Study Details

Study Title: Impact of Truck Lane Restrictions on Four-Lane Freeways in Mountainous Areas

Authors: Fontaine

Publication Date: JAN, 2008

Abstract: A number of states have implemented truck lane restrictions in an attempt to improve safety and mobility on freeways. These restrictions have typically prohibited trucks from traveling in the median lane of freeways that have more than 3 lanes per direction. Virginia has recently implemented a new type of truck restriction which prohibits trucks traveling more than 15 mph below the posted speed limit from the left lane on four-lane interstate segments. This new restriction is primarily used in mountainous areas of the state where truck climbing lanes may be warranted but are not present. This paper documents the results of a safety and operational evaluation of these truck lane restrictions. Crash data were examined at 19 sites with restrictions. Likewise, operational data were collected at 4 sites with restrictions to assess compliance and the extent to which slowmoving trucks were impeding traffic flow. The safety analysis shows some positive trends in crash rates following implementation of the restrictions, but only the overall number of fatal and injury crashes showed a statistically significant decline. While compliance with the restrictions was generally good, a number of slow moving vehicles, including passenger cars, were still found to be impeding traffic in the left lane.

Study Citation: Fontaine, M.D. "Impact of Truck Lane Restrictions on Four-Lane Freeways in Mountainous Areas." TRB 87th Annual Meeting Compendium of Papers CD-ROM. Washington, D.C., 2008.


CMFs Associated With This Study

Category: Roadway

Countermeasure: Implement truck lane restrictions on 4-lane freeways

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.89 11 2 Stars All All Principal Arterial Other Freeways and Expressways
0.68 32 3 Stars All K,A,B,C Principal Arterial Other Freeways and Expressways

Countermeasure: Implement truck lane restrictions on 4-lane freeways (truck crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.12 -12 2 Stars All All Principal Arterial Other Freeways and Expressways
0.73 27 2 Stars All K,A,B,C Principal Arterial Other Freeways and Expressways