May 22


Sight Distance for U-Turns

By Mike Spack

May 22, 2014

Gary Sokolow at the Florida DOT sent Bryant and I a nice note about Bryant’s post on When U Turns Should be Included in Traffic Analyses.  Gary sent us the exhibit below for designing left turn lanes to accommodate u-turns.

I couldn’t find u-turn sight distance being accounted for in MnDOT’s design guides.  This is a great resource for all of us.

The diagram is from the DOT’s Median Handbook and Gary wants to be clear on this point:  this exhibit is a suggestion and has never been made official.  Gary also sent along Dr. Virgil Stover’s, Texas Transportation Institute, calculations that led to this diagram in case anyone is interested in digging into the assumptions and math behind the exhibit –Virgil Stover handwritten notes on u turn sight distance.

U-Turn Design Exhibit


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Mike Spack

My mission is to help traffic engineers, transportation planners, and other transportation professionals improve our world.

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