Study Details

Study Title: Modeling the Effect of Road Surface Friction on the Accident Rate of Urban Un-Signalized Intersections

Authors: Amini and Beigi

Publication Date:JAN, 2015

Abstract: Urban intersections are among the most accident prone locations. There are many factors affecting intersection safety such as traffic, environmental and behavioral conditions, and geometric design. Road surface characteristics particularly skid resistance of surface, play a major role in the accident rate of intersections. The main objective of this paper was to identify the relationship between rate of accidents at intersections and the road surface skid resistance based on an experimental approach. Field studies were conducted on a selected sample of un-signalized intersections to gather the needed data including road surface skid resistance, and speed and volume of traffic at major and minor streets which were supposed to be the main affecting variables in the model. Nearly 200 crashes occurring at these intersections in wet conditions were analyzed. Data analysis indicated that skid resistance was at the lowest level in intersections with the highest accident rate. To obtain a relationship between skid resistance and accident rate, a log-linear regression model was developed and validated. According to the model it is expected that for each 1% increase in surface skid resistance, a 7.5% reduction in rate of accidents could be achieved. The model may be used as a predictive tool of safety performance for un-signalized intersections.

Study Citation: Amini, B. and H. Beigi. "Modeling the Effect of Road Surface Friction on the Accident Rate of Urban Un-Signalized Intersections". Presented at the 94th Annual Meeting of the Transportation Research Board, Paper No. 15-2823, Washington, D.C., (2015).


CMFs Associated With This Study

Category: Roadway

Countermeasure: Increase pavement friction from F1 to F2

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
CMF EquationCRF Equation2 StarsWet roadA,B,C,ONot specifiedUrban