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 spending in a given year reduces the congestion costs to road users only eleven cents in that year. We also find that even if the allocation of spending were optimized to minimize congestion costs that it still is not a cost-effective way to reduce congestion. We conclude the evidence strengthens the case for road pricing.