Examining Speed Selection and Driver Yielding Behavior Toward Pedestrians and Bicyclists at Roundabouts

Roundabouts have been shown to significantly improve safety, in part because of there being fewer conflict points between road users and lower travel speeds as compared to other intersection designs. However, crossing a roundabout on foot or by bicycle introduces a different set of risks and requires drivers to yield to these other road users. Lower yielding rates may increase the risks of pedestrian and bicyclist crash involvement, particularly at the roundabout entrance or exit. To investigate these concerns, this study evaluates driver yielding behavior when encountering pedestrians and bicyclists at roundabout entry and exit approaches. Additional analyses compare vehicle speeds on the entry approach in the presence and absence of pedestrians and bicyclists at the roundabout crossing. Crossing events were staged at 16 roundabouts in Minnesota, and driver yielding behavior toward vulnerable road users (VRUs) was captured through video cameras. At nine of these sites, the speed profiles of vehicles entering the roundabout were also captured using lidar guns. Mixed effects logistic and multiple linear regression models were developed to investigate factors affecting yielding behavior and speed selection under various scenarios. The results showed differences in yielding behavior at the roundabout entry and exit. The results also varied based on crossing direction, roundabout geometry, and the presence of rectangular rapid flashing beacons. The results also showed differences in speed selection behavior based on whether a VRU was waiting to cross at roundabout entry and the response of the driver to VRU presence.