THE USE OF COWAN'S M3 HEADWAY DISTRIBUTION FOR MODELLING URBAN TRAFFIC FLOW

Cowan's M3 headway distribution model uses a dichrotomised function to model vehicles as either tracking at a given headway or travelling free. Methods for determining parameters for Cowan's M3 headway model are presented. These are: a) the Method of Moments; and b) Maximum Likelihood Techniques. A comparison of the methods is made. The application of the model in the design of roundabouts and unsignalised intersections is discussed briefly. This paper also compares Cowan's model with the Double Displaced Negative Exponential Distribution (DDNED) model.