Development of Left-Turn Lane Warrants for Unsignalized Intersections Academic Article uri icon

abstract

  • Left-turn movements at intersections, including drivewaysespecially movements that are made from lanes that are shared with through trafficcause delays and adversely affect safety. Although some left-turn warrants have been updated, many agencies still use research performed by M. D. Harmelink in the mid-1960s. Most states use procedures that are based on Harmelink's work, but several limitations 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 either are or are not justified economically. This project used a benefitcost 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 crash 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.

published proceedings

  • TRANSPORTATION RESEARCH RECORD

author list (cited authors)

  • Fitzpatrick, K., Brewer, M. A., Eisele, W. L., Zhang, Y., Gluck, J. S., Levinson, H. S., & Iragavarapu, V.

citation count

  • 1

complete list of authors

  • Fitzpatrick, Kay||Brewer, Marcus A||Eisele, William L||Zhang, Yunlong||Gluck, Jerome S||Levinson, Herbert S||Iragavarapu, Vichika

publication date

  • January 2012