Author: Xingan David Kan
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Book Description
On-ramp metering at freeway bottlenecks is an effective method of reducing a freeway system's delay because empirical studies have previously shown that metering can prevent capacity drop, or reduction of outflow as a result of queue formation. However, arterial traffic signals that facilitate access to freeway on-ramps operate independent of the traffic conditions on the freeway on-ramp. Consequently, the traffic signals employ long signal cycle lengths and thus long green durations to maximize capacity at the arterial signalized intersections, which result in long platoons of freeway-bound traffic advancing toward the on-ramps. This often causes queue spillback on the freeway on-ramps and the surface street network. Queue override, a function that terminates or significantly relaxes the on-ramp metering rate whenever a sensor placed at the entrance of the on-ramp detects a potential queue spillover of the on-ramp vehicles on the adjacent surface streets, has become a widely accepted method of resolving queue spillback on the freeway on-ramps and nearby surface streets. Unfortunately, queue override releases the queue into the freeway and negates the benefit of ramp metering during the peak hours with recurrent freeway congestion. Video data collected downstream of freeway/on-ramp merge in San Jose, California show that the bottleneck discharge flow diminishes when queue override is activated for a sustained period of time. Observations over a two-week period suggest that queue override reduces the bottleneck discharge flow by an average of 10%. Recently, there has been significant interest in integrated corridor management (ICM) of facilities comprised of freeways and adjacent arterial streets. Significant benefits can be realized by preventing queue override and effectively storing the queued vehicles on the nearby arterial surface streets if the arterial traffic signals can account for traffic conditions on freeway on-ramps and avoid sending long platoons to the freeway on-ramp. A signal control strategy was developed and evaluated in this study. The algorithm takes available on-ramp storage and freeway ramp metering rate into account and dynamically reduces the cycle length and adjusts the green durations to prevent on-ramp queue spillback and mitigate unnecessary delay in the conflicting arterial directions. The proposed algorithm was tested through simulation and the results show that the proposed strategy reduces the freeway and system-wide delay even under fluctuations in traffic demand, at a modest penalty on the on-ramp bound traffic.
Increasing Freeway Capacity by Efficiently Timing Its Nearby Arterial Traffic Signals
Author: Xingan David Kan
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Book Description
On-ramp metering at freeway bottlenecks is an effective method of reducing a freeway system's delay because empirical studies have previously shown that metering can prevent capacity drop, or reduction of outflow as a result of queue formation. However, arterial traffic signals that facilitate access to freeway on-ramps operate independent of the traffic conditions on the freeway on-ramp. Consequently, the traffic signals employ long signal cycle lengths and thus long green durations to maximize capacity at the arterial signalized intersections, which result in long platoons of freeway-bound traffic advancing toward the on-ramps. This often causes queue spillback on the freeway on-ramps and the surface street network. Queue override, a function that terminates or significantly relaxes the on-ramp metering rate whenever a sensor placed at the entrance of the on-ramp detects a potential queue spillover of the on-ramp vehicles on the adjacent surface streets, has become a widely accepted method of resolving queue spillback on the freeway on-ramps and nearby surface streets. Unfortunately, queue override releases the queue into the freeway and negates the benefit of ramp metering during the peak hours with recurrent freeway congestion. Video data collected downstream of freeway/on-ramp merge in San Jose, California show that the bottleneck discharge flow diminishes when queue override is activated for a sustained period of time. Observations over a two-week period suggest that queue override reduces the bottleneck discharge flow by an average of 10%. Recently, there has been significant interest in integrated corridor management (ICM) of facilities comprised of freeways and adjacent arterial streets. Significant benefits can be realized by preventing queue override and effectively storing the queued vehicles on the nearby arterial surface streets if the arterial traffic signals can account for traffic conditions on freeway on-ramps and avoid sending long platoons to the freeway on-ramp. A signal control strategy was developed and evaluated in this study. The algorithm takes available on-ramp storage and freeway ramp metering rate into account and dynamically reduces the cycle length and adjusts the green durations to prevent on-ramp queue spillback and mitigate unnecessary delay in the conflicting arterial directions. The proposed algorithm was tested through simulation and the results show that the proposed strategy reduces the freeway and system-wide delay even under fluctuations in traffic demand, at a modest penalty on the on-ramp bound traffic.
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Book Description
On-ramp metering at freeway bottlenecks is an effective method of reducing a freeway system's delay because empirical studies have previously shown that metering can prevent capacity drop, or reduction of outflow as a result of queue formation. However, arterial traffic signals that facilitate access to freeway on-ramps operate independent of the traffic conditions on the freeway on-ramp. Consequently, the traffic signals employ long signal cycle lengths and thus long green durations to maximize capacity at the arterial signalized intersections, which result in long platoons of freeway-bound traffic advancing toward the on-ramps. This often causes queue spillback on the freeway on-ramps and the surface street network. Queue override, a function that terminates or significantly relaxes the on-ramp metering rate whenever a sensor placed at the entrance of the on-ramp detects a potential queue spillover of the on-ramp vehicles on the adjacent surface streets, has become a widely accepted method of resolving queue spillback on the freeway on-ramps and nearby surface streets. Unfortunately, queue override releases the queue into the freeway and negates the benefit of ramp metering during the peak hours with recurrent freeway congestion. Video data collected downstream of freeway/on-ramp merge in San Jose, California show that the bottleneck discharge flow diminishes when queue override is activated for a sustained period of time. Observations over a two-week period suggest that queue override reduces the bottleneck discharge flow by an average of 10%. Recently, there has been significant interest in integrated corridor management (ICM) of facilities comprised of freeways and adjacent arterial streets. Significant benefits can be realized by preventing queue override and effectively storing the queued vehicles on the nearby arterial surface streets if the arterial traffic signals can account for traffic conditions on freeway on-ramps and avoid sending long platoons to the freeway on-ramp. A signal control strategy was developed and evaluated in this study. The algorithm takes available on-ramp storage and freeway ramp metering rate into account and dynamically reduces the cycle length and adjusts the green durations to prevent on-ramp queue spillback and mitigate unnecessary delay in the conflicting arterial directions. The proposed algorithm was tested through simulation and the results show that the proposed strategy reduces the freeway and system-wide delay even under fluctuations in traffic demand, at a modest penalty on the on-ramp bound traffic.
Real-Time Arterial Traffic Signal Performance Measures
Author: Christopher M. Day
Publisher: Purdue University Press
ISBN: 9781622600908
Category : Transportation
Languages : en
Pages : 244
Book Description
Increasing demand for highway system capacity compels transportation agencies to extract as much capacity as possible from existing systems. Traffic signals represent a major component of highway systems. Improvement of traffic signal operation requires accurate performance measures. Despite recent improvements in computing technology, traffic signal controllers are currently not able to capture useful performance measures on a cycle-by-cycle basis. This report presents a set of performance measures that could be collected on a cycle-by-cycle basis by a traffic signal controller given the capability to log phase indications and detector actuations. The performance measures investigated here include the volume-to-capacity ratio and arrival type defined by the Highway Capacity Manual. The effectiveness of these performance measures in evaluating operation at a traffic signal is demonstrated in two comparative case studies. The first study investigates the impact of actuating a portion of the coordinated phases at a coordinated arterial intersection. The second study investigates the results of retiming a traffic signal on a coordinated arterial.
Publisher: Purdue University Press
ISBN: 9781622600908
Category : Transportation
Languages : en
Pages : 244
Book Description
Increasing demand for highway system capacity compels transportation agencies to extract as much capacity as possible from existing systems. Traffic signals represent a major component of highway systems. Improvement of traffic signal operation requires accurate performance measures. Despite recent improvements in computing technology, traffic signal controllers are currently not able to capture useful performance measures on a cycle-by-cycle basis. This report presents a set of performance measures that could be collected on a cycle-by-cycle basis by a traffic signal controller given the capability to log phase indications and detector actuations. The performance measures investigated here include the volume-to-capacity ratio and arrival type defined by the Highway Capacity Manual. The effectiveness of these performance measures in evaluating operation at a traffic signal is demonstrated in two comparative case studies. The first study investigates the impact of actuating a portion of the coordinated phases at a coordinated arterial intersection. The second study investigates the results of retiming a traffic signal on a coordinated arterial.
Active Traffic Management for Arterials
Author: Richard Gerhard Dowling
Publisher: Transportation Research Board
ISBN: 0309223970
Category : Traffic congestion
Languages : en
Pages : 65
Book Description
"Active traffic management (ATM) includes a suite of traffic management and control strategies that improve operational efficiency. These strategies are used to manage traffic flow to enhance capacity and safety. This synthesis documents the state of the practice associated with designing, implementing, and operating ATM on arterial roadways."--Preface.
Publisher: Transportation Research Board
ISBN: 0309223970
Category : Traffic congestion
Languages : en
Pages : 65
Book Description
"Active traffic management (ATM) includes a suite of traffic management and control strategies that improve operational efficiency. These strategies are used to manage traffic flow to enhance capacity and safety. This synthesis documents the state of the practice associated with designing, implementing, and operating ATM on arterial roadways."--Preface.
Increasing Traffic Capacity of Arterial Streets
Author: National Research Council (U.S.). Highway Research Board
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 80
Book Description
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 80
Book Description
Road Vehicle Automation 6
Author: Gereon Meyer
Publisher: Springer
ISBN: 3030229335
Category : Technology & Engineering
Languages : en
Pages : 144
Book Description
This is the sixth volume of a sub series on Road Vehicle Automation published within the Lecture Notes in Mobility. The contents have been provided by researchers, engineers and analysts from all around the world. Topics covered include public sector activities, human factors and challenges, ethical, legal, energy and technology perspectives, vehicle systems development, as well as transportation infrastructure and planning. The book is based on the Automated Vehicles Symposium held on July 9-12, 2018 in San Francisco, CA (USA).
Publisher: Springer
ISBN: 3030229335
Category : Technology & Engineering
Languages : en
Pages : 144
Book Description
This is the sixth volume of a sub series on Road Vehicle Automation published within the Lecture Notes in Mobility. The contents have been provided by researchers, engineers and analysts from all around the world. Topics covered include public sector activities, human factors and challenges, ethical, legal, energy and technology perspectives, vehicle systems development, as well as transportation infrastructure and planning. The book is based on the Automated Vehicles Symposium held on July 9-12, 2018 in San Francisco, CA (USA).
Traffic Signal Retiming Practices in the United States
Author: Robert L. Gordon
Publisher: Transportation Research Board
ISBN: 0309143179
Category : Technology & Engineering
Languages : en
Pages : 92
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 409: Traffic Signal Retiming Practices in the United States explores practices that operating agencies currently use to revise traffic signal timing. The report examines the processes used to develop, install, verify, fine-tune, and evaluate the plans--
Publisher: Transportation Research Board
ISBN: 0309143179
Category : Technology & Engineering
Languages : en
Pages : 92
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 409: Traffic Signal Retiming Practices in the United States explores practices that operating agencies currently use to revise traffic signal timing. The report examines the processes used to develop, install, verify, fine-tune, and evaluate the plans--
Arterial-street Signal Timing Strategies to Provide Additional Through-traffic Capacity During Freeway Incident Conditions
Author: James Joseph Dale
Publisher:
ISBN:
Category : Traffic engineering
Languages : en
Pages : 250
Book Description
Publisher:
ISBN:
Category : Traffic engineering
Languages : en
Pages : 250
Book Description
Highway Noise; a Design Guide for Highway Engineers
Author: Bolt, Beranek, and Newman
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 840
Book Description
Various methods of assessing noise, loudness, and noise annoyance are reviewed and explained; sources, types, and intensities of traffic noise are noted; typical means of abatement and attenuation are described; design criteria for various land uses ranging from low-density to industrial are suggested and compared with the results of previous BBN and British systems for predicting annoyance and complaint; and a design guide for predicting traffic noise, capable of being programmed for batch and on-line computer applications, is presented in form suitable for use as a working tool. A flow diagram describes the interrelationships of elements in the traffic noise prediction methodology, and each element is discussed in detail in the text. The text is presented of a tape recording that takes the listener through a series of traffic situations, with such variables as traffic distance, flow velocity, distance, outdoors and indoors, and presence or absence of absorbers and attenuators.
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 840
Book Description
Various methods of assessing noise, loudness, and noise annoyance are reviewed and explained; sources, types, and intensities of traffic noise are noted; typical means of abatement and attenuation are described; design criteria for various land uses ranging from low-density to industrial are suggested and compared with the results of previous BBN and British systems for predicting annoyance and complaint; and a design guide for predicting traffic noise, capable of being programmed for batch and on-line computer applications, is presented in form suitable for use as a working tool. A flow diagram describes the interrelationships of elements in the traffic noise prediction methodology, and each element is discussed in detail in the text. The text is presented of a tape recording that takes the listener through a series of traffic situations, with such variables as traffic distance, flow velocity, distance, outdoors and indoors, and presence or absence of absorbers and attenuators.
Traffic Control on Arterial Streets
Author:
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 502
Book Description
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 502
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.