Abstract: Assuming the vehicle speed follows a truncated normal distribution ranging from a minimum speed to a free flow speed, the dispersion characteristics of queuing platoon as it moves down from the upstream intersection were analyzed from the aspect of traffic flow density. The piecewise calculation formulas of the traffic flow density function of the platoon at temporal-spatial coordinates were derived. The calculation formulas were derived for the numbers of vehicles of the platoon having passed and not passed a downstream section, and the traffic flow distribution modes at upstream and downstream sections were obtained. A platoon density dispession model was established. The dispession models at the front and rear of the platoon were also derived to facilitate the coordination in a traffic signal control system. Taking the numerical calculation about the coordinate control of signals in the successive intersections as an example, the proposed model was validated.

Key words: engineering of communications and transportation system, platoon density dispersion model, truncated normal distribution, signal coordination control