Study Details

Study Title: Safety Effects of Turning Movement Restrictions at Stop-Controlled Intersections

Authors: Le et al.

Publication Date: JAN, 2018

Abstract: This study evaluates the safety effectiveness of physical right-in-right-out (RIRO) operations compared to full turning movements at stop-controlled intersections. Geometric, traffic, and crash data from California were obtained for urban, three-legged, stop-controlled intersections with full movement and RIRO operations, as well as the downstream four-legged, stop-controlled or signalized intersections with full movement. A cross-sectional analysis provided estimates of the effects of turning movement restrictions while controlling for other differences between sites with RIRO and full movement. The aggregate results indicate reductions in total, all intersection-related, and fatal and injury intersection-related crashes at intersections with RIRO operations compared to full movement with estimated CMFs of 0.55, 0.32, and 0.20, respectively. The reductions are statistically significant at the 95-percent confidence level for all crash types. Based on the disaggregate results, it does not appear that RIRO operations have different effects for different levels of traffic, design speed, or number of lanes. The analysis also examined the potential for crash migration from intersections where RIRO is implemented to the downstream intersection when determining the net benefits. The results indicate potential crash increases at downstream intersections, but many of the increases are not statistically significant at the 90-percent confidence level. While the safety benefit-cost analysis suggests the strategy can be cost-effective in reducing crashes at stop-controlled intersections, there is a need to analyze potential costs and benefits on a case-by-case basis with site-specific values.

Study Citation: Le. T.Q., F. Gross, and T. Harmon. "Safety Effects of Turning Movement Restrictions at Stop-Controlled Intersections". Presented at the 97th Annual Meeting of the Transportation Research Board, Paper No. 18-03753, Washington, D.C., (2018).


CMFs Associated With This Study

Category: Access management

Countermeasure: Install right-in-right-out (RIRO) operations at stop-controlled intersections

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.55 45 4 Stars All All Not specified Urban
0.32 68 3 Stars Other All Not specified Urban
0.2 80 3 Stars Other K,A,B,C Not specified Urban
1.1 -10 3 Stars All All Not specified Urban
1.02 -2 3 Stars Other All Not specified Urban
0.94 6 2 Stars Other K,A,B,C Not specified Urban
1.64 -64 4 Stars All All Not specified Urban
2.55 -155 3 Stars Other All Not specified Urban
1.56 -56 2 Stars Other K,A,B,C Not specified Urban