01701843

Component

https://doi.org/10.1177/0361198119840341

U-turn lanes are commonly provided at at-grade diamond interchanges with frontage roads to reduce delays for U-turning traffic and for the interchange as a whole; however, there are currently many unknowns related to their design, operation, and use. Researchers of this study assessed the existing practice of U-turn implementation by evaluating operations of U-turn lanes at 25 diamond interchanges in Texas through field data collection and simulation analysis. Researchers determined the performance and limitations of U-turn lanes under various geometric and operational conditions, identified and investigated several factors affecting U-turn lane use, and determined the anticipated effectiveness of proposed solutions to U-turn operational issues. This paper provides implementable guidelines for designing and operating U-turn lanes at diamond interchanges. Among the ten countermeasures studied in this paper, closing nearby driveways, adding acceleration lane for U-turn departures, and separating U-turn departures from conflicting traffic using pylons were found to be effective solutions to improve U-turn operations.

19-02676

English

pp 627-639

2019-4

Transportation Research Record: Journal of the Transportation Research Board

Digital/other

Figures (6) ; References (20) ; Tables (5)

At grade intersections; Countermeasures; Data collection; Diamond interchanges; Evaluation; Highway operations; Signalized intersections; Traffic data; U turns

Texas

Highways; Operations and Traffic Management

TRIS, TRB, ATRI

Mar 13 2019 2:13PM