In the face of rising congestion on the nation's road system, policymakers have explored ways to reduce travel delays. One approach has been to allocate reserved lanes - called high-occupancy-vehicle (HOV) lanes - to vehicles carrying two or more people. A recent innovation is to allow solo...

Policymakers attempt to reduce the growth of congestion by spending billions of dollars annually on our road system. We evaluate this policy by estimating the determinants of congestion costs for motorists, trucking operations, and shipping firms. We find that, on average, one dollar of highway...