3. Private operating costs
To determine the fractional increase in freight costs that would result if freight trucking were to
pay the full costs it occasions, it is necessary to estimate both the private and external costs of this
transportation mode. Private costs are the direct expenses incurred by providers of freight trans-
portation. Such costs consist of operating costs, as well as investments in capital facilities and
rolling stock which eventually wear out and must be replaced. Operating costs are those that are
closely linked to the amount of service provided: fuel, wages, maintenance, user charges, depre-
ciation, and insurance.