Study Details

Study Title: Safety Benefits of Converting HOV lanes to HOT lanes: Case Study of the I-394 MnPass

Authors: Cao et al.

Publication Date: 2011

Abstract: Recently the conversion of high-occupancy-vehicle (HOV) lanes to high-occupancy-toll (HOT) lanes has been increasingly popular in the U.S. Several empirical studies have explored the benefits and costs associated with the conversion. However, few quantitative studies have been performed to examine the impact of HOV-to-HOT conversion on traffic safety. Applying the Empirical Bayes method, this paper investigated the crashes on the I-394 MnPass lane before and after its conversion, controlling for the length of highway segments and AADT. We found that total crashes were reduced by 5.3% after the conversion. The benefits were practically important when compared to the tolls collected. We also compared Empirical Bayes approaches with other simple before-after approaches, and we found that other approaches tend to overstate the safety benefits of the HOV-to-HOT conversion.

Study Citation: Cao, X., Xu, Z., and Huang, Y., "Safety Benefits of Converting HOV lanes to HOT lanes: Case Study of the I-394 MnPass." TRB 90th Annual Meeting Compendium of Papers. Washington, D.C., (2011). Also published in: Cao, X., Xu, Z., and Huang, Y., "Safety Benefits of Converting HOV lanes to HOT lanes: Case Study of the I-394 MnPass." ITE Journal, Vol. 82, No. 2, Washington, D.C., (2012) pp. 32-37.


CMFs Associated With This Study

Category: Roadway

Countermeasure: Convert High-Occupancy-Vehicle (HOV) lanes to High-Occupancy-Toll (HOT) lanes

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.95 5 3 Stars All All Principal Arterial Interstate Urban
0 100 2 Stars All K Principal Arterial Interstate Urban
0.39 61 2 Stars All A Principal Arterial Interstate Urban
1.06 -6 3 Stars All B Principal Arterial Interstate Urban
0.96 4 3 Stars All C Principal Arterial Interstate Urban
0.89 11 3 Stars All O Principal Arterial Interstate Urban