Development of a Procedure for Estimating Expected Safety Effects of a Contemplated Traffic Signal Installation

2003 ◽  
Vol 1840 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Bhagwant Persaud ◽  
Hugh McGee ◽  
Craig Lyon ◽  
Dominique Lord
Keyword(s):  
Economic Evaluation ◽  
Traffic Control ◽  
Empirical Bayes ◽  
Prediction Models ◽  
State Of The Art ◽  
Traffic Signal ◽  
Accident Prediction ◽  
Engineering Study ◽  
Control Devices ◽  
Safety Estimation

The Manual on Uniform Traffic Control Devices contains warrants for traffic signal installation but cautions that satisfying a warrant does not in itself justify the decision to install a signal and that one should not be installed unless an engineering study indicates that this will improve the overall safety or operation of the intersection. The development of an easily implementable procedure, which is intended to be part of an engineering study, for estimation of the expected safety effects of a contemplated signal installation is reported. These effects can then be considered in conjunction with other impacts in a conventional economic evaluation. The development of the procedure by use of a multijurisdiction database is described, and a detailed illustration is presented. Use is made of the empirical Bayes methodology that of late has been recognized as the state of the art in safety estimation and of the most recent advances in that methodology. Substantial focus is placed on the application of that methodology and on the development of the accident prediction models required to support that application. The development of the procedure is part of an NCHRP project (NCHRP 17-16) that aims to improve the safety warrant for signal installation and, more generally, to determine how safety is considered in the decision to install or not install a signal.

scholarly journals Identifying Expressway Accident Black Spots Based on the Secondary Division of Road Units

2021 ◽  
Vol 33 (5) ◽  
pp. 731-743
Author(s):  
Guohua Liang ◽  
Xujiao Sun ◽  
Yidan Zhang ◽  
Mingli Chen ◽  
Wanting Zhang
Keyword(s):  
Empirical Bayes ◽  
Traffic Accidents ◽  
Prediction Models ◽  
Control Method ◽  
Bayes Method ◽  
Accident Prediction ◽  
Related Data ◽  
Black Spots ◽  
Empirical Bayes Method ◽  
Safety Estimation

For the purpose of reducing the harm of expressway traffic accidents and improving the accuracy of traffic accident black spots identification, this paper proposes a method for black spots identification of expressway accidents based on road unit secondary division and empirical Bayes method. Based on the modelling ideas of expressway accident prediction models in HSM (Highway Safety Manual), an expressway accident prediction model is established as a prior distribution and combined with empirical Bayes method safety estimation to obtain a Bayes posterior estimate. The posterior estimated value is substituted into the quality control method to obtain the black spots identification threshold. Finally, combining the Xi'an-Baoji expressway related data and using the method proposed in this paper, a case study of Xibao Expressway is carried out, and sections 9, 19, and 25 of Xibao Expressway are identified as black spots. The results show that the method of secondary segmentation based on dynamic clustering can objectively describe the concentration and dispersion of accident spots on the expressway, and the proposed black point recognition method based on empirical Bayes method can accurately identify accident black spots. The research results of this paper can provide a basis for decision-making of expressway management departments, take targeted safety improvement measures.

scholarly journals Evaluation of Design Standards of Four-Hour Volume Traffic Signal Warrant

2012 ◽  
Vol 49 (3) ◽  
Author(s):  
Xuesong Zhu ◽  
Albert Gan ◽  
David Shen
Keyword(s):  
Traffic Control ◽  
Traffic Signal ◽  
Microscopic Simulation ◽  
Design Standards ◽  
Control Delay ◽  
Critical Design ◽  
Design Values ◽  
Average Control ◽  
Street Traffic ◽  
Control Devices

Traffic signal warrants set the minimum conditions under which a traffic signal installation may be appropriate. The four-hour volume signal warrant in the current Manual on Uniform Traffic Control Devices (MUTCD) (FHWA 2009) is applied based on a set of critical vehicular volumes for different lane combinations of major and minor streets. This paper describes an effort to apply microscopic simulation to evaluate the critical volumes used in the four-hour warrant. The results show significant differences in average control delay for minor street traffic under different volume combinations, lane configurations, turning volume percentages, heavy vehicle percentages, and the number of major street lanes (four versus six lanes), most of which are not currently considered in the four-hour warrant. This finding provides some evidence of the need to possibly revise the critical design values of the current four-hour volume warrant.

Guidelines for Identification of Hazardous Highway Curves

2000 ◽  
Vol 1717 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Bhagwant Persaud ◽  
Richard A. Retting ◽  
Craig Lyon
Keyword(s):  
Traffic Control ◽  
Empirical Bayes ◽  
Low Cost ◽  
Cost Effective ◽  
Warning Signs ◽  
Potential Treatment ◽  
Control Devices ◽  
Traffic Control Devices ◽  
The U.S

Curve-warning treatment can be extremely cost-effective because of the low cost of treatments, such as curve warning signs or markings, and the potentially large number of target crashes. However, measures are needed to identify and prioritize treatment of potentially hazardous rural curves. An empirical Bayes-based procedure is presented for prioritizing potential treatment sites on the basis of crashes that may be classified as occurring because of the presence of curves. The attractiveness of the procedure is enhanced by the fact that the data and calculations are also a part of the evaluation of treatment that may be applied to sites identified. Alternative levels of the procedure can be selected, depending on the data available. Ontario data were used to calibrate supporting models. It is hoped that experience gained from using the guidelines can lead to the development of procedures that can be incorporated into the U.S. Department of Transportation’s Manual on Uniform Traffic Control Devices.

scholarly journals Development of accident prediction models for pedestrian crossings

2018 ◽  
Vol 231 ◽  
pp. 03002
Author(s):  
Piotr Olszewski ◽  
Beata Osińska ◽  
Piotr Szagała ◽  
Paweł Włodarek
Keyword(s):  
Traffic Safety ◽  
Empirical Bayes ◽  
Negative Binomial ◽  
Prediction Models ◽  
Heavy Vehicles ◽  
Factors Affecting ◽  
Accident Prediction ◽  
Accident Data ◽  
Pedestrian Accidents ◽  
Mixed Land Use

In large Polish cities like Warsaw, pedestrians constitute almost 60% of road fatalities. Although traffic safety situation in general is improving, the numbers of pedestrians hit when crossing a road have not significantly decreased over the last six years. A negative binomial model was estimated for predicting accidents at unsignalised pedestrian crossings based on accident data from 52 crossings in Warsaw. A total of 58 pedestrian accidents were recorded at these crossings during the last seven years. The model shows that the number of accidents is less-than-proportional to both pedestrian and motorised traffic daily volumes. Other risk factors affecting pedestrian safety are: higher proportion of heavy vehicles and location in a mixed land use area. The model can be used with the Empirical Bayes method for an unbiased identification of high risk locations.

scholarly journals Accident and hazard prediction models for highway–rail grade crossings: a state-of-the-practice review for the USA

2020 ◽  
Vol 28 (3) ◽  
pp. 251-274
Author(s):  
Olumide F. Abioye ◽  
Maxim A. Dulebenets ◽  
Junayed Pasha ◽  
Masoud Kavoosi ◽  
Ren Moses ◽  
...  
Keyword(s):  
Traffic Control ◽  
Prediction Models ◽  
Transportation Network ◽  
Data Availability ◽  
Severe Injuries ◽  
Accident Prediction ◽  
Implementation Challenges ◽  
The Usa ◽  
Practice Review ◽  
Grade Crossings

Abstract Highway–rail grade crossings (HRGCs) are one of the most dangerous segments of the transportation network. Every year numerous accidents are recorded at HRGCs between highway users and trains, between highway users and traffic control devices, and solely between highway users. These accidents cause fatalities, severe injuries, property damage, and release of hazardous materials. Researchers and state Departments of Transportation (DOTs) have addressed safety concerns at HRGCs in the USA by investigating the factors that may cause accidents at HRGCs and developed certain accident and hazard prediction models to forecast the occurrence of accidents and crossing vulnerability. The accident and hazard prediction models are used to identify the most hazardous HRGCs that require safety improvements. This study provides an extensive review of the state-of-the-practice to identify the existing accident and hazard prediction formulae that have been used over the years by different state DOTs. Furthermore, this study analyzes the common factors that have been considered in the existing accident and hazard prediction formulae. The reported performance and implementation challenges of the identified accident and hazard prediction formulae are discussed in this study as well. Based on the review results, the US DOT Accident Prediction Formula was found to be the most commonly used formula due to its accuracy in predicting the number of accidents at HRGCs. However, certain states still prefer customized models due to some practical considerations. Data availability and data accuracy were identified as some of the key model implementation challenges in many states across the country.

Accident prediction models with random corridor parameters

2009 ◽  
Vol 41 (5) ◽  
pp. 1118-1123 ◽  
Author(s):  
Karim El-Basyouny ◽  
Tarek Sayed
Keyword(s):  
Prediction Models ◽  
Accident Prediction

New Intersection Crash Prediction Models for the Second Edition of the Highway Safety Manual

2021 ◽  
pp. 036119812110398
Author(s):  
Darren J. Torbic ◽  
Daniel Cook ◽  
Joseph Grotheer ◽  
Richard Porter ◽  
Jeffrey Gooch ◽  
...  
Keyword(s):  
Traffic Control ◽  
Prediction Models ◽  
Highway Safety ◽  
Crash Severity ◽  
Crash Prediction ◽  
Part C ◽  
Highway Safety Manual ◽  
Rural And Urban ◽  
Diamond Interchanges ◽  
Crash Prediction Models

The objective of this research was to develop new intersection crash prediction models for consideration in the second edition of the Highway Safety Manual (HSM), consistent with existing methods in HSM Part C and comprehensive in their ability to address a wide range of intersection configurations and traffic control types in rural and urban areas. The focus of the research was on developing safety performance functions (SPFs) for intersection configurations and traffic control types not currently addressed in HSM Part C. SPFs were developed for the following general intersection configurations and traffic control types: rural and urban all-way stop-controlled intersections; rural three-leg intersections with signal control; intersections on high-speed urban and suburban arterials (i.e., arterials with speed limits greater than or equal to 50 mph); urban five-leg intersections with signal control; three-leg intersections where the through movements make turning maneuvers at the intersections; crossroad ramp terminals at single-point diamond interchanges; and crossroad ramp terminals at tight diamond interchanges. Development of severity distribution functions (SDFs) for use in combination with SPFs to estimate crash severity as a function of geometric design elements and traffic control features was explored; but owing to challenges and inconsistencies in developing and interpreting the SDFs, it was recommended for the second edition of the HSM that crash severity for the new intersection configurations and traffic control types be addressed in a manner consistent with existing methods in Chapters 10, 11, and 12 of the first edition, without use of SDFs.

Use of Big Data to Evaluate and Improve Performance of Traffic Signal Systems in Resource-Constrained Countries

2017 ◽  
Vol 2620 (1) ◽  
pp. 20-30 ◽  
Author(s):  
Yang Carl Lu ◽  
Holly Krambeck ◽  
Liang Tang
Keyword(s):  
Traffic Control ◽  
Time Of Day ◽  
Traffic Signal ◽  
Signal Timing ◽  
Gps Data ◽  
Resource Constrained ◽  
Physical Sensors ◽  
Constrained Environments ◽  
Traffic Signal Timing ◽  
High Level

Deployment of an adaptive area traffic control system is expensive; physical sensors require installation, calibration, and regular maintenance. Because of the high level of technical and financial resources required, area traffic control systems found in developing countries often are minimally functioning. In Cebu City, Philippines, for example, the Sydney Coordinated Adaptive Traffic System was installed before 2000, and fewer than 35% of detectors were still functioning as of January 2015. To address this challenge, a study was designed to determine whether taxi company GPS data are sufficient to evaluate and improve traffic signal timing plans in resource-constrained environments. If this work is successful, the number of physical sensors required to support those systems may be reduced and thereby substantially lower the costs of installation and maintenance. Taxi GPS data provided by a regional taxi-hailing app were used to design and implement methodologies for evaluating the performance of traffic signal timing plans and for deriving updated fixed-dynamic plans, which are fixed plans (with periods based on observable congestion patterns rather than only time of day) iterated regularly until optimization is reached. To date, three rounds of iterations have been conducted to ensure the stability of the proposed signal timings. Results of exploratory analysis indicate that the algorithm is capable of generating reasonable green time splits, but cycle length adjustment must be considered in the future.

Concept Design of Mining System of Seafloor Hydrothermal Deposit

2010 ◽  
Author(s):  
Shinichi Takagawa
Keyword(s):  
Economic Evaluation ◽  
Deep Sea ◽  
Hydrothermal Vents ◽  
Environmental Effect ◽  
State Of The Art ◽  
Concept Design ◽  
Hydrothermal Deposit ◽  
Mining System ◽  
Positive Balance ◽  
Rough Sea

Japan Deep Sea Technology Association had carried out concept design of the mining system for seafloor hydro-thermal deposit from 2008 through 2009. Through this concept design, the economic evaluation of the system with parameter of annual production of the ore was discussed, and it was clarified that more than 500 thousand tons annually would enable us to get positive balance. The environmental effect by mining was also discussed and was concluded that the active hydrothermal vents are not the targets of mining, instead, the dead vents are the targets. Then, the technological feasibility of each subsystem was discussed which constitutes the mining system, from the digger to the surface transporter. Finally, it was concluded that the mining system for hydrothermal deposits is feasible using the state-of-the-art technology even in rough sea around Japan.

scholarly journals Investigating the Applicability of Upstream Detection Strategy at Pedestrian Signalised Crossings

2017 ◽  
Vol 29 (5) ◽  
pp. 503-510 ◽  
Author(s):  
Sitti A Hassan ◽  
Nick B Hounsell ◽  
Birendra P Shrestha
Keyword(s):  
Traffic Control ◽  
Traffic Signal ◽  
Signal Control ◽  
Traffic Signal Control ◽  
Traffic Flows ◽  
Detection Strategy ◽  
Vehicle Delay ◽  
Simulation Results ◽  
The Uk ◽  
User Friendly

In the UK, the Puffin crossing has provision to extend pedestrian green time for those who take longer to cross. However, even at such a pedestrian friendly facility, the traffic signal control is usually designed to minimise vehicle delay while providing the crossing facility. This situation is rather contrary to the current policies to encourage walking. It is this inequity that has prompted the need to re-examine the traffic control of signalised crossings to provide more benefit to both pedestrians and vehicles. In this context, this paper explores the possibility of implementing an Upstream Detection strategy at a Puffin crossing to provide a user friendly crossing. The study has been carried out by simulating a mid-block Puffin crossing for various detector distances and a number of combinations of pedestrian and traffic flows. This paper presents the simulation results and recommends the situations at which Upstream Detection would be suitable.

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