Warrants for Right-turn Lanes/treatments on Two-lane Roads

Warrants for Right-turn Lanes/treatments on Two-lane Roads PDF Author: Amiy Varma
Publisher:
ISBN:
Category : Right-turn lanes
Languages : en
Pages : 194

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Book Description
The goal of this project was to analyze geometric, speed, volume, and crash data for a broad range of conditions with the ultimate objective of establishing bases for warrants for right-turn lanes on two-lane roads where major approach did not have any controls. Right-turn lane guidelines for this contest is not clear and convincing. Safety effectiveness and savings were estimated using extensive data examination and analysis of crash data, several statistical models that were developed using crash data, and a conflict model, which was developed using field data. It was found that not all accidents are eliminated with use of right-turn lane. However, right-turn lanes were effective in improving safety. More interesting was the finding that safety effectiveness of right-turn lanes was more at driveways than at intersections. Operational effectiveness was estimated using a delay model and a fuel consumption model, which were developed using field data, simulation software (CORSIM®), and statistical software, Minitab®. The volume thresholds that varied with changes in right-turn lane cost and fuel cost were provided as alternative scenarios for warrants. The warrants established here will be helpful in decision-making regarding whether to implement a right-turn lane or not on two-lane roads.

Warrants for Right-turn Lanes/treatments on Two-lane Roads

Warrants for Right-turn Lanes/treatments on Two-lane Roads PDF Author: Amiy Varma
Publisher:
ISBN:
Category : Right-turn lanes
Languages : en
Pages : 194

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Book Description
The goal of this project was to analyze geometric, speed, volume, and crash data for a broad range of conditions with the ultimate objective of establishing bases for warrants for right-turn lanes on two-lane roads where major approach did not have any controls. Right-turn lane guidelines for this contest is not clear and convincing. Safety effectiveness and savings were estimated using extensive data examination and analysis of crash data, several statistical models that were developed using crash data, and a conflict model, which was developed using field data. It was found that not all accidents are eliminated with use of right-turn lane. However, right-turn lanes were effective in improving safety. More interesting was the finding that safety effectiveness of right-turn lanes was more at driveways than at intersections. Operational effectiveness was estimated using a delay model and a fuel consumption model, which were developed using field data, simulation software (CORSIM®), and statistical software, Minitab®. The volume thresholds that varied with changes in right-turn lane cost and fuel cost were provided as alternative scenarios for warrants. The warrants established here will be helpful in decision-making regarding whether to implement a right-turn lane or not on two-lane roads.

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.

Development of Warrants for Left-turn Lanes

Development of Warrants for Left-turn Lanes PDF Author: Kenneth R. Agent
Publisher:
ISBN:
Category : Road markings
Languages : en
Pages : 44

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Book Description


Volume Warrants for Left-turn Lanes at Unsignalized Grade Intersections

Volume Warrants for Left-turn Lanes at Unsignalized Grade Intersections PDF Author: M. D. Harmelink
Publisher:
ISBN:
Category : Left-turn lanes
Languages : en
Pages : 72

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Development of Left-turn Lane Warrants for Unsignalized Intersections

Development of Left-turn Lane Warrants for Unsignalized Intersections PDF Author:
Publisher:
ISBN:
Category : Left-turn lanes
Languages : en
Pages :

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Book Description
Left-turn movements at intersections, including driveways - especially movements that are made from lanes that are shared with through traffic - cause delays and adversely impact safety. Although left-turn warrants have been updated, many agencies still use research performed by M. Harmelink from the mid-1960s. While most states use procedures that are based on Harmelink, a number of limitations of Harmelink's procedure have been identified. Economic analysis can provide a useful method for combining traffic operations and safety benefits of left-turn lanes to identify situations in which left-turn lanes are and are not justified economically. This project used a benefit-cost approach to determine when a left-turn lane would be justified. The steps included simulation to determine delay savings from installing a left-turn lane, crash costs and crash reduction savings determined from safety performance functions and accident modification factors available in the "Highway Safety Manual," and construction costs. Left-turn lane warrants were developed for rural two-lane highways, rural four-lane highways, and urban and suburban roadways. In addition, warrants for bypass lanes were developed for rural two-lane highways. A "Design Guide on Left-Turn Accommodations at Unsignalized Intersections" was developed that discusses left-turn lane designs, traffic control treatments, and case study examples.

Development of Warrants for Left-turn Phasing

Development of Warrants for Left-turn Phasing PDF Author: Kenneth R. Agent
Publisher:
ISBN:
Category : Electronic traffic controls
Languages : en
Pages : 48

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Volume Warrant for Free Right-turn Lanes at Unsignalized Intersections on Rural Two-lane Highways

Volume Warrant for Free Right-turn Lanes at Unsignalized Intersections on Rural Two-lane Highways PDF Author: Patrick T. McCoy
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 33

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Left-turn Accommodations at Unsignalized Intersections

Left-turn Accommodations at Unsignalized Intersections PDF Author: Kay Fitzpatrick
Publisher: Transportation Research Board
ISBN: 0309258987
Category : Left-turn lanes
Languages : en
Pages : 62

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Book Description
"TRB's National Cooperative Highway Research Program (NCHRP) Report 745: Left-Turn Accommodations at Unsignalized Intersections presents guidance for the selection and design of left-turn accommodations at unsignalized intersections. The report includes 11 case studies of typical situations that illustrate the use of the guidance." -- publisher's description.

Accident Mitigation Guide for Congested Rural Two-lane Highways

Accident Mitigation Guide for Congested Rural Two-lane Highways PDF Author: Kay Fitzpatrick
Publisher: Transportation Research Board
ISBN: 9780309066242
Category : Transportation
Languages : en
Pages : 176

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Book Description


Warrants for Exclusive Left Turn Lanes at Unsignalized Intersections and Driveways

Warrants for Exclusive Left Turn Lanes at Unsignalized Intersections and Driveways PDF Author:
Publisher:
ISBN:
Category : Left-turn lanes
Languages : en
Pages : 140

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Book Description