Development, Evaluation and Application of Left Turn Signal Warrants

Development, Evaluation and Application of Left Turn Signal Warrants PDF Author: Jonathan Upchurch
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 220

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This study dealt with five types of left turn signal phasing: permissive, leading exclusive, lagging exclusive, leading exclusive/permissive, and lagging exclusive/permissive. The objectives of this research project were to: (1) develop a research work plan to conduct a statistically valid study for the development of numerical warrants for left turn movements; and (2) prepare a database of available information on signalized intersections and select the intersections to be used in the future study. This report describes the database of Arizona signalized intersections created in this project, the findings on left turn accident rates for different types of left turn phasing (using a nonrandom sample), and results of a validation study of the TEXAS computer simulation model. It also presents a research work plan for a future research project.

Development, Evaluation and Application of Left Turn Signal Warrants

Development, Evaluation and Application of Left Turn Signal Warrants PDF Author: Jonathan Upchurch
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 220

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Book Description
This study dealt with five types of left turn signal phasing: permissive, leading exclusive, lagging exclusive, leading exclusive/permissive, and lagging exclusive/permissive. The objectives of this research project were to: (1) develop a research work plan to conduct a statistically valid study for the development of numerical warrants for left turn movements; and (2) prepare a database of available information on signalized intersections and select the intersections to be used in the future study. This report describes the database of Arizona signalized intersections created in this project, the findings on left turn accident rates for different types of left turn phasing (using a nonrandom sample), and results of a validation study of the TEXAS computer simulation model. It also presents a research work plan for a future research project.

Evaluation of Safety and Development of Guidelines for Protected/permitted Left-turn Signal Controls

Evaluation of Safety and Development of Guidelines for Protected/permitted Left-turn Signal Controls PDF Author: Zongzhong Tian
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 106

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Evaluation of the Left Turn Red Arrow

Evaluation of the Left Turn Red Arrow PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 58

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Highway Research Abstracts

Highway Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Highway engineering
Languages : en
Pages : 1006

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Evaluation of Traffic Signal Displays for Protected/permissive Left-turn Control

Evaluation of Traffic Signal Displays for Protected/permissive Left-turn Control PDF Author: Christopher Lynn Brehmer
Publisher: Transportation Research Board
ISBN: 0309087570
Category : Information display systems
Languages : en
Pages : 94

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Estimated Highway Planning and Research Program

Estimated Highway Planning and Research Program PDF Author:
Publisher:
ISBN:
Category : Highway planning
Languages : en
Pages : 240

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Development of Warrants for Installation of Dual Right-turn Lanes at Signalized Intersections

Development of Warrants for Installation of Dual Right-turn Lanes at Signalized Intersections PDF Author: Yi Qi
Publisher:
ISBN:
Category : Right-turn lanes
Languages : en
Pages : 126

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Book Description
Right-turn lanes provide space for the deceleration and storage of right-turn vehicles, and separate turning vehicles from through movements. Dual right-turn lanes are increasingly used at urban intersections primarily for two reasons: (1) to accommodate high right-turn demands and avoid turn-pocket overflows, and/or (2) to prevent right-turn vehicles that exit from a nearby upstream freeway off-ramp (on the left of the roadway) from abruptly changing too many lanes toward the right-turn lane at the intersection. In addition, a number of other factors may affect the decisions on the installation of dual right-turn lanes. However, warrants for dual right lane installation are almost non-existent, leaving traffic engineers to rely on engineering judgment. This research aims to develop warrants for installation of dual right-turn lanes at signalized intersections. Both the operational and safety benefits/costs were analyzed by surveying traffic engineers and by conducting traffic simulation-based analysis. Microscopic traffic simulation model, VISSIM, was used to quantify the operation benefits and Surrogate Safety Assessment Model (SSAM) developed by Siemens was used to analyze the safety gains due to installation of dual right-turn lanes.

Federally Coordinated Program of Highway Research, Development, and Technology. Annual Progress Report. Fiscal Year 1985

Federally Coordinated Program of Highway Research, Development, and Technology. Annual Progress Report. Fiscal Year 1985 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 704

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Impacts on Safety of Left-turn Treatment at High Speed Signalized Intersections

Impacts on Safety of Left-turn Treatment at High Speed Signalized Intersections PDF Author: T. H. Maze
Publisher:
ISBN:
Category : Left-turn lanes
Languages : en
Pages : 94

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Book Description
Left-turning traffic is a major source of conflicts at intersections. Though an average of only 10% to 15% of all approach traffic turns left, these vehicles are involved in approximately 45% of all accidents. This report presents the results of research conducted to develop models which estimate approach accident rates at high speed signalized intersections. The objective of the research was to quantify the relationship between traffic and intersection characteristics, and accident potential of different left turn treatments. Geometric, turning movement counts, and traffic signal phasing data were collected at 100 intersections in Iowa using a questionnaire sent to municipalities. Not all questionnaires resulted in complete data and ultimately complete data were derived for 63 intersections providing a database of 248 approaches. Accident data for the same approaches were obtained from the Iowa Department of Transportation Accident Location and Analysis System (ALAS). Regression models were developed for two different dependent variables: 1) the ratio of the number of left turn accidents per approach to million left turning vehicles per approach, and 2) the ratio of accidents per approach to million traffic movements per approach. A number of regression models were developed for both dependent variables. One model using each dependent variable was developed for intersections with low, medium, and high left turning traffic volumes. As expected, the research indicates that protected left turn phasing has a lower accident potential than protected/permitted or permitted phasing. Left turn lanes and multiple lane approaches are beneficial for reducing accident rates, while raised medians increase the likelihood of accidents. Signals that are part of a signal system tend to have lower accident rates than isolated signals. The resulting regression models may be used to determine the likely impact of various left turn treatments on intersection accident rates. When designing an intersection approach, a traffic engineer may use the models to estimate the accident rate reduction as a result of improved lane configurations and left turn treatments. The safety benefits may then be compared to any costs associated with operational effects to the intersection (i.e., increased delay) to determine the benefits and costs of making intersection safety improvements.

Federally Coordinated Program of Highway Research, Development and Technology

Federally Coordinated Program of Highway Research, Development and Technology PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 838

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