Author(s):
J.M. Tydlacka, H. Zhou, K.K. Dixon, R.E. Avelar Moran, L. Ding, S.P. Venglar, N.A. Chaudhary, M.A. Brewer
Publication Date
September 2017
Abstract
U-turn lanes are commonly provided at diamond interchanges 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. This project provides the Texas Department of Transportation (TxDOT) with implementable guidelines for designing and operating U-turn lanes at diamond interchanges. Researchers identified and investigated several factors affecting U-turn lane use, determined the performance and limitations of U-turn lanes under various geometric and operational conditions, and determined the anticipated effectiveness of proposed solutions to U-turn operational issues. Researchers then developed and structured guidelines for inclusion in the TxDOT Roadway Design Manual and other manuals addressing access management, design, and operations of U-turn facilities. This investigative effort included a cross-sectional safety analysis of existing U-turn configurations that provided valuable insight into factors contributing to U-turn safety. Along with the safety analysis, researchers developed a self-calculating spreadsheet tool that can be used to predict U-turn safety performance under various conditions.
Report Number:
0-6894-1
Link(s):
Document/Product
http://tti.tamu.edu/documents/0-6894-1.pdf
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