An accuracy check of trip survey data was conducted to estimate the daily vehicle-miles of travel (dvmt) in the metropolitan areas of chicago and pittsburgh. The average daily traffic count on both arterial and local streets generally decreased with increased distance from the central business district (cbd) although arterial counts in the cbds themselves were lower than in the first several analysis rings. The progressive decrease was smoother for local streets, the arterial counts tending toward a plateau in the first several analysis rings. The peak hour percents on both arterial and local streets generally increased with increase distance from the cbd and with decreased traffic counts. Existing traffic counts were not a specific criteria for street classification, but it was found in chicago that an average daily traffic count of 3,000 vehicles had been used as the dividing line between an arterial and local classification. Much the same street systems would have been designated except in the outer analysis rings. The estimation of dvmt in the metropolitan area is a relatively easy procedure requiring only traffic counts and street mileage measurements. The results of such estimation are valuable as an accuracy check of origin-destination study trip data.
Abstract