Dilemma Zone Protection on High-speed Arterials

Dilemma Zone Protection on High-speed Arterials PDF Author: Bhaven Naik
Publisher:
ISBN:
Category : Automobile drivers
Languages : en
Pages : 0

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Book Description
"Driver behavior within the dilemma zone can be a major safety concern at high-speed signalized intersections, especially for heavy trucks. The Nebraska Department of ROADS (NDOR) has developed an implemented an Actuated Advance Warning (AAW) dilemma zone protection system. The AAW system has been documented as being effective at improving traffic safety at isolated signalized intersections. However, the system is yet to be used at signalized intersections operating in the coordinated mode. This study tested the feasibility of deploying the system on arterials where the signals are closely spaced and operate in a coordinated mode. A microsimulation approach -- integration of traffic microsimulation and surrogate safety performance measures -- was developed to assess the potential benefits (safety and operation) in-lieu of observed traffic and crash data. The analysis of conflicts indicated that, on average, there were 30%, 7%, and 30% reductions in the number of rear-end, lane change, and crossing conflicts respectively when the AAW system was used. In terms of the relative productivity of the system, the number of vehicles that were processed during a specified analysis period revealed that there were generally more vehicles processed when the AAW system was not in place. Also, the overall link travel times were slightly higher when the system was in place" (page viii).

Dilemma Zone Protection on High-speed Arterials

Dilemma Zone Protection on High-speed Arterials PDF Author: Bhaven Naik
Publisher:
ISBN:
Category : Automobile drivers
Languages : en
Pages : 0

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Book Description
"Driver behavior within the dilemma zone can be a major safety concern at high-speed signalized intersections, especially for heavy trucks. The Nebraska Department of ROADS (NDOR) has developed an implemented an Actuated Advance Warning (AAW) dilemma zone protection system. The AAW system has been documented as being effective at improving traffic safety at isolated signalized intersections. However, the system is yet to be used at signalized intersections operating in the coordinated mode. This study tested the feasibility of deploying the system on arterials where the signals are closely spaced and operate in a coordinated mode. A microsimulation approach -- integration of traffic microsimulation and surrogate safety performance measures -- was developed to assess the potential benefits (safety and operation) in-lieu of observed traffic and crash data. The analysis of conflicts indicated that, on average, there were 30%, 7%, and 30% reductions in the number of rear-end, lane change, and crossing conflicts respectively when the AAW system was used. In terms of the relative productivity of the system, the number of vehicles that were processed during a specified analysis period revealed that there were generally more vehicles processed when the AAW system was not in place. Also, the overall link travel times were slightly higher when the system was in place" (page viii).

Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections

Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections PDF Author: Prahlad D. Pant
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 60

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Book Description
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 generally no more than 2 seconds. If we scan all vehicles on a link just a few seconds before the beginning of a yellow interval, we may be able to extend or cut back the green interval so that the vehicles can avoid the dilemma zone. For each vehicle approaching an intersection on the link that is about to turn yellow, there is a time interval such that (a) the vehicle will be in the dilemma zone without green extension (or cutback) or (b) it will be in the dilemma zone when there are T seconds of extension (or cutback). So the task is to find the smallest nonnegative integer T that is not in any of these time intervals and extend (or cut back) the current interval by T seconds. This T can always be found and assuming there are no other restrictions, dilemma zones can be avoided and the extension (or cutback) is done at most once for each green interval. The simulation study, performed by modifying the source codes of NETSIM, showed that the signal timing generated by a bandwidth maximization program (PASSER-II) resulted in a lower number of vehicles in the dilemma zone than that generated by a delay minimization program (TRANSYT-7F). Additionally, the signal timing generated by the combination of the two programs, that is, by minimizing delay within the constraint of bandwidth maximization, resulted in an even lower number of vehicles in the dilemma zone than those generated by each program alone. The technique developed in this study can be implemented if the speeds and positions of all vehicles on the roadway can be recorded at small time intervals (e.g., 1 sec). Recommendations are made for implementing and testing the developed technique.

International Encyclopedia of Transportation

International Encyclopedia of Transportation PDF Author:
Publisher: Elsevier
ISBN: 0081026722
Category : Law
Languages : en
Pages : 4418

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Book Description
In an increasingly globalised world, despite reductions in costs and time, transportation has become even more important as a facilitator of economic and human interaction; this is reflected in technical advances in transportation systems, increasing interest in how transportation interacts with society and the need to provide novel approaches to understanding its impacts. This has become particularly acute with the impact that Covid-19 has had on transportation across the world, at local, national and international levels. Encyclopedia of Transportation, Seven Volume Set - containing almost 600 articles - brings a cross-cutting and integrated approach to all aspects of transportation from a variety of interdisciplinary fields including engineering, operations research, economics, geography and sociology in order to understand the changes taking place. Emphasising the interaction between these different aspects of research, it offers new solutions to modern-day problems related to transportation. Each of its nine sections is based around familiar themes, but brings together the views of experts from different disciplinary perspectives. Each section is edited by a subject expert who has commissioned articles from a range of authors representing different disciplines, different parts of the world and different social perspectives. The nine sections are structured around the following themes: Transport Modes; Freight Transport and Logistics; Transport Safety and Security; Transport Economics; Traffic Management; Transport Modelling and Data Management; Transport Policy and Planning; Transport Psychology; Sustainability and Health Issues in Transportation. Some articles provide a technical introduction to a topic whilst others provide a bridge between topics or a more future-oriented view of new research areas or challenges. The end result is a reference work that offers researchers and practitioners new approaches, new ways of thinking and novel solutions to problems. All-encompassing and expertly authored, this outstanding reference work will be essential reading for all students and researchers interested in transportation and its global impact in what is a very uncertain world. Provides a forward looking and integrated approach to transportation Updated with future technological impacts, such as self-driving vehicles, cyber-physical systems and big data analytics Includes comprehensive coverage Presents a worldwide approach, including sets of comparative studies and applications

Field Testing and Implementation of Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections

Field Testing and Implementation of Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections PDF Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 96

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Book Description
Historically, high speed signalized intersections have reported many crashes and have always posed a challenge to traffic engineers for enhancing safety at these intersections. The area close to the intersection, called the dilemma zone, poses a high accident potential for the driver in stopping safely during the yellow interval or in proceeding through the intersection before the beginning of red. The driver is in a potentially hazardous situation whereby, if he tries to cross the intersection at the onset of red interval, he may end up in an angle accident with the cross street traffic or if he accelerates through yellow, he may end up in a rear-end collision. The uncertain situation in a dilemma zone can potentially lead to rear-end or right angle collisions.

Placement of Detection Loops on High Speed Approaches to Traffic Signals

Placement of Detection Loops on High Speed Approaches to Traffic Signals PDF Author:
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 136

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Book Description
This report contains the results of the NC Department of Transportation research project Placement of Detection Loops on High Speed Approaches to Traffic Signals (HWY 2007-13). The goal of this project was to determine the best places to locate detectors on the approaches to high-speed signalized intersections and the best signal control strategy to employ in conjunction with those sensor placement ideas to minimize dilemma zone occurrences.

The Efficient Control of an Isolated Vehicle-actuated Controlled Intersection

The Efficient Control of an Isolated Vehicle-actuated Controlled Intersection PDF Author: Pieter Kruger
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 80

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Book Description


Platoon Identification and Accomodation System for Isolated Traffic Signals on Arterials

Platoon Identification and Accomodation System for Isolated Traffic Signals on Arterials PDF Author: Nadeem A. Chaudhary
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 78

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Book Description


Human Factors Guidelines for Road Systems

Human Factors Guidelines for Road Systems PDF Author: John L. Campbell
Publisher: Transportation Research Board
ISBN: 0309258162
Category : Technology & Engineering
Languages : en
Pages : 319

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Book Description
"This report completes and updates the first edition of NCHRP Report 600: Human Factors Guidelines for Road Systems (HFG), which was published previously in three collections. The HFG contains guidelines that provide human factors principles and findings for consideration by, and is a resource document for, highway designers, traffic engineers, and other safety practitioners."--Foreword.

Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances

Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances PDF Author: Jarvis Dale Michie
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 1146

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Book Description


Enhancements to the Advance Warning of End of Green System (AWEGS)

Enhancements to the Advance Warning of End of Green System (AWEGS) PDF Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 148

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Book Description
The objective of this project was to make improvements to the Advance Warning of End of Green System (AWEGS). These improvements have enhanced the operation of AWEGS as well as have made the implementation of AWEGS much simpler. The enhancements include reducing false actuations, accounting for detector failures, detecting and treating queues, improving the visibility of the AWEGS sign, and making numerous modifications to the AWEGS interface.