In this article, we estimate four general types of external costs for a ton-mile of freight shipped
by truck: accidents (fatalities, injuries, and property damage); emissions (air pollution and
greenhouse gases); noise; and unrecovered costs associated with the provision, operation, and
maintenance of public facilities (primarily roads and bridges). External costs, especially those
related to congestion and air pollution, vary substantially among metropolitan areas. Such costs,
however, are fairly consistent in rural areas. By focusing this analysis on intercity freight move-
ments in rural areas, we avoid the problem of widely varying external costs. Congestion, a pri-
marily urban phenomenon, is therefore not addressed. Our analysis is intended to serve as a
lower-bound benchmark against which area-speci®c external cost estimates can be compared.1