Study Details

Study Title: Traffic Safety Evaluation of Pedestrians and Bicyclists at Roundabouts in Minnesota

Authors: Wagner et al.

Publication Date:OCT, 2023

Abstract: By the end of 2022, nearly 450 roundabouts were installed on Minnesota roadways. An evaluation of traffic safety at roundabouts published by MnDOT in 2017 showed substantial decreases in fatal and serious injury crashes for all users at intersections after installation of a roundabout. The safety effects of roundabouts are largely due to geometric design practices that reduce the speed of motorized vehicles as they approach and travel through the intersection. The purpose of this evaluation is to determine if the safety effects seen in the 2017 evaluation still apply to roundabouts with higher levels of use by pedestrians and bicyclists. This evaluation conducts a before-after analysis of 95 roundabouts in Minnesota and an analysis comparing roundabouts to untreated intersections. With the installation of a roundabout, this study finds that the before-after analysis results in a 40% decrease in all severity injury crashes for all roadway users, a 70% decrease in fatal and serious injury crashes for bikes and pedestrians, and a 15% decrease in total pedestrian bike and pedestrian crashes. The results of the comparison analyses suggest roundabouts have better safety performance than through-stop and traffic signal-controlled intersections and similar safety performance to locations with all-way stop control. The results of this evaluation thus indicate that roundabouts can be an effective safety treatment for pedestrian and bicycle crashes.

Study Citation: Wagner, M., D. Leuer, E. DeVoe, I Saari, and M. Anderson. "Traffic Safety Evaluation of Pedestrians and Bicyclists at Roundabouts in Minnesota." Report No. MN 2023-36. Minnesota Department of Transportation. St. Paul, Minnesota. (2023).

Study Report: Download the Study Report Document


CMFs Associated With This Study

Category: Intersection geometry

Countermeasure: Convert intersection to roundabout

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.53646.42 StarsAllK,ANot specifiedAll
0.60139.93 StarsAllK,A,B,CNot specifiedAll
1.38-382 StarsAllAllNot specifiedAll
0.29770.32 StarsVehicle/bicycle, Vehicle/pedestrianK,ANot specifiedAll
0.82117.92 StarsVehicle/bicycle, Vehicle/pedestrianK,A,B,CNot specifiedAll
0.84915.12 StarsVehicle/bicycle, Vehicle/pedestrianAllNot specifiedAll