This paper presents the findings of a study dealing with the relationship between truck operating costs and pavement roughness. The cost components considered were the cost of parts and labor for repairs and maintenance and the cost of tires. Repair and maintenance cost data was collected from a number of trucking companies operating on dedicated routes. Tire cost data was obtained from Goodyear’s test truck fleet for trucks that operated on dedicated routes. The relationships developed show a significant effect of pavement roughness on these truck operating cost components.