COMPARISON OF MEASURED AND FORECAST TRAFFIC VOLUMES ON URBAN INTERSTATE HIGHWAYS.

FORECASTS OF 1975 AVERAGE DAILY TRAFFIC (ADT) ON 78 INTERSTATE HIGHWAY SEGMENTS WERE COMPARED WITH MEASUREMENTS OF 1975 ADT ON THE SAME SEGMENTS. THE FORECASTS WERE MADE IN 1968 AND 1972. IT WAS FOUND THAT THE 1968 AND 1972 FORECASTS TENDED TO OVER-ESTIMATE 1975 ADT BY 24 AND 21% RESPECTIVELY. POSSIBLE SOURCES OF THIS FORECASTING BIAS INCLUDE THE RESIDUAL EFFECTS OF THE 1973-74 GASOLINE SHORTAGE AND ERRORS IN TRAFFIC ASSIGNMENT TECHNIQUES.(Author/publisher).