Get In, Get Out, Come Back!: What the Relationship Between Pavement Roughness and Fuel Consumption Means for the Length of the Resurfacing Cycle

Pavement roughness affects the subjective quality of the ride for the traveler and also affects the cost of operating the vehicle. Less frequent resurfacing will reduce the owner agency's maintenance cost and the motorist's delay cost and will increase the motorist's vehicle operating cost. Analysis of a sample of Virginia Department of Transportation pavements indicates that the roughness of a pavement surface deteriorates-that is, increases-by about 1.23 in. per mile per year from the time it is placed until the time it is resurfaced. Recent reports from the WesTrack facility in Nevada, the Florida Department of Transportation, and the National Center for Asphalt Technology pavement test track in Alabama suggest that a gradual increase in roughness will mean a gradual reduction in fuel economy for the vehicles that use the road. Synthesis of these findings makes it possible to compare the maintenance cost to the owner agency against the travel time and operating costs to the motoring public, for maintenance resurfacing cycles of different lengths and for different initial roughnesses. This cost comparison rinds that a decrease in the initial roughness of a new overlay reduces the sum of agency costs and user costs. Although a decrease in initial roughness apparently makes it feasible to prolong the resurfacing cycle, the cycle length that achieves the lowest total annualized cost (resurfacing cost plus delay cost plus fuel expense) remains largely the same: about 10 years. The trade-off between agency costs and user costs that the research findings imply is a caveat to the highway maintenance axiom, "Get in, get out, stay out!".