UC Irvine Institute of Transportation Studies

In this paper, we investigate the complementary question of the optimal durability of highways. We find that in order to minimize discounted lifetime costs, typical urban interstate highways should be designed with thicker pavements lasting much longer between repavings. Furthermore, although existing roads have marginal pavement-wear costs that are quite high, optimal high-volume urban interstates would not. Thus the need for marginal-cost taxation, and the accompanying diversion of trucking industry revenues, would be virtually eliminated on a large portion of the nation's highway network if the highways were built to optimal standards. 

We begin by reformulating the standard model of optimal highway pricing and investment (see Winston, 1985, p. 78) to include highway durability as a long-run decision variable. The resulting pricing rule includes both a congestion charge related to scarce capacity, and a heavy-vehicle charge related to scarce durability. We derive expressions for marginal-cost user charges, optimal capacity, optimal durability, and long-run marginal pavement-wear cost. We then explore empirically those parts of the model related to durability.