Multilane Roundabout Safety

Roundabout Safety

The Wisconsin Department of Transportation (WisDOT) is a national leader in roundabout implementation with over 250 roundabouts built in the state and over 150 in the planning phase (

WisDOT and the University of Wisconsin Traffic Operations and Safety (TOPS) Lab have worked together on eight different roundabout studies over the last several years to better understand various elements of roundabout design, operations, maintenance and safety. The TOPS Lab conducted safety analyses of roundabouts on the Wisconsin state system in 2009 and conducted a phase 2 study in 2012. Currently, TOPS Lab is performing Phase 3 of safety research. Please refer to the project page for more information. TOPS team also collected video data at several multilane roundabouts in WI and identified causes for crashes at multilane roundabouts.

Incorrect Lane Choice

Lane Change in Circulating Lanes

Wrong Yielding

Failure to Yield to All Circulating Lanes


  • Dongxi Zheng, Xiao Qin, Ross Tillman, and David A. Noyce. Measuring Modern Roundabout Traffic Conflict Exposure. Journal of Transportation Safety and Security, Vol. 5(3), pp. 208-223, 2013. [pdf
  • Xiao Qin, Ghazan Khan, Andrea Bill, and David A. Noyce. Comprehensive Safety Evaluation of Roundabouts in Wisconsin. Journal of Transportation Safety & Security, Vol. 3(4), pp 289-303, 2014. [pdf]
  • Ghazan Khan, Andrea Bill, David Chiu, and David Noyce. Safety Evaluation of Wisconsin Roundabouts: Phase 2, 2013 [pdf]
  • Andrea Bill, Xiao Qin, Madhav Chitturi, and David A. Noyce. Comprehensive Evaluation of Wisconsin Roundabouts Volume 2: Safety Findings, 2011. [pdf]

Roundabout Operations

SHRP2 Data Processing