THE SOCIAL COSTS OF INTERCITY TRANSPORTATION - A REVIEW AND COMPARISON OF AIR AND HIGHWAY

This paper provides a comprehensive survey of the literature on the me asures of social costs, providing an indication of the state of engine ering and economic literature. We operationalize the new thinking abou t which externalities to consider in an analysis of the transportation system. We construct measures of each externality: noise, air polluti on, accidents and congestion for the highway and air transportation mo des, where possible as a function of the amount of output or use. rath er than as simple unit costs. We find that noise is the dominant cost of air travel, followed by congestion, air pollution and accidents. Fo r highway travel, accidents are the most significant cost, followed by congestion, noise and air pollution. The social costs of highway trav el are about 15% of the full costs of a highway trip, while the smalle r social costs of air travel are only 5% of the full costs of an air t rip. A highway trip generates four to five times as much externality a s an air trip.