Per Mile Costs of Operating Automobiles and Trucks

A methodology and simple model for use in benefit-cost analysis of highway projects are described for calculating the variable per mile costs of operating cars and trucks. Although the marginal vehicle operating costs generated by changes to trip mileage or operating conditions are typically a small part of total project costs, they can be significant in deciding among alternative designs, construction scenarios, or project timing. Operating costs for personal vehicles (autos, pickups, SUVs, vans) are developed primarily from consumer guides, with an overall fleet average cost based on vehicle sales. Operating costs for large commercial trucks are based on a review of a number of sources of trucking costs. Factors for adjusting the costs based on stop-start conditions, pavement roughness, and inflation are derived from various sources. Results are that in a "baseline" case of highway driving on smooth pavement, with a fuel price of $1.50 per gallon and other costs in 2003 dollars, personal vehicles average 17.1 cents per mile to operate and trucks average 43.4 cents per mile, not counting costs associated with the driver or travel time. City driving conditions, involving frequent stops and starts, increase this cost by 3.9 cents per mile for personal vehicles and 9.5 cents for trucks. Extremely rough pavement increases the baseline cost by 2.7 cents for personal vehicles and 5.5 cents for trucks.