The conversion of HOV to HOT lanes on I-394 reduced mainline crashes by 5.3 percent.
Quantiative analysis of pricing on roadway safety
Models were used to estimate traffic with and without the improvement and the Empirical Bayes method was used to determine if crash rates decreased after the conversion. Four-year observations were made before the conversion and two-year observations were made after the conversion.
After the conversion of MnPASS, the analysis indicated that the number of crashes on I-394 decreased by approximately 5.3 percent.
In addition, after the conversion and solo drivers were given a choice to opt in, the violation rate decreased from 20 percent to 9 percent on the concurrent flow section of the I-394 MnPASS whereas the violation rate on the I-35W HOV lanes increased from 23 percent to 33 percent during the same period (Munnich, 2008).
Overall, the safety benefits for the two years following the conversion were estimated at $5 million. The benefits were substantial given that MnPASS collected about $1.2 million in tolls per year.
The authors noted that the specific design of an HOT lane and its layout with other non-HOT lanes can play an important role. Since the I-394 MnPASS HOV-to-HOT lane conversion was accompanied by designating access points, the authors were unable to differentiate the extent of benefits attributable to the pricing component. In addition, since limited studies have been done regarding the safety benefits of HOV-to-HOT lane conversion projects, they were unable to generalize results that would be transferable to other HOT lane sites.
Safety Benefits of Converting HOV Lanes to HOT Lanes: Case Study of I-394 MnPass
Author: Cao, Xinyu (Jason); Zhiyi Xu; and Yan Huang
Published By: 90th Annual Meeting of the Transportation Research Board
Source Date: 23-27 January 2011
Average User Rating
Typical Deployment Locations
high occupancy vehicles, carpool lanes, high occupancy vehicle lane, managed lanes, HOV, congestion pricing, value pricing, variable road pricing