详情

原文传递 Development of Left-Turn Lane Warrants for Unsignalized Intersections.

题名：	Development of Left-Turn Lane Warrants for Unsignalized Intersections.
作者：	Brewer, M. A.; Eisele, W. L.; Fitzpatrick, K.; Gluck, J. S.; Zhang, Y.
关键词：	Case Studies; Intersections; Left Turn Lanes; Performance Measures; Roadways; Safety Benefits; Traffic Control; Traffic Demands; Traffic Engineers; Traffic Signal Warrants
摘要：	Left-turn movements at intersections, including drivewaysespecially movements that are made from lanes that are shared with through trafficcause 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 Harmelinks procedure have been identified. Economic analysis can provide a useful method for combining traffic operations and safety benefits of leftturn 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.
报告类型：	科技报告