate ratio increasing from around 0.35 to 1.5 as the PM mass concentration increased from 10 to 160 µg m-3. Particulate nitrate was strongly correlated with excess ammonium (([NH4+] / [SO42-] - 1.5) × [SO42-]), with higher concentrations in December than in November due to lower temperatures. The organic mass fraction was the highest across all PM1 levels throughout the campaign. While organic aerosols (OA) were dominated by secondary organic aerosols (SOA = semi-volatile oxygenated organic aerosols + low-volatility oxygenated organic aerosols) as a campaign average, freshly emitted hydrocarbon-like organic aerosols (HOA) contributed up to 40 % of OA during high-OA periods, which typically occurred at nighttime and contributed 23.8 to 28.4 % on average. This was due to daytime traffic restrictions on heavy-duty vehicles in Guangzhou, and HOA almost increased linearly with total OA concentration. SOA increased as odd oxygen (Ox = O3 + NO2) increased during the day due to photochemistry. A combination of nighttime traffic emissions and daytime photochemistry contributed to the buildup of PM in Panyu. The mitigation of PM pollution in inner-city areas by reducing vehicular traffic can potentially improve air quality in peripheral areas.

MASH test 3-11 of the TxDOT portable type 2 PCTB with sign support assembly

DOT National Transportation Integrated Search

2010-01-01

Portable concrete traffic barriers (PCTBs) are commonly used in work zones or in temporary median : barrier applications. PCTBs are needed for separation and channelization of vehicle movement and for : worker protection. Signage is often necessary w...

Work zone variable speed limit systems: Effectiveness and system design issues.

DOT National Transportation Integrated Search

2010-03-01

Variable speed limit (VSL) systems have been used in a number of countries, particularly in Europe, as a method to improve flow and increase safety. VSLs use detectors to collect data on current traffic and/or weather conditions. Posted speed limits ...

Work zone variable speed limit systems : effectiveness and system design issues.

DOT National Transportation Integrated Search

2010-03-01

Variable speed limit (VSL) systems have been used in a number of countries, particularly in Europe, as a method to improve flow and increase safety. VSLs use detectors to collect data on current traffic and/or weather conditions. Posted speed limits ...

Evaluation of timber barricades and precast concrete traffic barriers for use in highway construction areas.

DOT National Transportation Integrated Search

1976-01-01

On August 15, 1975, the National Transportation Safety Board submitted a number of recommendations to the Administrator of the Federal Highway Administration and the Governor of Virginia regarding safety practices in the construction zone of I-495 in...

A smartphone-based prototype system for incident/work zone management driven by crowd-sourced data.

DOT National Transportation Integrated Search

2015-02-01

This project develops a smartphone-based prototype system that supplements the 511 system to improve its dynamic traffic : routing service to state highway users under non-recurrent congestion. This system will save considerable time to provide cruci...

Network-constrained spatio-temporal clustering analysis of traffic collisions in Jianghan District of Wuhan, China

PubMed Central

Fan, Yaxin; Zhu, Xinyan; Guo, Wei; Guo, Tao

2018-01-01

The analysis of traffic collisions is essential for urban safety and the sustainable development of the urban environment. Reducing the road traffic injuries and the financial losses caused by collisions is the most important goal of traffic management. In addition, traffic collisions are a major cause of traffic congestion, which is a serious issue that affects everyone in the society. Therefore, traffic collision analysis is essential for all parties, including drivers, pedestrians, and traffic officers, to understand the road risks at a finer spatio-temporal scale. However, traffic collisions in the urban context are dynamic and complex. Thus, it is important to detect how the collision hotspots evolve over time through spatio-temporal clustering analysis. In addition, traffic collisions are not isolated events in space. The characteristics of the traffic collisions and their surrounding locations also present an influence of the clusters. This work tries to explore the spatio-temporal clustering patterns of traffic collisions by combining a set of network-constrained methods. These methods were tested using the traffic collision data in Jianghan District of Wuhan, China. The results demonstrated that these methods offer different perspectives of the spatio-temporal clustering patterns. The weighted network kernel density estimation provides an intuitive way to incorporate attribute information. The network cross K-function shows that there are varying clustering tendencies between traffic collisions and different types of POIs. The proposed network differential Local Moran’s I and network local indicators of mobility association provide straightforward and quantitative measures of the hotspot changes. This case study shows that these methods could help researchers, practitioners, and policy-makers to better understand the spatio-temporal clustering patterns of traffic collisions. PMID:29672551

Formal Verification of Air Traffic Conflict Prevention Bands Algorithms

NASA Technical Reports Server (NTRS)

Narkawicz, Anthony J.; Munoz, Cesar A.; Dowek, Gilles

2010-01-01

In air traffic management, a pairwise conflict is a predicted loss of separation between two aircraft, referred to as the ownship and the intruder. A conflict prevention bands system computes ranges of maneuvers for the ownship that characterize regions in the airspace that are either conflict-free or 'don't go' zones that the ownship has to avoid. Conflict prevention bands are surprisingly difficult to define and analyze. Errors in the calculation of prevention bands may result in incorrect separation assurance information being displayed to pilots or air traffic controllers. This paper presents provably correct 3-dimensional prevention bands algorithms for ranges of track angle; ground speed, and vertical speed maneuvers. The algorithms have been mechanically verified in the Prototype Verification System (PVS). The verification presented in this paper extends in a non-trivial way that of previously published 2-dimensional algorithms.

Utilizing traffic simulation tools with MOVES and AERMOD

DOT National Transportation Integrated Search

2011-01-01

Overview: Quantify the emissions and fuel consumption associated with traffic congestion from Commercial Motor Vehicle (CMV) crashes Project Description Traffic Simulation Emissions Analysis Future Use with Dispersion Analysis

Transition Characteristic Analysis of Traffic Evolution Process for Urban Traffic Network

PubMed Central

Chen, Hong; Li, Yang

2014-01-01

The characterization of the dynamics of traffic states remains fundamental to seeking for the solutions of diverse traffic problems. To gain more insights into traffic dynamics in the temporal domain, this paper explored temporal characteristics and distinct regularity in the traffic evolution process of urban traffic network. We defined traffic state pattern through clustering multidimensional traffic time series using self-organizing maps and construct a pattern transition network model that is appropriate for representing and analyzing the evolution progress. The methodology is illustrated by an application to data flow rate of multiple road sections from Network of Shenzhen's Nanshan District, China. Analysis and numerical results demonstrated that the methodology permits extracting many useful traffic transition characteristics including stability, preference, activity, and attractiveness. In addition, more information about the relationships between these characteristics was extracted, which should be helpful in understanding the complex behavior of the temporal evolution features of traffic patterns. PMID:24982969

Implementation and testing of the travel time prediction system (TIPS) : final report, May 2001.

DOT National Transportation Integrated Search

2001-05-01

The Travel Time Prediction System (TIPS) is a portable automated system for predicting and displaying travel time for motorists in advance of and through freeway construction work zones, on a real-time basis. It collects real-time traffic flow data u...

Implementation and testing of the travel time prediction system (TIPS) : executive summary, May 2001.

DOT National Transportation Integrated Search

2001-05-01

The Travel Time Prediction System (TIPS) is a portable automated system for predicting and displaying travel time for motorists in advance of and through freeway construction work zones, on a real-time basis. It collects real-time traffic flow data u...

Enhancing and generalizing the two-level screening approach incorporating the Highway Safety Manual (HSM) methods, phase 2.

DOT National Transportation Integrated Search

2016-04-01

This project aims at developing a novel methodology to identify traffic safety hotspots and hot zones for at the macroscopic : and microscopic levels. In order to achieve these objectives, the following tasks were performed. The research team : follo...

14 CFR 99.49 - Hawaii ADIZ.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

14 CFR 99.49 - Hawaii ADIZ.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

14 CFR 99.49 - Hawaii ADIZ.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

14 CFR 99.49 - Hawaii ADIZ.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

14 CFR 99.49 - Hawaii ADIZ.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Hawaii ADIZ. 99.49 Section 99.49 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.49 Hawaii ADIZ. (a) Outer boundary. The area included in the irregular octagonal figure...

78 FR 4790 - Security Zone, Potomac and Anacostia Rivers; Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-23

... comprehensive port security regimes designed to safeguard human life, vessels, and waterfront facilities while... the need for immediate action, the restriction of vessel traffic is necessary to protect life... necessary to safeguard life and property on the navigable waters before, during, and after activities...

Determination of traffic intensity from camera images using image processing and pattern recognition techniques

NASA Astrophysics Data System (ADS)

Mehrübeoğlu, Mehrübe; McLauchlan, Lifford

2006-02-01

The goal of this project was to detect the intensity of traffic on a road at different times of the day during daytime. Although the work presented utilized images from a section of a highway, the results of this project are intended for making decisions on the type of intervention necessary on any given road at different times for traffic control, such as installation of traffic signals, duration of red, green and yellow lights at intersections, and assignment of traffic control officers near school zones or other relevant locations. In this project, directional patterns are used to detect and count the number of cars in traffic images over a fixed area of the road to determine local traffic intensity. Directional patterns are chosen because they are simple and common to almost all moving vehicles. Perspective vision effects specific to each camera orientation has to be considered, as they affect the size and direction of patterns to be recognized. In this work, a simple and fast algorithm has been developed based on horizontal directional pattern matching and perspective vision adjustment. The results of the algorithm under various conditions are presented and compared in this paper. Using the developed algorithm, the traffic intensity can accurately be determined on clear days with average sized cars. The accuracy is reduced on rainy days when the camera lens contains raindrops, when there are very long vehicles, such as trucks or tankers, in the view, and when there is very low light around dusk or dawn.

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

NASA Technical Reports Server (NTRS)

Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

1998-01-01

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

Concentrations and size distributions of fine aerosol particles measured at roof level in urban zone

NASA Astrophysics Data System (ADS)

Despiau, S.; Croci, D.

2007-05-01

During the experimental Field Experiments to Constrain Models of Atmospheric Pollution and Transport of Emissions (ESCOMPTE) campaign in June-July 2001, concentrations and size distributions of fine particles (14-722 nm) were measured at roof level in downtown Marseille (France). Part of the campaign was dedicated to the study of aerosol behavior in relation to strong photochemical events (which were identified as "IOP" days) and their regional modeling. The analysis of the concentration variations and the evolution of average diurnal size distribution showed that an "IOP day" is not characterized by a specific concentration or its variation, nor by a specific evolution of the average size distribution. The morning traffic rush is detected at roof level by a net increase in particle concentration over the whole size range measured, indicating a production of ultrafine particles by the traffic but also the raising to roof level of particles of the accumulation mode. The increase is observed about 1 hour after the traffic peak at street level, which is characterized by strong increases in NOx and CO concentrations. The corresponding flux of particles at roof level has been estimated around 3 × 104 cm-2 s-1. A specific signature characterized by a strong and rapid burst of concentration (factor 2 to 4 in 15 min) of particles between 25 and 50 nm, independent of the traffic source, has been detected on six occasions during the campaign. These events occur systematically around noon, in cases of strong radiation, low relative humidity, and common wind direction. Despite the high-diameter value of these particles, it is suggested that they could result from a specific "secondary aerosol process" event involving ozone, biogenic, and/or anthropogenic gas precursors like iodine and VOCs.

Development of a composite line source emission model for traffic interrupted microenvironments and its application in particle number emissions at a bus station

NASA Astrophysics Data System (ADS)

Wang, Lina; Jayaratne, Rohan; Heuff, Darlene; Morawska, Lidia

A composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. Hence, this model was able to quickly quantify the time spent in each segment within the considered zone, as well as the composition and position of the requisite segments based on the vehicle fleet information, which not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bi-directional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. Although the CLSE model is intended to be applied in traffic management and transport analysis systems for the evaluation of exposure, as well as the simulation of vehicle emissions in traffic interrupted microenvironments, the bus station model can also be used for the input of initial source definitions in future dispersion models.

Spatial correlation analysis of urban traffic state under a perspective of community detection

NASA Astrophysics Data System (ADS)

Yang, Yanfang; Cao, Jiandong; Qin, Yong; Jia, Limin; Dong, Honghui; Zhang, Aomuhan

2018-05-01

Understanding the spatial correlation of urban traffic state is essential for identifying the evolution patterns of urban traffic state. However, the distribution of traffic state always has characteristics of large spatial span and heterogeneity. This paper adapts the concept of community detection to the correlation network of urban traffic state and proposes a new perspective to identify the spatial correlation patterns of traffic state. In the proposed urban traffic network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding correlation of traffic state. Further, the process of community detection in the urban traffic network (named GWPA-K-means) is applied to analyze the spatial dependency of traffic state. The proposed method extends the traditional K-means algorithm in two steps: (i) redefines the initial cluster centers by two properties of nodes (the GWPA value and the minimum shortest path length); (ii) utilizes the weight signal propagation process to transfer the topological information of the urban traffic network into a node similarity matrix. Finally, numerical experiments are conducted on a simple network and a real urban road network in Beijing. The results show that GWPA-K-means algorithm is valid in spatial correlation analysis of traffic state. The network science and community structure analysis perform well in describing the spatial heterogeneity of traffic state on a large spatial scale.

A Model for Risk Analysis of Oil Tankers

NASA Astrophysics Data System (ADS)

Montewka, Jakub; Krata, Przemysław; Goerland, Floris; Kujala, Pentti

2010-01-01

The paper presents a model for risk analysis regarding marine traffic, with the emphasis on two types of the most common marine accidents which are: collision and grounding. The focus is on oil tankers as these pose the highest environmental risk. A case study in selected areas of Gulf of Finland in ice free conditions is presented. The model utilizes a well-founded formula for risk calculation, which combines the probability of an unwanted event with its consequences. Thus the model is regarded a block type model, consisting of blocks for the probability of collision and grounding estimation respectively as well as blocks for consequences of an accident modelling. Probability of vessel colliding is assessed by means of a Minimum Distance To Collision (MDTC) based model. The model defines in a novel way the collision zone, using mathematical ship motion model and recognizes traffic flow as a non homogeneous process. The presented calculations address waterways crossing between Helsinki and Tallinn, where dense cross traffic during certain hours is observed. For assessment of a grounding probability, a new approach is proposed, which utilizes a newly developed model, where spatial interactions between objects in different locations are recognized. A ship at a seaway and navigational obstructions may be perceived as interacting objects and their repulsion may be modelled by a sort of deterministic formulation. Risk due to tankers running aground addresses an approach fairway to an oil terminal in Sköldvik, near Helsinki. The consequences of an accident are expressed in monetary terms, and concern costs of an oil spill, based on statistics of compensations claimed from the International Oil Pollution Compensation Funds (IOPC Funds) by parties involved.

Negotiation Based Deconfliction in Air-traffic Control

DTIC Science & Technology

2008-01-15

specifying the object models and their location in the world. Skybox Layer is able to show any background textures behind the defined world in the...visual- ization. The skybox is constructed as a standard large cube, thus six textures are mapped to each of its side. No-flight Zones Layer gives

Air Quality Benefits of Nighttime Construction in Texas Non-Attainment Counties--Technical Report.

DOT National Transportation Integrated Search

2017-12-15

The practice of performing some work zone activities at night has existed in the United States since at least the 1960s. Night work is most commonly initiated where it is impractical to close traffic lanes on certain high-volume roadways during norma...

77 FR 60081 - Anchorages; Captain of the Port Puget Sound Zone, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

...: Docket Management Facility (M-30), U.S. Department of Transportation, West Building Ground Floor, Room..., call or email Mr. Mark Ashley, Director, Vessel Traffic Service Puget Sound, Waterways Management... when it is received at the Docket Management Facility. We recommend that you include your name and a...

A demonstration of expert systems applications in transportation engineering : volume III, evaluation of the prototype expert system TRANZ.

DOT National Transportation Integrated Search

1990-01-01

The validation and evaluation of an expert system for traffic control in highway work zones (TRANZ) is described. The stages in the evaluation process consisted of the following: revisit the experts, selectively distribute copies of TRANZ with docume...

49 CFR Appendix D to Part 222 - Determining Risk Levels

Code of Federal Regulations, 2012 CFR

2012-10-01

... collision probability. There are three formulas, one for each warning device category: 1. automatic gates... risk for all public highway-rail grade crossings that are part of a quiet zone. The Prediction Formulas (a) The Prediction Formulas were developed by DOT as a guide for allocating scarce traffic safety...

49 CFR Appendix D to Part 222 - Determining Risk Levels

Code of Federal Regulations, 2014 CFR

2014-10-01

... collision probability. There are three formulas, one for each warning device category: 1. automatic gates... risk for all public highway-rail grade crossings that are part of a quiet zone. The Prediction Formulas (a) The Prediction Formulas were developed by DOT as a guide for allocating scarce traffic safety...

49 CFR Appendix D to Part 222 - Determining Risk Levels

Code of Federal Regulations, 2013 CFR

2013-10-01

... collision probability. There are three formulas, one for each warning device category: 1. automatic gates... risk for all public highway-rail grade crossings that are part of a quiet zone. The Prediction Formulas (a) The Prediction Formulas were developed by DOT as a guide for allocating scarce traffic safety...

78 FR 1753 - Security Zone, Potomac and Anacostia Rivers; Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... immediate action, the restriction of vessel traffic is necessary to protect life, property and the... of the Port the ability to implement comprehensive port security regimes designed to safeguard human life, vessels, and waterfront facilities while still sustaining the flow of commerce. The Captain of...

76 FR 63841 - Security Zone; Potomac River, Georgetown Channel, Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

... safeguard human life, vessels, and waterfront facilities while still sustaining the flow of commerce. The... restriction of vessel traffic is necessary to protect life, property and the environment, therefore, a 30-day... to safeguard life, property, and the environment on or near the navigable waters. Discussion of Rule...

76 FR 51255 - Security Zone; Potomac River, Georgetown Channel, Washington, DC

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-18

... security regimes designed to safeguard human life, vessels, and waterfront facilities while still... restriction of vessel traffic is necessary to protect life, property and the environment, therefore, a 30-day... maritime safety and security in order to safeguard life, property, and the environment on or near the...

78 FR 54392 - Security Zone, Baltimore Harbor, Baltimore's Inner Harbor; Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-04

... restriction of vessel traffic is necessary to protect life, property and the environment, therefore, a 30-day... of the Port the ability to implement comprehensive port security regimes designed to safeguard human life, vessels, and waterfront facilities while still sustaining the flow of commerce. The Captain of...

77 FR 3118 - Security Zone; Choptank River and Cambridge Channel, Cambridge, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-23

... security regimes designed to safeguard human life, vessels, and waterfront facilities while still... restriction of vessel traffic is necessary to protect life, property and the environment, therefore, a 30-day... maritime safety and security in order to safeguard life, property, and the environment on or near the...

23 CFR 630.1108 - Work zone safety management measures and strategies.

Code of Federal Regulations, 2010 CFR

2010-04-01

... uniformed law enforcement officer and marked law enforcement vehicle in view of motorized traffic on a... and other contingencies. (e) Work Vehicles and Equipment. In addition to addressing risks to workers... contractor's choice of work scheduling and methodology; (6) For Lump Sum items, a contingency provision...

Traffic analysis and control using image processing

NASA Astrophysics Data System (ADS)

Senthilkumar, K.; Ellappan, Vijayan; Arun, A. R.

2017-11-01

This paper shows the work on traffic analysis and control till date. It shows an approach to regulate traffic the use of image processing and MATLAB systems. This concept uses computational images that are to be compared with original images of the street taken in order to determine the traffic level percentage and set the timing for the traffic signal accordingly which are used to reduce the traffic stoppage on traffic lights. They concept proposes to solve real life scenarios in the streets, thus enriching the traffic lights by adding image receivers like HD cameras and image processors. The input is then imported into MATLAB to be used. as a method for calculating the traffic on roads. Their results would be computed in order to adjust the traffic light timings on a particular street, and also with respect to other similar proposals but with the added value of solving a real, big instance.

Large-scale measurement and modeling of backbone Internet traffic

NASA Astrophysics Data System (ADS)

Roughan, Matthew; Gottlieb, Joel

2002-07-01

There is a brewing controversy in the traffic modeling community concerning how to model backbone traffic. The fundamental work on self-similarity in data traffic appears to be contradicted by recent findings that suggest that backbone traffic is smooth. The traffic analysis work to date has focused on high-quality but limited-scope packet trace measurements; this limits its applicability to high-speed backbone traffic. This paper uses more than one year's worth of SNMP traffic data covering an entire Tier 1 ISP backbone to address the question of how backbone network traffic should be modeled. Although the limitations of SNMP measurements do not permit us to comment on the fine timescale behavior of the traffic, careful analysis of the data suggests that irrespective of the variation at fine timescales, we can construct a simple traffic model that captures key features of the observed traffic. Furthermore, the model's parameters are measurable using existing network infrastructure, making this model practical in a present-day operational network. In addition to its practicality, the model verifies basic statistical multiplexing results, and thus sheds deep insight into how smooth backbone traffic really is.

Computer-Assisted Traffic Engineering Using Assignment, Optimal Signal Setting, and Modal Split

DOT National Transportation Integrated Search

1978-05-01

Methods of traffic assignment, traffic signal setting, and modal split analysis are combined in a set of computer-assisted traffic engineering programs. The system optimization and user optimization traffic assignments are described. Travel time func...

A Wavelet Analysis Approach for Categorizing Air Traffic Behavior

NASA Technical Reports Server (NTRS)

Drew, Michael; Sheth, Kapil

2015-01-01

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

Effect of current vehicle’s interruption on traffic stability in cooperative car-following theory

NASA Astrophysics Data System (ADS)

Zhang, Geng; Liu, Hui

2017-12-01

To reveal the impact of the current vehicle’s interruption information on traffic flow, a new car-following model with consideration of the current vehicle’s interruption is proposed and the influence of the current vehicle’s interruption on traffic stability is investigated through theoretical analysis and numerical simulation. By linear analysis, the linear stability condition of the new model is obtained and the negative influence of the current vehicle’s interruption on traffic stability is shown in the headway-sensitivity space. Through nonlinear analysis, the modified Korteweg-de Vries (mKdV) equation of the new model near the critical point is derived and it can be used to describe the propagating behavior of the traffic density wave. Finally, numerical simulation confirms the analytical results, which shows that the current vehicle’s interruption information can destabilize traffic flow and should be considered in real traffic.

Analysis of Child-related Road Traffic Accidents in Vietnam

NASA Astrophysics Data System (ADS)

Vu, Anh Tuan; Nguyen, Dinh Vinh Man

2018-04-01

In recent years, the number of road traffic accidents, fatalities and injuries have been decreasing, but the figures of children road traffic accidents have been increasing in Ho Chi Minh City of Vietnam. This fact strongly calls for implementing effective solutions to improve traffic safety for children by the local government. This paper presents the trends, patterns and causes of road traffic accidents involving children based on the analysis of road traffic accident data over the period 2010-2015 and the video-based observations of road traffic law violations at 15 typical school gates and 10 typical roads. The results could be useful for the city government to formulate solutions to effectively improve traffic safety for children in Ho Chi Minh City and other cities in Vietnam.

Right-\\0xADturn traffic volume adjustment in traffic signal warrant analysis : final report.

DOT National Transportation Integrated Search

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in : Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) : and SOLARIS. Right-turn traffic does not affect intersection performance i...

Right-­turn traffic volume adjustment in traffic signal warrant analysis : final report.

DOT National Transportation Integrated Search

2016-05-06

This report was based on the research project, Right-Turn Traffic Volume Adjustment in Traffic Signal Warrants, sponsored by the Nevada Department of Transportation (NDOT) and SOLARIS. Right-turn traffic does not affect intersection performance in th...

Spatial Resolution Requirements for Traffic-Related Air Pollutant Exposure Evaluations

PubMed Central

Batterman, Stuart; Chambliss, Sarah; Isakov, Vlad

2014-01-01

Vehicle emissions represent one of the most important air pollution sources in most urban areas, and elevated concentrations of pollutants found near major roads have been associated with many adverse health impacts. To understand these impacts, exposure estimates should reflect the spatial and temporal patterns observed for traffic-related air pollutants. This paper evaluates the spatial resolution and zonal systems required to estimate accurately intraurban and near-road exposures of traffic-related air pollutants. The analyses use the detailed information assembled for a large (800 km2) area centered on Detroit, Michigan, USA. Concentrations of nitrogen oxides (NOx) due to vehicle emissions were estimated using hourly traffic volumes and speeds on 9,700 links representing all but minor roads in the city, the MOVES2010 emission model, the RLINE dispersion model, local meteorological data, a temporal resolution of 1 hr, and spatial resolution as low as 10 m. Model estimates were joined with the corresponding shape files to estimate residential exposures for 700,000 individuals at property parcel, census block, census tract, and ZIP code levels. We evaluate joining methods, the spatial resolution needed to meet specific error criteria, and the extent of exposure misclassification. To portray traffic-related air pollutant exposure, raster or inverse distance-weighted interpolations are superior to nearest neighbor approaches, and interpolations between receptors and points of interest should not exceed about 40 m near major roads, and 100 m at larger distances. For census tracts and ZIP codes, average exposures are overestimated since few individuals live very near major roads, the range of concentrations is compressed, most exposures are misclassified, and high concentrations near roads are entirely omitted. While smaller zones improve performance considerably, even block-level data can misclassify many individuals. To estimate exposures and impacts of traffic-related pollutants accurately, data should be geocoded or estimated at the most-resolved spatial level; census tract and larger zones have little if any ability to represent intraurban variation in traffic-related air pollutant concentrations. These results are based on one of the most comprehensive intraurban modeling studies in the literature and results are robust. Recommendations address the value of dispersion models to portray spatial and temporal variation of air pollutants in epidemiology and other studies; techniques to improve accuracy and reduce the computational burden in urban scale modeling; the necessary spatial resolution for health surveillance, demographic, and pollution data; and the consequences of low resolution data in terms of exposure misclassification. PMID:25132794

Evaluation of the impacts of traffic states on crash risks on freeways.

PubMed

Xu, Chengcheng; Liu, Pan; Wang, Wei; Li, Zhibin

2012-07-01

The primary objective of this study is to divide freeway traffic flow into different states, and to evaluate the safety performance associated with each state. Using traffic flow data and crash data collected from a northbound segment of the I-880 freeway in the state of California, United States, K-means clustering analysis was conducted to classify traffic flow into five different states. Conditional logistic regression models using case-controlled data were then developed to study the relationship between crash risks and traffic states. Traffic flow characteristics in each traffic state were compared to identify the underlying phenomena that made certain traffic states more hazardous than others. Crash risk models were also developed for different traffic states to identify how traffic flow characteristics such as speed and speed variance affected crash risks in different traffic states. The findings of this study demonstrate that the operations of freeway traffic can be divided into different states using traffic occupancy measured from nearby loop detector stations, and each traffic state can be assigned with a certain safety level. The impacts of traffic flow parameters on crash risks are different across different traffic flow states. A method based on discriminant analysis was further developed to identify traffic states given real-time freeway traffic flow data. Validation results showed that the method was of reasonably high accuracy for identifying freeway traffic states. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Reduction of automobile traffic: urgent health promotion policy].

PubMed

Tapia Granados, J A

1998-03-01

During the last few decades, traffic injuries have become one of the leading causes of death and disability in the world. In urban areas, traffic congestion, noise, and emissions from motor vehicles produce subjective disturbances and detectable pathological effects. More than one billion people are exposed to harmful levels of environmental pollution. Because its combustion engine generates carbon dioxide (CO2), the automobile is one of the chief sources of the gases that are causing the greenhouse effect. The latter has already caused a rise in the average ambient temperature, and over the next decades it will predictable cause significant climatic changes whose consequences, though uncertain, are likely to be harmful and possibly catastrophic. Aside from the greenhouse effect, the relentless growth of parking zones, traffic, and the roadway infrastructure in urban and rural areas is currently one of the leading causes of environmental degradation. Urban development, which is nearly always "planned" around traffic instead of people, leads to a significant deterioration in the quality of life, while it also destroys the social fabric. Unlike the private automobile, public transportation, bicycles, and walking help reduce pollution, congestion, and traffic volume, as well as the morbidity and mortality resulting from injuries and ailments related to pollution. Non-automobile transportation also encourages physical activity--with its positive effect on general health--and helps reduce the greenhouse effect. The drop in traffic volume and the increased use of alternate means of transportation are thus an integrated health promotion policy which should become an inherent part of the movement for the promotion of healthy cities and of transportation policies and economic policy in general.

Analysis on the Correlation of Traffic Flow in Hainan Province Based on Baidu Search

NASA Astrophysics Data System (ADS)

Chen, Caixia; Shi, Chun

2018-03-01

Internet search data records user’s search attention and consumer demand, providing necessary database for the Hainan traffic flow model. Based on Baidu Index, with Hainan traffic flow as example, this paper conduct both qualitative and quantitative analysis on the relationship between search keyword from Baidu Index and actual Hainan tourist traffic flow, and build multiple regression model by SPSS.

77 FR 71531 - Special Local Regulation; Kelley's Island Swim, Lake Erie; Kelley's Island, Lakeside, OH

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-03

...-AA08 Special Local Regulation; Kelley's Island Swim, Lake Erie; Kelley's Island, Lakeside, OH AGENCY... part 100 by adding a Special Local Regulation within the Captain of the Port Detroit Zone. This... Swim. This special local regulated area is necessary to protect swimmers from vessel traffic. DATES...

77 FR 11434 - Safety Zone; Patapsco River, Northwest and Inner Harbors, Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-27

... and Historic Shrine in Baltimore, Maryland, and its return. This action will restrict vessel traffic... Historic Shrine, Baltimore, Maryland. After being turned-around, the USS CONSTELLATION will be returned to... of the historic sloop-of-war USS CONSTELLATION on May 25, 2012. This action is necessary to provide...

Children's Playgrounds and Everyday City Life of Childhood

ERIC Educational Resources Information Center

Filipova, Alexandra Gennadyevna; Syroed, Nadezhda Savvovna; Goncharova, Svetlana Vladimirovna

2016-01-01

Play areas of entertainment and development are new recourses for modern city children, but at the same time, they produce risks of road traffic accidents, deviation, social inequality and social exclusion. Playgrounds in city/town yards are free zones of children's pastime, where children communicate and play together. The aim of this article is…

23 CFR 630.1106 - Policy and procedures for work zone safety management.

Code of Federal Regulations, 2010 CFR

2010-04-01

... established in accordance with 23 CFR 630.1006, shall include the consideration and management of road user...; Exposure Control Measures to avoid or minimize worker exposure to motorized traffic and road user exposure... road users. (b) Agency processes, procedures, and/or guidance should be based on consideration of...

78 FR 9811 - Anchorages; Captain of the Port Puget Sound Zone, WA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... associated with this rulemaking. You may also visit the Docket Management Facility in Room W12-140 on the... Traffic Service Puget Sound, Waterways Management Division, Sector Puget Sound, Coast Guard; telephone 206... of Executive Order 13563. The Office of Management and Budget has not reviewed it under those orders...

78 FR 69524 - Preparation of an Environmental Impact Statement for High Capacity Transit Improvements for the...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-19

... intervening high-density residential and commercial areas of northeastern and central Marion County. This is... of 10th Street where the street is narrow and eastbound traffic volumes are low. The transit lanes... impact areas include: land use, zoning, potential displacements, parkland, economic development...

14 CFR 99.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Applicability. 99.1 Section 99.1... AND GENERAL OPERATING RULES SECURITY CONTROL OF AIR TRAFFIC General § 99.1 Applicability. (a) This... Identification Zone (ADIZ) designated in subpart B. (b) Except for §§ 99.7, 99.13, and 99.15 this subpart does...

Effect of Pokémon GO on incidence of fatal traffic injuries: a population-based quasi-experimental study using the national traffic collisions database in Japan.

PubMed

Ono, Sachiko; Ono, Yosuke; Michihata, Nobuaki; Sasabuchi, Yusuke; Yasunaga, Hideo

2017-10-12

Pokémon GO (Niantic Labs, released on 22 July 2016 in Japan) is an augmented reality game that gained huge popularity worldwide. Despite concern about Pokémon GO-related traffic collisions, the effect of playing Pokémon GO on the incidence of traffic injuries remains unknown. We performed a population-based quasi-experimental study using national data from the Institute for Traffic Accident Research and Data Analysis, Japan. The outcome was incidence of traffic injuries. Of 127 082 000 people in Japan, 886 fatal traffic injuries were observed between 1 June and 31 August in 2016. Regression discontinuity analysis showed a non-significant change in incidence of fatal traffic injuries after the Pokémon GO release (0.017 deaths per million, 95%CI -0.036 to 0.071). This finding was similar to that obtained from a difference-in-differences analysis. Effect of Pokémon GO on fatal traffic injuries may be negligible. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Visual traffic jam analysis based on trajectory data.

PubMed

Wang, Zuchao; Lu, Min; Yuan, Xiaoru; Zhang, Junping; van de Wetering, Huub

2013-12-01

In this work, we present an interactive system for visual analysis of urban traffic congestion based on GPS trajectories. For these trajectories we develop strategies to extract and derive traffic jam information. After cleaning the trajectories, they are matched to a road network. Subsequently, traffic speed on each road segment is computed and traffic jam events are automatically detected. Spatially and temporally related events are concatenated in, so-called, traffic jam propagation graphs. These graphs form a high-level description of a traffic jam and its propagation in time and space. Our system provides multiple views for visually exploring and analyzing the traffic condition of a large city as a whole, on the level of propagation graphs, and on road segment level. Case studies with 24 days of taxi GPS trajectories collected in Beijing demonstrate the effectiveness of our system.

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.

Assessing risk of navigational hazard from sea-level-related datum in the South West of Java Sea, Indonesia

NASA Astrophysics Data System (ADS)

Poerbandono

2017-07-01

This paper assesses the presence of navigational hazards due to underestimation of charted depths originated from an establishment of a sea-level-related reference plane, i.e. datum. The study domain is situated in one of Indonesia's densest marine traffic, SW Java Sea, Indonesia. The assessment is based on the comparison of the authorized Chart Datum (CD), being uniformly located at 0.6 m below Mean Sea Level (MSL), and a spatially varying Lowest Astronomical Tide (LAT) generated for the purpose of this research. Hazards are considered here as the deviation of LAT from CD and quantified as the ratio of LAT -CD deviation with respect to the allowable Total Vertical Uncertainty (TVU), i.e. the international standard for accuracy of depth information on nautical charts. Underestimation of charted depth is expected for the case that LAT falls below CD. Such a risk magnifies with decreasing depths, as well as the increasing volume of traffic and draught of the vessel. It is found that most of the domain is in the interior of risk-free zone from using uniform CD. As much as 0.08 and 0.19 parts of the area are in zones where the uncertainty of CD contributes respectively to 50% and 30% of Total Vertical Uncertainty. These are zones where the hazard of navigation is expected to increase due to underestimated lowest tidal level.

Impact of Land Use on PM2.5 Pollution in a Representative City of Middle China.

PubMed

Yang, Haiou; Chen, Wenbo; Liang, Zhaofeng

2017-04-26

Fine particulate matter (PM 2.5 ) pollution has become one of the greatest urban issues in China. Studies have shown that PM 2.5 pollution is strongly related to the land use pattern at the micro-scale and optimizing the land use pattern has been suggested as an approach to mitigate PM 2.5 pollution. However, there are only a few researches analyzing the effect of land use on PM 2.5 pollution. This paper employed land use regression (LUR) models and statistical analysis to explore the effect of land use on PM 2.5 pollution in urban areas. Nanchang city, China, was taken as the study area. The LUR models were used to simulate the spatial variations of PM 2.5 concentrations. Analysis of variance and multiple comparisons were employed to study the PM 2.5 concentration variances among five different types of urban functional zones. Multiple linear regression was applied to explore the PM 2.5 concentration variances among the same type of urban functional zone. The results indicate that the dominant factor affecting PM 2.5 pollution in the Nanchang urban area was the traffic conditions. Significant variances of PM 2.5 concentrations among different urban functional zones throughout the year suggest that land use types generated a significant impact on PM 2.5 concentrations and the impact did not change as the seasons changed. Land use intensity indexes including the building volume rate, building density, and green coverage rate presented an insignificant or counter-intuitive impact on PM 2.5 concentrations when studied at the spatial scale of urban functional zones. Our study demonstrates that land use can greatly affect the PM 2.5 levels. Additionally, the urban functional zone was an appropriate spatial scale to investigate the impact of land use type on PM 2.5 pollution in urban areas.

Impact of Land Use on PM2.5 Pollution in a Representative City of Middle China

PubMed Central

Yang, Haiou; Chen, Wenbo; Liang, Zhaofeng

2017-01-01

Fine particulate matter (PM2.5) pollution has become one of the greatest urban issues in China. Studies have shown that PM2.5 pollution is strongly related to the land use pattern at the micro-scale and optimizing the land use pattern has been suggested as an approach to mitigate PM2.5 pollution. However, there are only a few researches analyzing the effect of land use on PM2.5 pollution. This paper employed land use regression (LUR) models and statistical analysis to explore the effect of land use on PM2.5 pollution in urban areas. Nanchang city, China, was taken as the study area. The LUR models were used to simulate the spatial variations of PM2.5 concentrations. Analysis of variance and multiple comparisons were employed to study the PM2.5 concentration variances among five different types of urban functional zones. Multiple linear regression was applied to explore the PM2.5 concentration variances among the same type of urban functional zone. The results indicate that the dominant factor affecting PM2.5 pollution in the Nanchang urban area was the traffic conditions. Significant variances of PM2.5 concentrations among different urban functional zones throughout the year suggest that land use types generated a significant impact on PM2.5 concentrations and the impact did not change as the seasons changed. Land use intensity indexes including the building volume rate, building density, and green coverage rate presented an insignificant or counter-intuitive impact on PM2.5 concentrations when studied at the spatial scale of urban functional zones. Our study demonstrates that land use can greatly affect the PM2.5 levels. Additionally, the urban functional zone was an appropriate spatial scale to investigate the impact of land use type on PM2.5 pollution in urban areas. PMID:28445430

Analysis of traffic growth rates

DOT National Transportation Integrated Search

2001-08-01

The primary objectives of this study were to determine patterns of traffic flow and develop traffic growth rates by traffic composition and highway type for Kentucky's system of highways. Additional subtasks included the following: 1) a literature se...

Traffic information computing platform for big data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duan, Zongtao, E-mail: ztduan@chd.edu.cn; Li, Ying, E-mail: ztduan@chd.edu.cn; Zheng, Xibin, E-mail: ztduan@chd.edu.cn

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

Predictive Features of a Cockpit Traffic Display: A Workload Assessment

NASA Technical Reports Server (NTRS)

Wickens, Christopher D.; Morphew, Ephimia

1997-01-01

Eighteen pilots flew a series of traffic avoidance maneuvers in an experiment designed to assess the support offered and workload imposed by different levels of traffic display information in a free flight simulation. Three display prototypes were compared which differed in traffic information provided. A BASELINE (BL) display provided current and (2nd order) predicted information regarding ownship and current information of an intruder aircraft, represented on lateral and vertical displays in a coplanar suite. An INTRUDER PREDICTOR (IP) display, augmented the baseline display by providing lateral and vertical prediction of the intruder aircraft. A THREAT VECTOR (TV) display added to the IP display a vector that indicates the direction from ownship to the intruder at the predicted point of closest contact (POCC). The length of the vector corresponds to the radius of the protected zone, and the distance of the intersection of the vector with ownship predictor, corresponds to the time available till POCC or loss of separation. Pilots time shared the traffic avoidance task with a secondary task requiring them to monitor the top of the display for faint targets. This task simulated the visual demands of out-of-cockpit scanning, and hence was used to estimate the head-down time required by the different display formats. The results revealed that both display augmentations improved performance (safety) as assessed by predicted and actual loss of separation (i.e., penetration of the protected zone). Both enhancements also reduced workload, as assessed by the NASA TLX scale. The intruder predictor display produced these benefits with no substantial impact on the qualitative nature of the avoidance maneuvers that were selected. The threat vector produced the safety benefits by inducing a greater degree of (effective) lateral maneuvering, thus partially offsetting the benefits of reduced workload. The three displays did not differ in terms of their effect on performance of the monitoring task, used to infer head-down time, nor in the extent of vertical or airspeed maneuvering. The results are discussed in terms of their implications for 19 cognitive engineering design features.

An association between dietary habits and traffic accidents in patients with chronic liver disease: A data-mining analysis

PubMed Central

KAWAGUCHI, TAKUMI; SUETSUGU, TAKURO; OGATA, SHYOU; IMANAGA, MINAMI; ISHII, KUMIKO; ESAKI, NAO; SUGIMOTO, MASAKO; OTSUYAMA, JYURI; NAGAMATSU, AYU; TANIGUCHI, EITARO; ITOU, MINORU; ORIISHI, TETSUHARU; IWASAKI, SHOKO; MIURA, HIROKO; TORIMURA, TAKUJI

2016-01-01

The incidence of traffic accidents in patients with chronic liver disease (CLD) is high in the USA. However, the characteristics of patients, including dietary habits, differ between Japan and the USA. The present study investigated the incidence of traffic accidents in CLD patients and the clinical profiles associated with traffic accidents in Japan using a data-mining analysis. A cross-sectional study was performed and 256 subjects [148 CLD patients (CLD group) and 106 patients with other digestive diseases (disease control group)] were enrolled; 2 patients were excluded. The incidence of traffic accidents was compared between the two groups. Independent factors for traffic accidents were analyzed using logistic regression and decision-tree analyses. The incidence of traffic accidents did not differ between the CLD and disease control groups (8.8 vs. 11.3%). The results of the logistic regression analysis showed that yoghurt consumption was the only independent risk factor for traffic accidents (odds ratio, 0.37; 95% confidence interval, 0.16–0.85; P=0.0197). Similarly, the results of the decision-tree analysis showed that yoghurt consumption was the initial divergence variable. In patients who consumed yoghurt habitually, the incidence of traffic accidents was 6.6%, while that in patients who did not consume yoghurt was 16.0%. CLD was not identified as an independent factor in the logistic regression and decision-tree analyses. In conclusion, the difference in the incidence of traffic accidents in Japan between the CLD and disease control groups was insignificant. Furthermore, yoghurt consumption was an independent negative risk factor for traffic accidents in patients with digestive diseases, including CLD. PMID:27123257

An association between dietary habits and traffic accidents in patients with chronic liver disease: A data-mining analysis.

PubMed

Kawaguchi, Takumi; Suetsugu, Takuro; Ogata, Shyou; Imanaga, Minami; Ishii, Kumiko; Esaki, Nao; Sugimoto, Masako; Otsuyama, Jyuri; Nagamatsu, Ayu; Taniguchi, Eitaro; Itou, Minoru; Oriishi, Tetsuharu; Iwasaki, Shoko; Miura, Hiroko; Torimura, Takuji

2016-05-01

The incidence of traffic accidents in patients with chronic liver disease (CLD) is high in the USA. However, the characteristics of patients, including dietary habits, differ between Japan and the USA. The present study investigated the incidence of traffic accidents in CLD patients and the clinical profiles associated with traffic accidents in Japan using a data-mining analysis. A cross-sectional study was performed and 256 subjects [148 CLD patients (CLD group) and 106 patients with other digestive diseases (disease control group)] were enrolled; 2 patients were excluded. The incidence of traffic accidents was compared between the two groups. Independent factors for traffic accidents were analyzed using logistic regression and decision-tree analyses. The incidence of traffic accidents did not differ between the CLD and disease control groups (8.8 vs. 11.3%). The results of the logistic regression analysis showed that yoghurt consumption was the only independent risk factor for traffic accidents (odds ratio, 0.37; 95% confidence interval, 0.16-0.85; P=0.0197). Similarly, the results of the decision-tree analysis showed that yoghurt consumption was the initial divergence variable. In patients who consumed yoghurt habitually, the incidence of traffic accidents was 6.6%, while that in patients who did not consume yoghurt was 16.0%. CLD was not identified as an independent factor in the logistic regression and decision-tree analyses. In conclusion, the difference in the incidence of traffic accidents in Japan between the CLD and disease control groups was insignificant. Furthermore, yoghurt consumption was an independent negative risk factor for traffic accidents in patients with digestive diseases, including CLD.

Detection of traffic incidents using nonlinear time series analysis

NASA Astrophysics Data System (ADS)

Fragkou, A. D.; Karakasidis, T. E.; Nathanail, E.

2018-06-01

In this study, we present results of the application of nonlinear time series analysis on traffic data for incident detection. More specifically, we analyze daily volume records of Attica Tollway (Greece) collected from sensors located at various locations. The analysis was performed using the Recurrence Plot (RP) and Recurrence Quantification Analysis (RQA) method of the volume data of the lane closest to the median. The results show that it is possible to identify, through the abrupt change of the dynamics of the system revealed by RPs and RQA, the occurrence of incidents on the freeway and differentiate from recurrent traffic congestion. The proposed methodology could be of interest for big data traffic analysis.

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

NASA Technical Reports Server (NTRS)

Etheridge, Melvin; Plugge, Joana; Retina, Nusrat

1998-01-01

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

Zone clearance in an infinite TASEP with a step initial condition

NASA Astrophysics Data System (ADS)

Cividini, Julien; Appert-Rolland, Cécile

2017-06-01

The TASEP is a paradigmatic model of out-of-equilibrium statistical physics, for which many quantities have been computed, either exactly or by approximate methods. In this work we study two new kinds of observables that have some relevance in biological or traffic models. They represent the probability for a given clearance zone of the lattice to be empty (for the first time) at a given time, starting from a step density profile. Exact expressions are obtained for single-time quantities, while more involved history-dependent observables are studied by Monte Carlo simulation, and partially predicted by a phenomenological approach.

[Investigation of heavy metal and polycyclic aromatic hydrocarbons contamination in street dusts in urban Beijing].

PubMed

Xiang, Li; Li, Ying-Xia; Shi, Jiang-Hong; Liu, Jing-Ling

2010-01-01

This paper investigated the contamination levels of heavy metal and polycyclic aromatic hydrocarbons (PAHs) in street dusts in different functional areas in urban Beijing. Results show that the mean concentrations of Cd, Hg, Cr, Cu, Ni, Pb and Zn in street dusts in Beijing are 710 ng/g, 307 ng/g, 85.0 microg/g, 78.3 microg/g, 41.1 microg/g, 69.6 microg/g and 248.5 microg/g, respectively, which are significantly lower than those in most cities around the world and Shenyang, Shanghai in China. The mean concentration of Sigma 16PAHs in street dusts in Beijing is 0.398 microg/g, which is also lower than those of Handan, Tianjin and Shanghai. Non-parametric Friedman test demonstrates significant differences of heavy metal contents on street dusts from different functional zones. Street dusts in residential area and parks have lower heavy metal and PAHs concentrations than the street dusts from areas of high traffic density. The concentrations of heavy metals follow the order Zn > Cr > Cu > Pb > Ni > Cd > Hg, which is consistent with the situation in other cities around the world. The geoaccumulation index analysis shows that street dust in urban Beijing is moderately polluted by Cd, Zn and Cu, little polluted by Cr and Pb and practically unpolluted by Ni. The contamination levels of Sigma 16PAHs on street dusts vary greatly in different functional zones with parks little polluted, residential areas moderately to strongly polluted and traffic related areas strongly polluted to extremely polluted. Mass loading of heavy metals and PAHs is largely associated with street dusts of size range < 300 microm. Therefore, the urban sweeping vehicles should update the dust sweeping devices to remove not only the fine particle but also the coarser particles.

Ultrasonic Spot and Torsion Welding of Aluminum to Titanium Alloys: Process, Properties and Interfacial Microstructure

NASA Astrophysics Data System (ADS)

Balle, Frank; Magin, Jens

Hybrid lightweight structures shape the development of future vehicles in traffic engineering and the aerospace industry. For multi-material concepts made out of aluminum and titanium alloys, the ultrasonic welding technique is an alternative effective joining technology. The overlapped structures can be welded in the solid state, even without gas shielding. In this paper the conventional ultrasonic spot welding with longitudinal oscillation mode is compared to the recent ultrasonic torsion welding with a torsional mode at 20 kHz working frequency. For each technique the process parameters welding force, welding energy and oscillation amplitude were optimized for the hybrid joints using design of experiments. Relationships between the process parameters, mechanical properties and related welding zone should be understood. Central aspects of the research project are microscopic studies of the joining zone in cross section and extensive fracture surface analysis. Detailed electron microscopy and spectroscopy of the hybrid interface help to understand the interfacial formation during ultrasonic welding as well as to transfer the gained knowledge for further multi-metal joints.

Lead and cadmium concentrations in seawater and algae of the Tunisian coast.

PubMed

El Ati-Hellal, M; Hedhili, A; Hellal, F; Boujlel, K; Dachraoui, M; Bousnina, M; Ghorbel, H; Ndhif, M

2005-01-01

Both lead and cadmium are toxic trace metals, even in very weak concentrations. The aim of this study was to estimate lead and cadmium pollution in various sites of the Tunisian coast and to verify the possibility of modification of the algae bioconcentration power according to water physico-chemical conditions. Our study concerned 99 samples of algae and 99 samples of seawater, taken in different sites of the Tunisian littoral. The analysis was realized by atomic absorption spectrophotometry (oven graphite). In algae, Sfax site presented the highest concentrations of lead when Sousse site showed the lowest ones. In seawater, the most amounts of lead were observed in Bizerte, Mahdia and Sfax sites, and those of cadmium in Bizerte and Medenine coasts. Bizerte's coast seems to be the most exposed zone to pollution. Indeed, the intensification of sea traffic may take place on this pollution because hydrocarbons derived from petroleum contain some tetraethylic lead characterised by its great toxicity. Sousse's region is the least polluted zone; it might be due to the development of tourism and a strict regulation of pollution in this district.

Development and application of traffic flow information collecting and analysis system based on multi-type video

NASA Astrophysics Data System (ADS)

Lu, Mujie; Shang, Wenjie; Ji, Xinkai; Hua, Mingzhuang; Cheng, Kuo

2015-12-01

Nowadays, intelligent transportation system (ITS) has already become the new direction of transportation development. Traffic data, as a fundamental part of intelligent transportation system, is having a more and more crucial status. In recent years, video observation technology has been widely used in the field of traffic information collecting. Traffic flow information contained in video data has many advantages which is comprehensive and can be stored for a long time, but there are still many problems, such as low precision and high cost in the process of collecting information. This paper aiming at these problems, proposes a kind of traffic target detection method with broad applicability. Based on three different ways of getting video data, such as aerial photography, fixed camera and handheld camera, we develop a kind of intelligent analysis software which can be used to extract the macroscopic, microscopic traffic flow information in the video, and the information can be used for traffic analysis and transportation planning. For road intersections, the system uses frame difference method to extract traffic information, for freeway sections, the system uses optical flow method to track the vehicles. The system was applied in Nanjing, Jiangsu province, and the application shows that the system for extracting different types of traffic flow information has a high accuracy, it can meet the needs of traffic engineering observations and has a good application prospect.

23 CFR 772.17 - Traffic noise prediction.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Traffic noise prediction. 772.17 Section 772.17 Highways... ABATEMENT OF HIGHWAY TRAFFIC NOISE AND CONSTRUCTION NOISE § 772.17 Traffic noise prediction. (a) Any analysis required by this subpart must use the FHWA Traffic Noise Model (FHWA TNM), which is described in...

Study of air traffic over KLFIR

NASA Astrophysics Data System (ADS)

Nusyirwan, I. F.; Rohani, J. Mohd

2017-12-01

This paper shares the overview of the work currently being conducted with the Department of Civil Aviation Malaysia related to the air traffic. The aim is to study air traffic performance over KL and KK FIR, and the area of interest in this paper is the Kuala Lumpur Flight Information Region (KLFIR). The air traffic performance parameters includes general air traffic movement such as level allocation, number of movements, sector load analysis and also more specific parameters such as airborne delays, effects of weather to the air movements as well as ground delays. To achieve this, a huge effort has been undertaken that includes live data collection algorithm development and real time statistical analysis algorithm development. The main outcome from this multi-disciplinary work is the long-term analysis on the air traffic performance in Malaysia, which will put the country at par in the aviation community, namely the International Civil Aviation Organization (ICAO).

Wyoming Low-Volume Roads Traffic Volume Estimation

DOT National Transportation Integrated Search

2015-10-01

Low-volume roads are excluded from regular traffic counts except on a need to know basis. But needs for traffic volume data on low-volume roads in road infrastructure management, safety, and air quality analysis have necessitated regular traffic volu...

A hierarchical clustering scheme approach to assessment of IP-network traffic using detrended fluctuation analysis

NASA Astrophysics Data System (ADS)

Takuma, Takehisa; Masugi, Masao

2009-03-01

This paper presents an approach to the assessment of IP-network traffic in terms of the time variation of self-similarity. To get a comprehensive view in analyzing the degree of long-range dependence (LRD) of IP-network traffic, we use a hierarchical clustering scheme, which provides a way to classify high-dimensional data with a tree-like structure. Also, in the LRD-based analysis, we employ detrended fluctuation analysis (DFA), which is applicable to the analysis of long-range power-law correlations or LRD in non-stationary time-series signals. Based on sequential measurements of IP-network traffic at two locations, this paper derives corresponding values for the LRD-related parameter α that reflects the degree of LRD of measured data. In performing the hierarchical clustering scheme, we use three parameters: the α value, average throughput, and the proportion of network traffic that exceeds 80% of network bandwidth for each measured data set. We visually confirm that the traffic data can be classified in accordance with the network traffic properties, resulting in that the combined depiction of the LRD and other factors can give us an effective assessment of network conditions at different times.

Towards a Cloud Based Smart Traffic Management Framework

NASA Astrophysics Data System (ADS)

Rahimi, M. M.; Hakimpour, F.

2017-09-01

Traffic big data has brought many opportunities for traffic management applications. However several challenges like heterogeneity, storage, management, processing and analysis of traffic big data may hinder their efficient and real-time applications. All these challenges call for well-adapted distributed framework for smart traffic management that can efficiently handle big traffic data integration, indexing, query processing, mining and analysis. In this paper, we present a novel, distributed, scalable and efficient framework for traffic management applications. The proposed cloud computing based framework can answer technical challenges for efficient and real-time storage, management, process and analyse of traffic big data. For evaluation of the framework, we have used OpenStreetMap (OSM) real trajectories and road network on a distributed environment. Our evaluation results indicate that speed of data importing to this framework exceeds 8000 records per second when the size of datasets is near to 5 million. We also evaluate performance of data retrieval in our proposed framework. The data retrieval speed exceeds 15000 records per second when the size of datasets is near to 5 million. We have also evaluated scalability and performance of our proposed framework using parallelisation of a critical pre-analysis in transportation applications. The results show that proposed framework achieves considerable performance and efficiency in traffic management applications.

Development of a real-time crash risk prediction model incorporating the various crash mechanisms across different traffic states.

PubMed

Xu, Chengcheng; Wang, Wei; Liu, Pan; Zhang, Fangwei

2015-01-01

This study aimed to identify the traffic flow variables contributing to crash risks under different traffic states and to develop a real-time crash risk model incorporating the varying crash mechanisms across different traffic states. The crash, traffic, and geometric data were collected on the I-880N freeway in California in 2008 and 2009. This study considered 4 different traffic states in Wu's 4-phase traffic theory. They are free fluid traffic, bunched fluid traffic, bunched congested traffic, and standing congested traffic. Several different statistical methods were used to accomplish the research objective. The preliminary analysis showed that traffic states significantly affected crash likelihood, collision type, and injury severity. Nonlinear canonical correlation analysis (NLCCA) was conducted to identify the underlying phenomena that made certain traffic states more hazardous than others. The results suggested that different traffic states were associated with various collision types and injury severities. The matching of traffic flow characteristics and crash characteristics in NLCCA revealed how traffic states affected traffic safety. The logistic regression analyses showed that the factors contributing to crash risks were quite different across various traffic states. To incorporate the varying crash mechanisms across different traffic states, random parameters logistic regression was used to develop a real-time crash risk model. Bayesian inference based on Markov chain Monte Carlo simulations was used for model estimation. The parameters of traffic flow variables in the model were allowed to vary across different traffic states. Compared with the standard logistic regression model, the proposed model significantly improved the goodness-of-fit and predictive performance. These results can promote a better understanding of the relationship between traffic flow characteristics and crash risks, which is valuable knowledge in the pursuit of improving traffic safety on freeways through the use of dynamic safety management systems.

Automation Applications in an Advance Air Traffic Management System : Volume IIB : Functional Analysis of Air Traffic Management (Cont'd)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Traffic safety facts 1997 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

1998-11-01

In this annual report, Traffic Safety Facts 1997: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Traffic safety facts 2007 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2007-01-01

In this annual report, Traffic Safety Facts 2007: A Compilation of Motor Vehicle Crash Data from the Fatality : Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration : (NHTSA) presents descript...

Automated Applications in an Advanced Air Traffic Management System : Volume 2B. Functional Analysis of Air Traffic Management (Cont'd.)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Automation Applications in an Advanced Air Traffic Management System : Volume 2A. Functional Analysis of Air Traffic Management.

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Traffic safety facts 2008 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2008-01-01

In this annual report, Traffic Safety Facts 2008: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Traffic safety facts 2009 : a compilation of motor vehicle crash data from the fatality analysis reporting system and the general estimates system

DOT National Transportation Integrated Search

2009-01-01

In this annual report, Traffic Safety Facts 2009: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System, the National Highway Traffic Safety Administration (NHTSA) presents descriptive ...

Automation Applications in an Advanced Air Traffic Management System : Volume 2C. Functional Analysis of Air Traffic Management (Cont.'d)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Traffic pollution and countermeasures of urban traffic environment

NASA Astrophysics Data System (ADS)

He, Yuhong; Zheng, Chaocheng

2018-01-01

Background: Traffic environment has become a serious social problem in China currently, therefore, urban traffic environment governance is the requirement to solve this issue because as an important place in people's social life, urban traffic environment shows a strong city's energy. Objective: Based on analysis on social function of city traffic environment and its influence of traffic on urban environment in this paper, the goal to establish a healthy urban traffic environment must be included under the aim of sustainable development eternally and feasible measures were put forward afterwards. Method, result, conclusion and possible applications.

75 FR 18058 - Safety Zone; Patapsco River, Northwest and Inner Harbors, Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-09

... historic sloop-of-war USS CONSTELLATION on May 27, 2010. This action is necessary to provide for the safety... Baltimore, Maryland, to a point on the Patapsco River near the Fort McHenry National Monument and Historic Shrine in Baltimore, Maryland, and its return. This action will restrict vessel traffic in portions of...

77 FR 25592 - Safety Zone; Patapsco River, Northwest and Inner Harbors, Baltimore, MD

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-01

... historic sloop-of-war USS CONSTELLATION on May 24, 2012. This action is necessary to provide for the safety... Baltimore, Maryland, to a point on the Patapsco River near the Fort McHenry National Monument and Historic Shrine in Baltimore, Maryland, and its return. This action will restrict vessel traffic in portions of...

77 FR 27120 - Safety Zone; Virginia Beach Oceanfront Air Show, Atlantic Ocean, Virginia Beach, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-09

... restriction of vessel traffic is necessary to protect life, property and the environment during the fireworks... property and could cause significant injury or death to mariners observing the air shows. Due to the need... the Federal Register. The commenter suggested that the Coast Guard add a chart to the regulation to...

75 FR 33999 - Safety Zone; Fourth of July Fireworks Event, Cape Charles City Harbor, Cape Charles, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

...: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a 420-foot..., and falling hot embers or other debris, vessel traffic will be temporarily restricted within 420 feet... navigable waters of the Cape Charles City Harbor within the area bounded by a 420-foot radius circle...

33 CFR 150.915 - How are safety zones, no anchoring areas, and areas to be avoided established and modified?

Code of Federal Regulations, 2014 CFR

2014-07-01

... local conditions of geography, climate and other similar factors; (4) The need for granting exemptions for the installation and use of equipment or devices for use with vessel traffic services for certain... proximity of fishing grounds, oil and gas drilling and production operations, or other potential or actual...

33 CFR 150.915 - How are safety zones, no anchoring areas, and areas to be avoided established and modified?

Code of Federal Regulations, 2011 CFR

2011-07-01

... local conditions of geography, climate and other similar factors; (4) The need for granting exemptions for the installation and use of equipment or devices for use with vessel traffic services for certain... proximity of fishing grounds, oil and gas drilling and production operations, or other potential or actual...

33 CFR 150.915 - How are safety zones, no anchoring areas, and areas to be avoided established and modified?

Code of Federal Regulations, 2010 CFR

2010-07-01

... local conditions of geography, climate and other similar factors; (4) The need for granting exemptions for the installation and use of equipment or devices for use with vessel traffic services for certain... proximity of fishing grounds, oil and gas drilling and production operations, or other potential or actual...

33 CFR 150.915 - How are safety zones, no anchoring areas, and areas to be avoided established and modified?

Code of Federal Regulations, 2012 CFR

2012-07-01

... local conditions of geography, climate and other similar factors; (4) The need for granting exemptions for the installation and use of equipment or devices for use with vessel traffic services for certain... proximity of fishing grounds, oil and gas drilling and production operations, or other potential or actual...

33 CFR 150.915 - How are safety zones, no anchoring areas, and areas to be avoided established and modified?

Code of Federal Regulations, 2013 CFR

2013-07-01

... local conditions of geography, climate and other similar factors; (4) The need for granting exemptions for the installation and use of equipment or devices for use with vessel traffic services for certain... proximity of fishing grounds, oil and gas drilling and production operations, or other potential or actual...

Environmental Assessment: Sooner Drop Zone Expansion Altus Air Force Base, Oklahoma

DTIC Science & Technology

2003-08-01

AND OUTDOOR NOISE SOURCES NOISE LEVEL (dBA) COMMON INDOOR NOISE LEVELS COMMON OUTDOOR NOISE LEVELS Jet Flyover at 1000 ft. Gas Lawn Mower at 3 ft...Diesel Truck at 50 ft. Noise Urban Daytime Gas Lawn Mower at 100 ft. Commercial Area Heavy Traffic at 300 ft. Quiet Urban Daytime Quiet Urban Nighttime

Profile of non-fatal injuries due to road traffic accidents from a industrial town in India

PubMed Central

Bayan, Pankaj; Bhawalkar, J. S.; Jadhav, S. L.; Banerjee, Amitav

2013-01-01

Background: India has one of the highest road traffic accident rates in the world. To lessen this burden, information on the contributing factors is necessary. Materials and Methods: We studied a series of cases of non-fatal road traffic accidents in two tertiary care hospitals in Pimpri, Pune, India. A total of 212 non-fatal road traffic accidents admitted over a period of one year in these two hospitals constituted the study sample. The study variables were, the gender of the accident victims, mode of accident, days of week on which the accident took place, time of day when the injury was sustained, part of the body injured, nature of injury, and self-reported reasons for the accident. Statistical Analysis: data were summarized using percentages. The Chi-square test for goodness of fit was applied, to see whether there was any association between the different weekdays or time of day and the accidents. Results: Male : female ratio was almost 5 : 1, which was statistically significant (Chi-Square for goodness of fit = 95.11, df = 1, P < 0.0001). The maximum accidents occurred on Sundays and Mondays and the least around midweek (Wednesday). This pattern was also statistically significant (Chi-square for goodness of fit = 30.09, df = 6, P < 0.001). Pedestrians were the most vulnerable group, followed by drivers and pillions of two wheelers. These categories of road users contributed to almost 80% of the cases of Road Traffic Injuries (RTIs). Accidents were more likely in the time zone of 8 pm to midnight, followed by 4 pm to 8 pm (Chi-square for goodness of fit = 89.58, df = 5, P < 0.0001). A majority of the patients sustained multiple injuries followed by injuries to the lower limbs. A majority reported impaired visibility and fatigue as the cause of accident. Almost half (46.22%) of the injured admitted to drinking alcohol on a regular basis. Conclusion: Wide pavements and safe zebra crossings should be provided for pedestrians, as the highest casualty in this study were pedestrians. More accidents occurred on Sundays and Mondays and in the late evenings. Extra supervision by traffic police may be considered on Sundays / Holidays and the day following. Roads should be well lit to improve visibility after sunset. PMID:23724378

Making the Traffic Operations Case for Congestion Pricing: Operational Impacts of Congestion Pricing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chin, Shih-Miao; Hu, Patricia S; Davidson, Diane

2011-02-01

Congestion begins when an excess of vehicles on a segment of roadway at a given time, resulting in speeds that are significantly slower than normal or 'free flow' speeds. Congestion often means stop-and-go traffic. The transition occurs when vehicle density (the number of vehicles per mile in a lane) exceeds a critical level. Once traffic enters a state of congestion, recovery or time to return to a free-flow state is lengthy; and during the recovery process, delay continues to accumulate. The breakdown in speed and flow greatly impedes the efficient operation of the freeway system, resulting in economic, mobility, environmentalmore » and safety problems. Freeways are designed to function as access-controlled highways characterized by uninterrupted traffic flow so references to freeway performance relate primarily to the quality of traffic flow or traffic conditions as experienced by users of the freeway. The maximum flow or capacity of a freeway segment is reached while traffic is moving freely. As a result, freeways are most productive when they carry capacity flows at 60 mph, whereas lower speeds impose freeway delay, resulting in bottlenecks. Bottlenecks may be caused by physical disruptions, such as a reduced number of lanes, a change in grade, or an on-ramp with a short merge lane. This type of bottleneck occurs on a predictable or 'recurrent' basis at the same time of day and same day of week. Recurrent congestion totals 45% of congestion and is primarily from bottlenecks (40%) as well as inadequate signal timing (5%). Nonrecurring bottlenecks result from crashes, work zone disruptions, adverse weather conditions, and special events that create surges in demand and that account for over 55% of experienced congestion. Figure 1.1 shows that nonrecurring congestion is composed of traffic incidents (25%), severe weather (15%), work zones, (10%), and special events (5%). Between 1995 and 2005, the average percentage change in increased peak traveler delay, based on hours spent in traffic in a year, grew by 22% as the national average of hours spent in delay grew from 36 hours to 44 hours. Peak delay per traveler grew one-third in medium-size urban areas over the 10 year period. The traffic engineering community has developed an arsenal of integrated tools to mitigate the impacts of congestion on freeway throughput and performance, including pricing of capacity to manage demand for travel. Congestion pricing is a strategy which dynamically matches demand with available capacity. A congestion price is a user fee equal to the added cost imposed on other travelers as a result of the last traveler's entry into the highway network. The concept is based on the idea that motorists should pay for the additional congestion they create when entering a congested road. The concept calls for fees to vary according to the level of congestion with the price mechanism applied to make travelers more fully aware of the congestion externality they impose on other travelers and the system itself. The operational rationales for the institution of pricing strategies are to improve the efficiency of operations in a corridor and/or to better manage congestion. To this end, the objectives of this project were to: (1) Better understand and quantify the impacts of congestion pricing strategies on traffic operations through the study of actual projects, and (2) Better understand and quantify the impacts of congestion pricing strategies on traffic operations through the use of modeling and other analytical methods. Specifically, the project was to identify credible analytical procedures that FHWA can use to quantify the impacts of various congestion pricing strategies on traffic flow (throughput) and congestion.« less

Approaches to optimization of SS/TDMA time slot assignment. [satellite switched time division multiple access

NASA Technical Reports Server (NTRS)

Wade, T. O.

1984-01-01

Reduction techniques for traffic matrices are explored in some detail. These matrices arise in satellite switched time-division multiple access (SS/TDMA) techniques whereby switching of uplink and downlink beams is required to facilitate interconnectivity of beam zones. A traffic matrix is given to represent that traffic to be transmitted from n uplink beams to n downlink beams within a TDMA frame typically of 1 ms duration. The frame is divided into segments of time and during each segment a portion of the traffic is represented by a switching mode. This time slot assignment is characterized by a mode matrix in which there is not more than a single non-zero entry on each line (row or column) of the matrix. Investigation is confined to decomposition of an n x n traffic matrix by mode matrices with a requirement that the decomposition be 100 percent efficient or, equivalently, that the line(s) in the original traffic matrix whose sum is maximal (called critical line(s)) remain maximal as mode matrices are subtracted throughout the decomposition process. A method of decomposition of an n x n traffic matrix by mode matrices results in a number of steps that is bounded by n(2) - 2n + 2. It is shown that this upper bound exists for an n x n matrix wherein all the lines are maximal (called a quasi doubly stochastic (QDS) matrix) or for an n x n matrix that is completely arbitrary. That is, the fact that no method can exist with a lower upper bound is shown for both QDS and arbitrary matrices, in an elementary and straightforward manner.

Spatiotemporal characteristics of elderly population’s traffic accidents in Seoul using space-time cube and space-time kernel density estimation

PubMed Central

Cho, Nahye; Son, Serin

2018-01-01

The purpose of this study is to analyze how the spatiotemporal characteristics of traffic accidents involving the elderly population in Seoul are changing by time period. We applied kernel density estimation and hotspot analyses to analyze the spatial characteristics of elderly people’s traffic accidents, and the space-time cube, emerging hotspot, and space-time kernel density estimation analyses to analyze the spatiotemporal characteristics. In addition, we analyzed elderly people’s traffic accidents by dividing cases into those in which the drivers were elderly people and those in which elderly people were victims of traffic accidents, and used the traffic accidents data in Seoul for 2013 for analysis. The main findings were as follows: (1) the hotspots for elderly people’s traffic accidents differed according to whether they were drivers or victims. (2) The hourly analysis showed that the hotspots for elderly drivers’ traffic accidents are in specific areas north of the Han River during the period from morning to afternoon, whereas the hotspots for elderly victims are distributed over a wide area from daytime to evening. (3) Monthly analysis showed that the hotspots are weak during winter and summer, whereas they are strong in the hiking and climbing areas in Seoul during spring and fall. Further, elderly victims’ hotspots are more sporadic than elderly drivers’ hotspots. (4) The analysis for the entire period of 2013 indicates that traffic accidents involving elderly people are increasing in specific areas on the north side of the Han River. We expect the results of this study to aid in reducing the number of traffic accidents involving elderly people in the future. PMID:29768453

Spatiotemporal characteristics of elderly population's traffic accidents in Seoul using space-time cube and space-time kernel density estimation.

PubMed

Kang, Youngok; Cho, Nahye; Son, Serin

2018-01-01

The purpose of this study is to analyze how the spatiotemporal characteristics of traffic accidents involving the elderly population in Seoul are changing by time period. We applied kernel density estimation and hotspot analyses to analyze the spatial characteristics of elderly people's traffic accidents, and the space-time cube, emerging hotspot, and space-time kernel density estimation analyses to analyze the spatiotemporal characteristics. In addition, we analyzed elderly people's traffic accidents by dividing cases into those in which the drivers were elderly people and those in which elderly people were victims of traffic accidents, and used the traffic accidents data in Seoul for 2013 for analysis. The main findings were as follows: (1) the hotspots for elderly people's traffic accidents differed according to whether they were drivers or victims. (2) The hourly analysis showed that the hotspots for elderly drivers' traffic accidents are in specific areas north of the Han River during the period from morning to afternoon, whereas the hotspots for elderly victims are distributed over a wide area from daytime to evening. (3) Monthly analysis showed that the hotspots are weak during winter and summer, whereas they are strong in the hiking and climbing areas in Seoul during spring and fall. Further, elderly victims' hotspots are more sporadic than elderly drivers' hotspots. (4) The analysis for the entire period of 2013 indicates that traffic accidents involving elderly people are increasing in specific areas on the north side of the Han River. We expect the results of this study to aid in reducing the number of traffic accidents involving elderly people in the future.

NOx profile around a signalized intersection of busy roadway

NASA Astrophysics Data System (ADS)

Kim, Kyung Hwan; Lee, Seung-Bok; Woo, Sung Ho; Bae, Gwi-Nam

2014-11-01

The NOx pollution profile around a signalized intersection of a busy roadway was investigated to understand the effect of traffic control on urban air pollution. Traffic flow patterns were classified into three categories of quasi-cruising, a combination of deceleration and acceleration, and a combination of deceleration, idling, and acceleration. The spatial distribution of air pollution levels around an intersection could be represented as a quasi-normal distribution, whose peak height was aggravated by increased emissions due to transient driving patterns. The peak concentration of NOx around the signalized intersection for the deceleration, idling, and acceleration category was five times higher than that for the quasi-cruising category. Severe levels of NOx pollution tailed off approximately 400 m from the center of the intersection. Approximately 200-1000 ppb of additional NOx was observed when traffic was decelerating, idling, and accelerating within the intersection zone, resulting in high exposure levels for pedestrians around the intersection. We propose a fluctuating horizontal distribution of motor vehicle-induced air pollutants as a function of time.

LINEBACkER: Bio-inspired Data Reduction Toward Real Time Network Traffic Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teuton, Jeremy R.; Peterson, Elena S.; Nordwall, Douglas J.

Abstract—One essential component of resilient cyber applications is the ability to detect adversaries and protect systems with the same flexibility adversaries will use to achieve their goals. Current detection techniques do not enable this degree of flexibility because most existing applications are built using exact or regular-expression matching to libraries of rule sets. Further, network traffic defies traditional cyber security approaches that focus on limiting access based on the use of passwords and examination of lists of installed or downloaded programs. These approaches do not readily apply to network traffic occurring beyond the access control point, and when the datamore » in question are combined control and payload data of ever increasing speed and volume. Manual analysis of network traffic is not normally possible because of the magnitude of the data that is being exchanged and the length of time that this analysis takes. At the same time, using an exact matching scheme to identify malicious traffic in real time often fails because the lists against which such searches must operate grow too large. In this work, we introduce an alternative method for cyber network detection based on similarity-measuring algorithms for gene sequence analysis. These methods are ideal because they were designed to identify similar but nonidentical sequences. We demonstrate that our method is generally applicable to the problem of network traffic analysis by illustrating its use in two different areas both based on different attributes of network traffic. Our approach provides a logical framework for organizing large collections of network data, prioritizing traffic of interest to human analysts, and makes it possible to discover traffic signatures without the bias introduced by expert-directed signature generation. Pattern recognition on reduced representations of network traffic offers a fast, efficient, and more robust way to detect anomalies.« less

Prototype demonstration of a geographic information system application for seasonal analysis of traffic data : development of seasonal factors and seasonal adjustment of roadways

DOT National Transportation Integrated Search

1999-08-15

The Traffic Survey Unit plans to establish a methodology in which it can assign each Portable Traffic Counter (PTC) station a seasonal group profile through a means of statistical and geographical analysis. An ArcView Geographic Information Systems a...

Predicting Information Flows in Network Traffic.

ERIC Educational Resources Information Center

Hinich, Melvin J.; Molyneux, Robert E.

2003-01-01

Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

Analysis of pilot response time to time-critical air traffic control calls

DOT National Transportation Integrated Search

1991-08-01

One of the most important time-critical air traffic control messages for a pilot is one : that required an immediate maneuver for traffic avoidance. This study examines the time : required for an air traffic controller to successfully transmit such a...

Geosynchronous platform definition study. Volume 4, Part 2: Traffic analysis and system requirements for the new traffic model

NASA Technical Reports Server (NTRS)

1973-01-01

A condensed summary of the traffic analyses and systems requirements for the new traffic model is presented. The results of each study activity are explained, key analyses are described, and important results are highlighted.

A multi-site analysis of the association between black carbon concentrations and vehicular idling, traffic, background pollution, and meteorology during school dismissals.

PubMed

Richmond-Bryant, J; Bukiewicz, L; Kalin, R; Galarraga, C; Mirer, F

2011-05-01

A study was performed to assess the relationship between black carbon (BC), passing traffic, and vehicular idling outside New York City (NYC) schools during student dismissal. Monitoring was performed at three school sites in East Harlem, the Bronx, and Brooklyn for 1month per year over a two-year period from November 2006-October 2008. Monitoring at each site was conducted before and after the Asthma Free School Zone (AFSZ) asthma reduction education program was administered. Real-time equipment with a one-minute averaging interval was used to obtain the BC data, while volume counts of idling and passing school busses, trucks, and automobiles were collected each minute by study staff. These data were matched to ambient PM(2.5) and meteorology data obtained from the New York State Department of Environmental Conservation. A generalized additive model (GAM) model was run to examine the relationship between BC concentration and each variable while accounting for site-to-site differences. F-tests were employed to assess the significance of each of the predictor variables. The model results suggested that variability in ambient PM(2.5) concentration contributed 24% of the variability in transformed BC concentration, while variability in the number of idling busses and trucks on the street during dismissal contributed 20% of the variability in transformed BC concentration. The results of this study suggest that a combination of urban scale and local traffic control approaches in combination with cessation of school bus idling will produce improved local BC concentration outside schools. Published by Elsevier B.V.

An extended lattice model accounting for traffic jerk

NASA Astrophysics Data System (ADS)

Redhu, Poonam; Siwach, Vikash

2018-02-01

In this paper, a flux difference lattice hydrodynamics model is extended by considering the traffic jerk effect which comes due to vehicular motion of non-motor automobiles. The effect of traffic jerk has been examined through linear stability analysis and shown that it can significantly enlarge the unstable region on the phase diagram. To describe the phase transition of traffic flow, mKdV equation near the critical point is derived through nonlinear stability analysis. The theoretical findings have been verified using numerical simulation which confirms that the jerk parameter plays an important role in stabilizing the traffic jam efficiently in sensing the flux difference of leading sites.

Traffic analysis toolbox volume XIII : integrated corridor management analysis, modeling, and simulation guide

DOT National Transportation Integrated Search

2017-02-01

As part of the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII), this guide was designed to help corridor stakeholders implement the Integrated Corridor Management (ICM) Analysis, Modeling, and Simulation (AMS) methodology...

Traffic analysis toolbox volume XIII : integrated corridor management analysis, modeling, and simulation guide.

DOT National Transportation Integrated Search

2017-02-01

As part of the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII), this guide was designed to help corridor stakeholders implement the Integrated Corridor Management (ICM) Analysis, Modeling, and Simulation (AMS) methodology...

Identifying significant predictors of head-on conflicts on two-lane rural roads using inductive loop detectors data.

PubMed

Shariat-Mohaymany, Afshin; Tavakoli-Kashani, Ali; Nosrati, Hadi; Ranjbari, Andisheh

2011-12-01

To identify the significant factors that influence head-on conflicts resulting from dangerous overtaking maneuvers on 2-lane rural roads in Iran. A traffic conflict technique was applied to 12 two-lane rural roads in order to investigate the potential situations for accidents to occur and thus to identify the geometric and traffic factors affecting traffic conflicts. Traffic data were collected via the inductive loop detectors installed on these roads, and geometric characteristics were obtained through field observations. Two groups of data were then analyzed independently by Pearson's chi-square test to evaluate their relationship to traffic conflicts. The independent variables were percentage of time spent following (PTSF), percentage of heavy vehicles, directional distribution of traffic (DDT), mean speed, speed standard deviation, section type, road width, longitudinal slope, holiday or workday, and lighting condition. It was indicated that increasing the PTSF, decreasing the percentage of heavy vehicles, increasing the mean speed (up to 75 km/h), increasing DDT in the range of 0 to 60 percent, and decreasing the standard deviation of speed significantly increased the occurrence of traffic conflicts. It was also revealed that traffic conflicts occur more frequently on curve sections and on workdays. The variables road width, slope, and lighting condition were found to have a minor effect on conflict occurrence. To reduce the number of head-on conflicts on the aforementioned roads, some remedial measures are suggested, such as not constructing long "No Passing" zones and constructing passing lanes where necessary; keeping road width at the standard value; constructing roads with horizontal curves and a high radius and using appropriate road markings and overtaking-forbidden signs where it is impossible to modify the radius; providing enough light and installing caution signs/devices on the roads; and intensifying police control and supervision on workdays, especially in peak hours.

Factor Analysis of Traffic Safety in Urban Roads Based on FTA-LEC

NASA Astrophysics Data System (ADS)

Shuicheng, TIAN; Xingbo, YANG; Xiaoqing, SHEN; Detao, ZHANG

2018-05-01

In order to reduce the number and the loss of urban road traffic accidents in our country, improve the safety of road traffic, a statistical analysis of the research report on major road traffic accidents in 2016 was conducted. The risk factors affecting urban road traffic in China were analyzed by using FTA to find the basic hidden events. Secondly, the risk value of the identified hidden danger events were calculated and classified into four levels I, II, III and IV through the LEC evaluation method. Finally, the graded results of risk factors are verified through a case of specific accidents in Beijing. The results show that: the case verified the scientificalness and effectiveness of hazard classification and provided guidance for urban road traffic management.

Final report on the analyses of traffic accidents : Fast-Trac--phase 3, deliverable. Semi-annual reports on total accidents : trends, types and analysis of before and after studies

DOT National Transportation Integrated Search

1996-12-01

This report contains the results of an analysis of : traffic accidents in the City of Troy, Michigan, where : the Sydney Coordinated Adaptive Traffic System : (SCATS) was deployed as part of a federal demonstration : program. The analyses includes a ...

Streamlining Transportation Corridor Planning Processess: Freight and Traffic Information

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franzese, Oscar

2010-08-01

The traffic investigation is one of the most important parts of an Environmental Impact Statement of projects involving the construction of new roadway facilities and/or the improvement of existing ones. The focus of the traffic analysis is on the determination of anticipated traffic flow characteristics of the proposed project, by the application of analytical methods that can be grouped under the umbrella of capacity analysis methodologies. In general, the main traffic parameter used in EISs to describe the quality of traffic flow is the Level of Service (LOS). The current state of the practice in terms of the traffic investigationsmore » for EISs has two main shortcomings. The first one is related to the information that is necessary to conduct the traffic analysis, and specifically to the lack of integration among the different transportation models and the sources of information that, in general, reside in GIS databases. A discussion of the benefits of integrating CRS&SI technologies and the transportation models used in the EIS traffic investigation is included. The second shortcoming is in the presentation of the results, both in terms of the appearance and formatting, as well as content. The presentation of traffic results (current and proposed) is discussed. This chapter also addresses the need of additional data, in terms of content and coverage. Regarding the former, other traffic parameters (e.g., delays) that are more meaningful to non-transportation experts than LOS, as well as additional information (e.g., freight flows) that can impact traffic conditions and safety are discussed. Spatial information technologies can decrease the negative effects of, and even eliminate, these shortcomings by making the relevant information that is input to the models more complete and readily available, and by providing the means to communicate the results in a more clear and efficient manner. The benefits that the application and use of CRS&SI technologies can provide to improve and expedite the traffic investigation part of the EIS process are presented.« less

75 FR 26648 - Safety Zones; May Fireworks Displays Within the Captain of the Port Puget Sound Area of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

... traffic is necessary to protect life, property and the environment. Discussion of Rule The U.S. Coast... Responsibility (AOR) AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The U.S Coast Guard is... necessary to provide for the safety of life on navigable waters during the fireworks displays. Entry into...

Net profits.

PubMed

Menduno, M

1999-03-01

As Web traffic surges, health care has become a speed zone all its own. Sixth in Internet content, health sites draw two-thirds of all online users at least once. That's set off a race among the developers of specialized hubs aiming to organize it all--and cash in. "It's a land grab," says one player. "All of a sudden everyone woke up and said, 'We gotta do this.'"

Effectiveness of maritime safety control in different navigation zones using a spatial sequential DEA model: Yangtze River case.

PubMed

Wu, Bing; Wang, Yang; Zhang, Jinfen; Savan, Emanuel Emil; Yan, Xinping

2015-08-01

This paper aims to analyze the effectiveness of maritime safety control from the perspective of safety level along the Yangtze River with special considerations for navigational environments. The influencing variables of maritime safety are reviewed, including ship condition, maritime regulatory system, human reliability and navigational environment. Because the former three variables are generally assumed to be of the same level of safety, this paper focuses on studying the impact of navigational environments on the level of safety in different waterways. An improved data envelopment analysis (DEA) model is proposed by treating the navigational environment factors as inputs and ship accident data as outputs. Moreover, because the traditional DEA model cannot provide an overall ranking of different decision making units (DMUs), the spatial sequential frontiers and grey relational analysis are incorporated into the DEA model to facilitate a refined assessment. Based on the empirical study results, the proposed model is able to solve the problem of information missing in the prior models and evaluate the level of safety with a better accuracy. The results of the proposed DEA model are further compared with an evidential reasoning (ER) method, which has been widely used for level of safety evaluations. A sensitivity analysis is also conducted to better understand the relationship between the variation of navigational environments and level of safety. The sensitivity analysis shows that the level of safety varies in terms of traffic flow. It indicates that appropriate traffic control measures should be adopted for different waterways to improve their safety. This paper presents a practical method of conducting maritime level of safety assessments under dynamic navigational environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Airport Surface Control Systems Development Analysis Expanded

DOT National Transportation Integrated Search

1990-01-01

A previous MITRE Technical Report, Airport Surface Traffic Control Systems Deployment Analysis, FAA-RD-74-6, presented an analysis of ASTC (Airport Surface Traffic Control) system requirements and developed estimates of the deployment potential of pr...

Human health risk assessment of lead pollution in atmospheric deposition in Baoshan District, Shanghai.

PubMed

Chen, Yuanyuan; Wang, Jun; Shi, Guitao; Sun, Xiaojing; Chen, Zhenlou; Xu, Shiyuan

2011-12-01

The lead (Pb) content in atmospheric deposition was determined at 42 sampling sites in Baoshan District of Shanghai, China. Based on exposure and dose-response assessments, the health risk caused by Pb exposure in atmospheric deposition was investigated. The results indicated that Pb was significantly accumulated in atmospheric deposition. The spatial distribution of Pb was mapped by geostatistical analysis, and the results showed that pollution hotspots were present at traffic and industrial zones. Ingestion was the main route of Pb exposure in both adults and children. For children the risk value was above 1, whereas it was below 1 for the adult group. Therefore, children belong to the high-risk group for Pb exposure from atmospheric deposition in the observed area of Shanghai, China.

Predicting Average Vehicle Speed in Two Lane Highways Considering Weather Condition and Traffic Characteristics

NASA Astrophysics Data System (ADS)

Mirbaha, Babak; Saffarzadeh, Mahmoud; AmirHossein Beheshty, Seyed; Aniran, MirMoosa; Yazdani, Mirbahador; Shirini, Bahram

2017-10-01

Analysis of vehicle speed with different weather condition and traffic characteristics is very effective in traffic planning. Since the weather condition and traffic characteristics vary every day, the prediction of average speed can be useful in traffic management plans. In this study, traffic and weather data for a two-lane highway located in Northwest of Iran were selected for analysis. After merging traffic and weather data, the linear regression model was calibrated for speed prediction using STATA12.1 Statistical and Data Analysis software. Variables like vehicle flow, percentage of heavy vehicles, vehicle flow in opposing lane, percentage of heavy vehicles in opposing lane, rainfall (mm), snowfall and maximum daily wind speed more than 13m/s were found to be significant variables in the model. Results showed that variables of vehicle flow and heavy vehicle percent acquired the positive coefficient that shows, by increasing these variables the average vehicle speed in every weather condition will also increase. Vehicle flow in opposing lane, percentage of heavy vehicle in opposing lane, rainfall amount (mm), snowfall and maximum daily wind speed more than 13m/s acquired the negative coefficient that shows by increasing these variables, the average vehicle speed will decrease.

Traffic noise analysis protocol for new highway construction and reconstruction projects.

DOT National Transportation Integrated Search

1998-10-01

The Traffic Noise Analysis Protocol (hereafter referred to as the Protocol) : contains Caltrans noise policies, which fulfill the highway noise analysis and : abatement/mitigation requirements stemming from the following State and : Federal environme...

Visual Analysis of Air Traffic Data

NASA Technical Reports Server (NTRS)

Albrecht, George Hans; Pang, Alex

2012-01-01

In this paper, we present visual analysis tools to help study the impact of policy changes on air traffic congestion. The tools support visualization of time-varying air traffic density over an area of interest using different time granularity. We use this visual analysis platform to investigate how changing the aircraft separation volume can reduce congestion while maintaining key safety requirements. The same platform can also be used as a decision aid for processing requests for unmanned aerial vehicle operations.

In-depth analysis of drivers' merging behavior and rear-end crash risks in work zone merging areas.

PubMed

Weng, Jinxian; Xue, Shan; Yang, Ying; Yan, Xuedong; Qu, Xiaobo

2015-04-01

This study investigates the drivers' merging behavior and the rear-end crash risk in work zone merging areas during the entire merging implementation period from the time of starting a merging maneuver to that of completing the maneuver. With the merging traffic data from a work zone site in Singapore, a mixed probit model is developed to describe the merging behavior, and two surrogate safety measures including the time to collision (TTC) and deceleration rate to avoid the crash (DRAC) are adopted to compute the rear-end crash risk between the merging vehicle and its neighboring vehicles. Results show that the merging vehicle has a bigger probability of completing a merging maneuver quickly under one of the following situations: (i) the merging vehicle moves relatively fast; (ii) the merging lead vehicle is a heavy vehicle; and (iii) there is a sizable gap in the adjacent through lane. Results indicate that the rear-end crash risk does not monotonically increase as the merging vehicle speed increases. The merging vehicle's rear-end crash risk is also affected by the vehicle type. There is a biggest increment of rear-end crash risk if the merging lead vehicle belongs to a heavy vehicle. Although the reduced remaining distance to work zone could urge the merging vehicle to complete a merging maneuver quickly, it might lead to an increased rear-end crash risk. Interestingly, it is found that the rear-end crash risk could be generally increased over the elapsed time after the merging maneuver being triggered. Copyright © 2015 Elsevier Ltd. All rights reserved.

2006 Oregon traffic crash summary

DOT National Transportation Integrated Search

2007-06-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

2007 Oregon traffic crash summary

DOT National Transportation Integrated Search

2008-07-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

2005 Oregon traffic crash summary

DOT National Transportation Integrated Search

2006-06-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring : on city streets, county roads and state highways. The data supports various local, county and state traffic : safety programs, engineering and ...

Dynamical analysis of Lorenz System on traffic problem in Yogyakarta, Indonesia

NASA Astrophysics Data System (ADS)

Hartono; Saptaningtyas, F. Y.; Krisnawan, K. P.

2018-03-01

The traffic congestion becomes a routine problem which occurs in Yogyakarta. This study was to develop a mathematical model of traffic congestion using Lorenz System. This system was used to analyze the traffic condition in Yogyakarta road. The data was taken from the observation of the road and it had been validated. Routh Hourwith used to analyse the stability of free jamm equlibrium. The dynamic analysis showed that the system was stabil. Numerical solution showed that the bigger value of ratio of the distance relaxsation time to velocity relaxsation time resulting the more time to reach the stabil condition. It showed that more and more time to reach optimal velocity, needed more and more time as well to reach equilibrium. Traffic condition at the time of observation was ideal and there was no transition of traffic jam.

US Traffic Fatalities, 1985–2014, and Their Relationship to Medical Marijuana Laws

PubMed Central

Mauro, Christine M.; Wall, Melanie M.; Kim, June H.; Cerdá, Magdalena; Keyes, Katherine M.; Hasin, Deborah S.; Galea, Sandro; Martins, Silvia S.

2017-01-01

Objectives. To determine the association of medical marijuana laws (MMLs) with traffic fatality rates. Methods. Using data from the 1985–2014 Fatality Analysis Reporting System, we examined the association between MMLs and traffic fatalities in multilevel regression models while controlling for contemporaneous secular trends. We examined this association separately for each state enacting MMLs. We also evaluated the association between marijuana dispensaries and traffic fatalities. Results. On average, MML states had lower traffic fatality rates than non-MML states. Medical marijuana laws were associated with immediate reductions in traffic fatalities in those aged 15 to 24 and 25 to 44 years, and with additional yearly gradual reductions in those aged 25 to 44 years. However, state-specific results showed that only 7 states experienced post-MML reductions. Dispensaries were also associated with traffic fatality reductions in those aged 25 to 44 years. Conclusions. Both MMLs and dispensaries were associated with reductions in traffic fatalities, especially among those aged 25 to 44 years. State-specific analysis showed heterogeneity of the MML–traffic fatalities association, suggesting moderation by other local factors. These findings could influence policy decisions on the enactment or repealing of MMLs and how they are implemented. PMID:27997245

Identifying compromised systems through correlation of suspicious traffic from malware behavioral analysis

NASA Astrophysics Data System (ADS)

Camilo, Ana E. F.; Grégio, André; Santos, Rafael D. C.

2016-05-01

Malware detection may be accomplished through the analysis of their infection behavior. To do so, dynamic analysis systems run malware samples and extract their operating system activities and network traffic. This traffic may represent malware accessing external systems, either to steal sensitive data from victims or to fetch other malicious artifacts (configuration files, additional modules, commands). In this work, we propose the use of visualization as a tool to identify compromised systems based on correlating malware communications in the form of graphs and finding isomorphisms between them. We produced graphs from over 6 thousand distinct network traffic files captured during malware execution and analyzed the existing relationships among malware samples and IP addresses.

Traffic Flow Density Distribution Based on FEM

NASA Astrophysics Data System (ADS)

Ma, Jing; Cui, Jianming

In analysis of normal traffic flow, it usually uses the static or dynamic model to numerical analyze based on fluid mechanics. However, in such handling process, the problem of massive modeling and data handling exist, and the accuracy is not high. Finite Element Method (FEM) is a production which is developed from the combination of a modern mathematics, mathematics and computer technology, and it has been widely applied in various domain such as engineering. Based on existing theory of traffic flow, ITS and the development of FEM, a simulation theory of the FEM that solves the problems existing in traffic flow is put forward. Based on this theory, using the existing Finite Element Analysis (FEA) software, the traffic flow is simulated analyzed with fluid mechanics and the dynamics. Massive data processing problem of manually modeling and numerical analysis is solved, and the authenticity of simulation is enhanced.

Development of a lane change risk index using vehicle trajectory data.

PubMed

Park, Hyunjin; Oh, Cheol; Moon, Jaepil; Kim, Seongho

2018-01-01

Surrogate safety measures (SSMs) have been widely used to evaluate crash potential, which is fundamental for the development of effective safety countermeasures. Unlike existing SSMs, which are mainly focused on the evaluation of longitudinal vehicle maneuvering leading to rear-end crashes, this study proposes a new method for estimating crash risk while a subject vehicle changes lanes, referred to as the lane change risk index (LCRI). A novel feature of the proposed methodology is its incorporation of the amount of exposure time to potential crash and the expected crash severity level by applying a fault tree analysis (FTA) to the evaluation framework. Vehicle interactions between a subject vehicle and adjacent vehicles in the starting lane and the target lane are evaluated in terms of crash potential during lane change. Vehicle trajectory data obtained from a traffic stream, photographed using a drone flown over a freeway segment, is used to investigate the applicability of the proposed methodology. This study compares the characteristics of compulsory and discretionary lane changes observed in a work zone section and a general section of a freeway using the LCRI. It is expected that the outcome of this study will be valuable in evaluating the effectiveness of various traffic operations and control strategies in terms of lane change safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adapting ISA system warnings to enhance user acceptance.

PubMed

Jiménez, Felipe; Liang, Yingzhen; Aparicio, Francisco

2012-09-01

Inappropriate speed is a major cause of traffic accidents. Different measures have been considered to control traffic speed, and intelligent speed adaptation (ISA) systems are one of the alternatives. These systems know the speed limits and try to improve compliance with them. This paper deals with an informative ISA system that provides the driver with an advance warning before reaching a road section with singular characteristics that require a lower safe speed than the current speed. In spite of the extensive tests performed using ISA systems, few works show how warnings can be adapted to the driver. This paper describes a method to adapt warning parameters (safe speed on curves, zone of influence of a singular stretch, deceleration process and reaction time) to normal driving behavior. The method is based on a set of tests with and without the ISA system. This adjustment, as well as the analysis of driver acceptance before and after the adaptation and changes in driver behavior (changes in speed and path) resulting from the tested ISA regarding a driver's normal driving style, is shown in this paper. The main conclusion is that acceptance by drivers increased significantly after redefining the warning parameters, but the effect of speed homogenization was not reduced. Copyright © 2010 Elsevier Ltd. All rights reserved.

A cross-comparison of different techniques for modeling macro-level cyclist crashes.

PubMed

Guo, Yanyong; Osama, Ahmed; Sayed, Tarek

2018-04-01

Despite the recognized benefits of cycling as a sustainable mode of transportation, cyclists are considered vulnerable road users and there are concerns about their safety. Therefore, it is essential to investigate the factors affecting cyclist safety. The goal of this study is to evaluate and compare different approaches of modeling macro-level cyclist safety as well as investigating factors that contribute to cyclist crashes using a comprehensive list of covariates. Data from 134 traffic analysis zones (TAZs) in the City of Vancouver were used to develop macro-level crash models (CM) incorporating variables related to actual traffic exposure, socio-economics, land use, built environment, and bike network. Four types of CMs were developed under a full Bayesian framework: Poisson lognormal model (PLN), random intercepts PLN model (RIPLN), random parameters PLN model (RPPLN), and spatial PLN model (SPLN). The SPLN model had the best goodness of fit, and the results highlighted the significant effects of spatial correlation. The models showed that the cyclist crashes were positively associated with bike and vehicle exposure measures, households, commercial area density, and signal density. On the other hand, negative associations were found between cyclist crashes and some bike network indicators such as average edge length, average zonal slope, and off-street bike links. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stability analysis of feedforward anticipation optimal flux difference in traffic lattice hydrodynamic theory

NASA Astrophysics Data System (ADS)

Sun, Di-Hua; Zhang, Geng; Zhao, Min; Cheng, Sen-Lin; Cao, Jian-Dong

2018-03-01

Recently, the influence of driver's individual behaviors on traffic stability is research hotspot with the fasting developing transportation cyber-physical systems. In this paper, a new traffic lattice hydrodynamic model is proposed with consideration of driver's feedforward anticipation optimal flux difference. The neutral stability condition of the new model is obtained through linear stability analysis theory. The results show that the stable region will be enlarged on the phase diagram when the feedforward anticipation optimal flux difference effect is taken into account. In order to depict traffic jamming transition properties theoretically, the mKdV equation near the critical point is derived via nonlinear reductive perturbation method. The propagation behavior of traffic density waves can be described by the kink-antikink solution of the mKdV equation. Numerical simulations are conducted to verify the analytical results and all the results confirms that traffic stability can be enhanced significantly by considering the feedforward anticipation optimal flux difference in traffic lattice hydrodynamic theory.

[Trends in traffic accident mortality in Spain, 1962-1994].

PubMed

Redondo Calderón, J; Luna Del Castillo, J D; Jiménez Moleón, J J; Lardelli Claret, P; Gálvez Vargas, R

2000-01-01

To assess the evolution of the traffic accident mortality rate in Spain from 1962 to 1994, and the role played by its four theoretical components: motorization index (vehicles/population), accidentability index (accidents/vehicles), harmfulness index (victims/accidents) and fatality index (deaths/victims). Data from the National Population Census and the Bulletin of the Dirección General de Tráfico were collected to estimate the above mentioned indicators for all accidents and accidents in road and urban zones. Simple and multiple partial correlation coefficients among variables were calculated. Poisson regression models were also obtained. An increasing trend during the whole period was observed for the national traffic accident mortality rate, especially from 1982 to 1989 in the younger age groups, followed by a decrease since 1990. The aforementioned four components were significatively associated with the mortality rate. The strength of this association was especially high for the motorization index and for the harmfulness index when all accidents and road accidents were considered. For urban accidents, the fatality index rate is the component most strongly associated with mortality rate. The role played by the accidentability index in the magnitude of the mortality rate seems less important. The growing exposure rate to traffic accidents observed in Spain (measured by the motorization index) is not directly influenced by public heath strategies. Therefore, it seems advisable to emphasize the development of measures focused to control the other three components of traffic accident mortality rate, especially those related with harmfulness and fatality.

Game-theoretic analysis of dynamic traffic equilibria.

DOT National Transportation Integrated Search

2014-03-01

Dynamic traffic assignment has grown steadily in popularity and use since its inception. It has become an : important and permanent tool in transportation agencies across the country. However, the exact nature of : dynamic traffic equilibrium, includ...

2003 Oregon traffic crash summary

DOT National Transportation Integrated Search

2004-10-01

The Crash Analysis and Reporting Unit compiles data for reported motor vehicle traffic crashes occurring on city streets, county roads and state highways. The data supports various local, county and state traffic safety programs, engineering and plan...

Exploratory statistical and geographical freight traffic data analysis

DOT National Transportation Integrated Search

2000-08-01

Data from freight traffic roadside surveys in Mexican highways are analyzed in order to find consistent patterns or systematic relationships between variables characterizing this traffic. Patterns traced are validated by contrasting against new data ...

Chinese traffic fatalities and injuries in police reports, hospital records, and in-depth records from one city.

PubMed

Qiu, Jun; Zhou, Jihong; Zhang, Liang; Yao, Yuan; Yuan, Danfeng; Shi, Jianguo; Gao, Zhiming; Zhou, Lin; Wang, Zhengguo; Evans, Leonard

2015-01-01

Claims of sharp reductions in Chinese traffic casualties after 2002 based on police-reported data have been questioned in the literature. The objective of this study is to determine whether a decline in casualties occurred and to better understand the police data. The first of 2 unrelated studies analyzed data from 210 military hospitals throughout China providing records for inpatients injured in traffic accidents (2001-2007). The second compared in-depth crash records (2000-2006) from one city to officially released data. Hospital data showed that casualties increased from 2002 to 2007. The city investigation showed consistently far more fatalities and injuries in the in-depth data than officially released. For example, in-depth data showed 1,720 fatalities. Only 557 of these were reported officially (data loss = 68%). Disaggregating into 3 regions showed a data loss of 41% in urban areas, 63% in rural areas, and 90% in rural-urban fringe zones. For injuries, data losses were even greater. Traffic fatalities and injuries did not decrease from 2002 to 2006. The in-depth city data contained 3 times as many fatalities and 5 times as many injuries as reported by police. Reasons why this occurred and suggestions to improve data collection and reduce casualties are given.

Assessment of traffic noise levels in urban areas using different soft computing techniques.

PubMed

Tomić, J; Bogojević, N; Pljakić, M; Šumarac-Pavlović, D

2016-10-01

Available traffic noise prediction models are usually based on regression analysis of experimental data, and this paper presents the application of soft computing techniques in traffic noise prediction. Two mathematical models are proposed and their predictions are compared to data collected by traffic noise monitoring in urban areas, as well as to predictions of commonly used traffic noise models. The results show that application of evolutionary algorithms and neural networks may improve process of development, as well as accuracy of traffic noise prediction.

Potential safety benefits of intelligent cruise control systems.

PubMed

Chira-Chavala, T; Yoo, S M

1994-04-01

Potential safety impact of a hypothetical intelligent cruise control system (ICCS) is evaluated in terms of changes in traffic accidents and some traffic operation characteristics affecting safety. The analysis of changes in traffic accidents is accomplished by in-depth examinations of police accident reports for four major counties in California. The evaluation of changes in traffic operation characteristics affecting safety is accomplished by vehicle simulation. The accident analysis reveals that the use of the hypothetical ICCS could potentially reduce traffic accidents by up to 7.5%. Preliminary vehicle simulation results based on a 10-vehicle convoy indicate that the use of the hypothetical ICCS could reduce frequencies of hard acceleration and deceleration, enhance speed harmonization among vehicles, and reduce incidence of "less-safe" headway.

Seven Experiment Designs Addressing Problems of Safety and Capacity on Two-Lane Rural Highways : Volume 8. Experimental Design and Evaluate Remedial Aids for Intersections with Inadequate Sight Distance

DOT National Transportation Integrated Search

2007-01-01

Americans lose 3.7 billion hours and 2.3 billion gallons of fuel every year sitting in traffic jams, and nearly 24 percent of non-recurring freeway delay, or about 482 million hours, is attributed to work zones. To combat the country's growing transp...

Airborne Remote Sensing of Trafficability in the Coastal Zone

DTIC Science & Technology

2009-01-01

validation instruments: Analytical Spectral Devices (ASD) full-range spectrometer; light weight deflectometer ( LWD ), which measures dynamic deflection...liquid water absorption features. The corresponding bearing strength measured by the LWD was high at the shoreline site and low at the backdune site...REVIEW REMOTE SENSING FIGURE 7 Correlation of in situ grain size, moisture, and bearing strength measurements. Scatterplot of percent moisture vs LWD

14 CFR 99.45 - Alaska ADIZ.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Alaska ADIZ. 99.45 Section 99.45 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC... Zones § 99.45 Alaska ADIZ. The area is bounded by a line from 54°00′N; 136°00′W; 56°57′N; 144°00′W; 57...

Analysis and Classification of Traffic in Wireless Sensor Network

DTIC Science & Technology

2007-03-01

34 1. Hurst Parameter ................................................................................35 2. Self-Similarity...traffic is self-similar, buffer size can be better designed from the forecasted traffic workload. 1. Hurst Parameter To determine the extent of self...similarity in WSN traffic, the Hurst parameter, H, is used. H also calculates the length of the long range dependence of a stochastic process. If H

Overview of surface measurements and spatial characterization of submicrometer particulate matter during the DISCOVER-AQ 2013 campaign in Houston, TX.

PubMed

Leong, Y J; Sanchez, N P; Wallace, H W; Karakurt Cevik, B; Hernandez, C S; Han, Y; Flynn, J H; Massoli, P; Floerchinger, C; Fortner, E C; Herndon, S; Bean, J K; Hildebrandt Ruiz, L; Jeon, W; Choi, Y; Lefer, B; Griffin, R J

2017-08-01

The sources of submicrometer particulate matter (PM 1 ) remain poorly characterized in the industrialized city of Houston, TX. A mobile sampling approach was used to characterize PM 1 composition and concentration across Houston based on high-time-resolution measurements of nonrefractory PM 1 and trace gases during the DISCOVER-AQ Texas 2013 campaign. Two pollution zones with marked differences in PM 1 levels, character, and dynamics were established based on cluster analysis of organic aerosol mass loadings sampled at 16 sites. The highest PM 1 mass concentrations (average 11.6 ± 5.7 µg/m 3 ) were observed to the northwest of Houston (zone 1), dominated by secondary organic aerosol (SOA) mass likely driven by nighttime biogenic organonitrate formation. Zone 2, an industrial/urban area south/east of Houston, exhibited lower concentrations of PM 1 (average 4.4 ± 3.3 µg/m 3 ), significant organic aerosol (OA) aging, and evidence of primary sulfate emissions. Diurnal patterns and backward-trajectory analyses enable the classification of airmass clusters characterized by distinct PM sources: biogenic SOA, photochemical aged SOA, and primary sulfate emissions from the Houston Ship Channel. Principal component analysis (PCA) indicates that secondary biogenic organonitrates primarily related with monoterpenes are predominant in zone 1 (accounting for 34% of the variability in the data set). The relevance of photochemical processes and industrial and traffic emission sources in zone 2 also is highlighted by PCA, which identifies three factors related with these processes/sources (~50% of the aerosol/trace gas concentration variability). PCA reveals a relatively minor contribution of isoprene to SOA formation in zone 1 and the absence of isoprene-derived aerosol in zone 2. The relevance of industrial amine emissions and the likely contribution of chloride-displaced sea salt aerosol to the observed variability in pollution levels in zone 2 also are captured by PCA. This article describes an urban-scale mobile study to characterize spatial variations in submicrometer particulate matter (PM 1 ) in greater Houston. The data set indicates substantial spatial variations in PM 1 sources/chemistry and elucidates the importance of photochemistry and nighttime oxidant chemistry in producing secondary PM 1 . These results emphasize the potential benefits of effective control strategies throughout the region, not only to reduce primary emissions of PM 1 from automobiles and industry but also to reduce the emissions of important secondary PM 1 precursors, including sulfur oxides, nitrogen oxides, ammonia, and volatile organic compounds. Such efforts also could aid in efforts to reduce mixing ratios of ozone.

Right-Turn Traffic Volume Adjustments in Traffic Signal Warrant Analysis

DOT National Transportation Integrated Search

2015-01-01

To accomplish this research, a comprehensive literature review of existing guidelines and findings based on national and local studies was conducted. Ultimately, guidelines for consistent application for adjusting right-turn traffic volumes were deve...

Demonstration of the application of traffic management center decision support tools.

DOT National Transportation Integrated Search

2013-03-01

Decision support tools were developed in previous Florida Department of Transportation (FDOT) : research projects to allow for better analysis and visualization of historical traffic and incident : data, in support of incident management and traffic ...

2009 Oregon traffic crash summary

DOT National Transportation Integrated Search

2010-09-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

Buffalo Air Traffic Control Tower Operations Analysis.

DOT National Transportation Integrated Search

1981-09-01

This report provides a description of the non-surveillance aspects of the FAA air traffic control facility operation at Greater Buffalo International Airport from the air traffic controller's point of view. It includes photographs of all controller c...

2008 Oregon traffic crash summary

DOT National Transportation Integrated Search

2009-09-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

2010 Oregon traffic crash summary

DOT National Transportation Integrated Search

2011-08-01

The Crash Analysis and Reporting Unit compiles data and publishes statistics for reported motor vehicle : traffic crashes per ORS 802.050(2) and 802.220(6). The data supports various local, county and state : traffic safety programs, engineering and ...

Exploiting geo-distributed clouds for a e-health monitoring system with minimum service delay and privacy preservation.

PubMed

Shen, Qinghua; Liang, Xiaohui; Shen, Xuemin; Lin, Xiaodong; Luo, Henry Y

2014-03-01

In this paper, we propose an e-health monitoring system with minimum service delay and privacy preservation by exploiting geo-distributed clouds. In the system, the resource allocation scheme enables the distributed cloud servers to cooperatively assign the servers to the requested users under the load balance condition. Thus, the service delay for users is minimized. In addition, a traffic-shaping algorithm is proposed. The traffic-shaping algorithm converts the user health data traffic to the nonhealth data traffic such that the capability of traffic analysis attacks is largely reduced. Through the numerical analysis, we show the efficiency of the proposed traffic-shaping algorithm in terms of service delay and privacy preservation. Furthermore, through the simulations, we demonstrate that the proposed resource allocation scheme significantly reduces the service delay compared to two other alternatives using jointly the short queue and distributed control law.

Twenty-four hour peaking relationship to level of service and other measures of effectiveness.

DOT National Transportation Integrated Search

2015-06-01

Transportation planners and traffic engineers are increasingly interested in traffic analysis tools that analyze : demand profiles and performance that go beyond analysis of the traditional peak hours and extend the analysis to : other hours of the d...