Developing Safety Performance Measures for Roundabout Applications in the State of Oregon

This report documents the research effort to quantify the safety performance of roundabouts in the State of Oregon. The primary goal of this research is to provide the Oregon Department of Transportation (ODOT) with safety performance functions (SPFs) that can be used to evaluate the safety performance of single-lane, four-leg roundabouts. These safety metrics generally conform to the statistical models and methodologies similar to those outlined in the Highway Safety Manual (HSM) published in 2010 by the American Association of State Highway and Transportation Officials (AASHTO).