EFFECTS OF PROGRESSION QUALITY AND TRAFFIC FLOW NON-STATIONARITY IN DELAYS MODELS AT SIGNALIZED INTERSECTIONS. HIGHWAY CAPACITY AND LEVEL OF SERVICE. PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY, KARLSRUHE, GERMANY, 24-27 JULY 1991

To allow for the effect of platooned vehicle arrivals on delays at signalized intersections, the 1985 Highway Capacity Manual (HCM-85) uses progression factors. Results of empirical validation studies of the HCM-85 delay model have shown that the modified model is more accurate and its calibration gave an expression similar to one presented in the NCHRP report. Based on results of simulation studies of the effects of non-stationary flow demands on traffic conditions, a modified form of Akcelik's delay expression is suggested.