Predicting Arrival Flow Profiles and Platoon Dispersion for Urban Street Segments

Abstract

This paper describes the development of a procedure for predicting the arrival flow profile for an intersection approach. This profile describes the variation in flow rate during the average signal cycle as it would be measured at a specified point downstream of a signalized intersection. Research indicates that platoon decay (due to midsegment driveway access and egress) tends to have a more significant impact on the arrival flow profile than platoon dispersion. Platoon dispersion reflects drivers' desire to increase their headway, while platoon decay reflects vehicles departing the platoon at midsegment access points. The procedure is recommended for inclusion in the Urban Street Segments chapter of the forthcoming 2010 Highway Capacity Manual.