Statewide Roundabout Operations Monitoring And Evaluation

  • Principal Investigator: David Noyce TOPS Contact
  • Granting Agency: WisDOT
  • Researchers Andrea Bill and Madhav Chitturi


Statement of Work

Since the first modern roundabout in the United States was opened in 1990, the argument regarding its strengths and weaknesses has never stopped. Despite mixed perceptions from highway users, roundabouts have gradually gained popularity in Wisconsin. Currently there are over 150 roundabouts in Wisconsin, with about half of those on the state highway system. WisDOT also posted sample design standards from the Facilities Development Manual (FDM). Apparently, crash reductions are accompanied by significant improvements in traffic flow, thus reducing congestion and delays, air pollution, fuel consumption and so on. Intuitively, with roundabouts, potentially more severe crashes such as head-on, angle and left-turn crashes can be reduced or totally eliminated because vehicles travel in the same direction. Other safety benefits include the elimination of red-light running and overall low crash severity because of relatively low vehicular speed in roundabouts.

The feedback of driving through roundabouts can be dichotomic: to those who are familiar and comfortable with roundabout operations, it is a good experience; while to others who have never or rarely done it, the experience may be somewhat scary and uncomfortable. The conclusions and outcomes from other studies are strongly depended on the drivers studied or surveyed whose composition and attitude vary from state to state. One of the complaints of driving in a roundabout is its confusing and frightening, which is directly caused by drivers’ feeling and comprehension about the design and operations. The pros and cons of roundabouts over other means of traffic control in at-grade intersections are still of strong interests to both professionals and local residents and it is indispensable to study Wisconsin drivers’ reaction to roundabouts. The evaluation is aimed to comprehensively investigate the features of roundabout in terms of safety and operational functions, design, accessibility to vulnerable user group such as pedestrians, bicyclists and old users, and more importantly traffic safety. Wisconsin has the favor of years-long roundabout operation experience and relatively large sample size, which can provide robust evidence about Wisconsin roundabouts and complement existing literature in roundabout research.


Document Name Files Date Posted
Negotiation-Based Conflict Exposure Methodology in Roundabout Crash Pattern Analysis - presented at 2010 TRB, Washington DC Paper
Wisconsin Roundabout Evaluation (Phase 1) Executive Summary
Safety Memo
Vol 1 - Operations
Vol 2 - Safety
Wisconsin Roundabout Evaluation (Phase 2) Evaluation Safety Memo v2.0
Final Report - Phase 2