Abstract
An approach to the formulation of speed distribution model for traffic flow is investigated. Considering the proportion of leader and follower cars, the elementary model of speed distribution for the ideal uniform traffic flow is proposed. Then, a model of actual speed distribution in a given period is formulated by assembling elementary models, which can reflect the pattern of fluctuation of 1-minute traffic volume and the presence of congested flow. It is found that the data observed at arterial two-lane roads and our proposed elementary and actual models for speed distribution are matched properly. Some of the speed distribution characteristics are also illustrated.
