Underride safety protection: benefit-cost assessment of rear-impact guards for the North Dakota farm truck fleet.

OBJECTIVE The North Dakota Legislature recently passed a law exempting the state's agricultural truck fleet from a federal safety program requirement for rear-guard equipment on large trucks. This equipment has been shown to reduce crash severity when a passenger vehicle collides with the rear of the truck. This study uses truck fleet, truck crash, and injury severity data to estimate the public safety benefit derived from passenger-vehicle underride protection during rear-end crashes involving large agricultural trucks in North Dakota. METHODS A benefit-cost analysis of crash injury avoidance is developed based on the frequency and severity of rear-end truck collisions in North Dakota between 2001 and 2007. RESULTS The injury avoidance benefits and commercial vehicle safety grant benefits are estimated to be $11.4 to $20.2 million during the seven-year depreciable truck life. CONCLUSION The public safety benefits for rear-impact guards are higher than the estimated lifetime cost for the equipment and maintenance of $8.1 million.