On the use of annual vehicle miles of travel estimates from vehicle owners

Abstract Estimates of annual vehicle miles of travel from 433 vehicle owners are compared with “actual” annual mileages as obtained from odometer readings recorded as part of North Carolina's Motor Vehicle Inspection Program. The results show that owners tend to overestimate annual mileage on low-usage vehicles and underestimate annual mileage on high-usage vehicles. On the average, the owners' estimate did not differ significantly from the actual mileage. A single estimate of annual vehicle miles of travel is not reliable, as errors of estimation are large. However, the distribution of errors is approximately normal and centered near zero. Hence, the mean annual miles may be estimated with any desired precision by including more owners in the sample.