Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 96
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.
Field Testing and Implementation of Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections
Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 96
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.
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 96
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.
Dilemma Zone Protection and Signal Coordination at Closely-spaced High-speed Intersections
Author: Prahlad D. Pant
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 60
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.
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 60
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.
Human Factors Guidelines for Road Systems
Author: John L. Campbell
Publisher: Transportation Research Board
ISBN: 0309117518
Category : Roads
Languages : en
Pages : 38
Book Description
NCHRP report 600 explores human factors principles and findings for consideration by highway designers and traffic engineers. The report is designed to help the nonexpert in human factors to consider more effectively the roadway user's capabilities and limitations in the design and operation of highway facilities.
Publisher: Transportation Research Board
ISBN: 0309117518
Category : Roads
Languages : en
Pages : 38
Book Description
NCHRP report 600 explores human factors principles and findings for consideration by highway designers and traffic engineers. The report is designed to help the nonexpert in human factors to consider more effectively the roadway user's capabilities and limitations in the design and operation of highway facilities.
Placement of Detection Loops on High Speed Approaches to Traffic Signals
Author:
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 136
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.
Publisher:
ISBN:
Category : Detectors
Languages : en
Pages : 136
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.
Report
Author:
Publisher:
ISBN:
Category : Highway research
Languages : en
Pages : 230
Book Description
Publisher:
ISBN:
Category : Highway research
Languages : en
Pages : 230
Book Description
Traffic Signal Timing Manual
Author: U.s. Department of Transportation
Publisher: CreateSpace
ISBN: 9781508557173
Category : Transportation
Languages : en
Pages : 286
Book Description
This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.
Publisher: CreateSpace
ISBN: 9781508557173
Category : Transportation
Languages : en
Pages : 286
Book Description
This report serves as a comprehensive guide to traffic signal timing and documents the tasks completed in association with its development. The focus of this document is on traffic signal control principles, practices, and procedures. It describes the relationship between traffic signal timing and transportation policy and addresses maintenance and operations of traffic signals. It represents a synthesis of traffic signal timing concepts and their application and focuses on the use of detection, related timing parameters, and resulting effects to users at the intersection. It discusses advanced topics briefly to raise awareness related to their use and application. The purpose of the Signal Timing Manual is to provide direction and guidance to managers, supervisors, and practitioners based on sound practice to proactively and comprehensively improve signal timing. The outcome of properly training staff and proactively operating and maintaining traffic signals is signal timing that reduces congestion and fuel consumption ultimately improving our quality of life and the air we breathe. This manual provides an easy-to-use concise, practical and modular guide on signal timing. The elements of signal timing from policy and funding considerations to timing plan development, assessment, and maintenance are covered in the manual. The manual is the culmination of research into practices across North America and serves as a reference for a range of practitioners, from those involved in the day to day management, operation and maintenance of traffic signals to those that plan, design, operate and maintain these systems.
Guidelines for Timing Yellow and All-red Intervals at Signalized Intersections
Author: Hugh W. McGee
Publisher: Transportation Research Board
ISBN: 0309258596
Category : Traffic safety
Languages : en
Pages : 93
Book Description
TRB National Cooperative Highway Research Program (NCHRP) Report 731: Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections offers guidance for yellow change and all-red clearance intervals at signalized intersections. The guidelines provide a framework that can be easily applied by state and local transportation agencies.
Publisher: Transportation Research Board
ISBN: 0309258596
Category : Traffic safety
Languages : en
Pages : 93
Book Description
TRB National Cooperative Highway Research Program (NCHRP) Report 731: Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections offers guidance for yellow change and all-red clearance intervals at signalized intersections. The guidelines provide a framework that can be easily applied by state and local transportation agencies.
Traffic Control Systems Handbook
Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 670
Book Description
This handbook, which was developed in recognition of the need for the compilation and dissemination of information on advanced traffic control systems, presents the basic principles for the planning, design, and implementation of such systems for urban streets and freeways. The presentation concept and organization of this handbook is developed from the viewpoint of systems engineering. Traffic control studies are described, and traffic control and surveillance concepts are reviewed. Hardware components are outlined, and computer concepts, and communication concepts are stated. Local and central controllers are described, as well as display, television and driver information systems. Available systems technology and candidate system definition, evaluation and implementation are also covered. The management of traffic control systems is discussed.
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 670
Book Description
This handbook, which was developed in recognition of the need for the compilation and dissemination of information on advanced traffic control systems, presents the basic principles for the planning, design, and implementation of such systems for urban streets and freeways. The presentation concept and organization of this handbook is developed from the viewpoint of systems engineering. Traffic control studies are described, and traffic control and surveillance concepts are reviewed. Hardware components are outlined, and computer concepts, and communication concepts are stated. Local and central controllers are described, as well as display, television and driver information systems. Available systems technology and candidate system definition, evaluation and implementation are also covered. The management of traffic control systems is discussed.
Progress in Location-Based Services 2014
Author: Georg Gartner
Publisher: Springer
ISBN: 331911879X
Category : Science
Languages : en
Pages : 279
Book Description
This book presents a general picture of recent research activities related to location-based services. Such activities emerged in the last years especially concerning issues of outdoor/indoor positioning, smart environment, spatial modelling, personalization and context-awareness, cartographic communication, novel user interfaces, crowdsourcing, social media, big data analysis, usability and privacy. This book is comprised of a selection of the best papers presented during the 11th International Symposium on Location Based Services, which was held in Vienna (Austria) between 26th and 28th November 2014.
Publisher: Springer
ISBN: 331911879X
Category : Science
Languages : en
Pages : 279
Book Description
This book presents a general picture of recent research activities related to location-based services. Such activities emerged in the last years especially concerning issues of outdoor/indoor positioning, smart environment, spatial modelling, personalization and context-awareness, cartographic communication, novel user interfaces, crowdsourcing, social media, big data analysis, usability and privacy. This book is comprised of a selection of the best papers presented during the 11th International Symposium on Location Based Services, which was held in Vienna (Austria) between 26th and 28th November 2014.
The Image of the City
Author: Kevin Lynch
Publisher: MIT Press
ISBN: 9780262620017
Category : Architecture
Languages : en
Pages : 212
Book Description
The classic work on the evaluation of city form. What does the city's form actually mean to the people who live there? What can the city planner do to make the city's image more vivid and memorable to the city dweller? To answer these questions, Mr. Lynch, supported by studies of Los Angeles, Boston, and Jersey City, formulates a new criterion—imageability—and shows its potential value as a guide for the building and rebuilding of cities. The wide scope of this study leads to an original and vital method for the evaluation of city form. The architect, the planner, and certainly the city dweller will all want to read this book.
Publisher: MIT Press
ISBN: 9780262620017
Category : Architecture
Languages : en
Pages : 212
Book Description
The classic work on the evaluation of city form. What does the city's form actually mean to the people who live there? What can the city planner do to make the city's image more vivid and memorable to the city dweller? To answer these questions, Mr. Lynch, supported by studies of Los Angeles, Boston, and Jersey City, formulates a new criterion—imageability—and shows its potential value as a guide for the building and rebuilding of cities. The wide scope of this study leads to an original and vital method for the evaluation of city form. The architect, the planner, and certainly the city dweller will all want to read this book.