Operational Effects of U-Turns as Alternatives to Direct Left-Turns
Publication: Journal of Transportation Engineering
Volume 133, Issue 5
Abstract
This study analyzed the operational effects of a widely used access management treatment: using U-turns as alternatives to direct left-turns from driveways. Data were collected at 34 selected roadway segments in central Florida. Delay and travel time were compared for various driveway left-turn alternatives under different levels of driveway volume and major road through traffic volume. The left-turn alternatives considered include direct left-turns (DLT), right-turns followed by U-turns (RTUT) at median openings, and right-turns followed by U-turns at signalized intersections. A binary logit model was developed to estimate how many drivers would like to make a RTUT instead of a DLT under different traffic and roadway geometric conditions. It was found that vehicles making RTUT at a downstream median opening before a signalized intersection have comparable total travel time as compared with those making DLT at a driveway; and the percentage of drivers selecting RTUT increases with the upstream through traffic volume, left-turn volume from major road into the driveway, and the total left-turn traffic demand at a driveway.
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Acknowledgments
This research was sponsored by the Florida Department of Transportation. The assistance provided by FDOT is greatly appreciated. The writers also would like to thank the Graduate Research Assistants at the Department of Civil and Environmental Engineering of the University of South Florida for their assistance in field data collection and data reduction. Specifically, the writers would like to express thanks to Kristine Williams, Dr. Sunanda Dissanayake, and Dr. Juan Pernia for their technical support and guidance.
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Information & Authors
Information
Published In
Journal of Transportation Engineering
Volume 133 • Issue 5 • May 2007
Pages: 327 - 334
Copyright
© 2007 ASCE.
History
Received: Jan 24, 2006
Accepted: Oct 31, 2006
Published online: May 1, 2007
Published in print: May 2007
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