Simulation of mixed traffic flow on four-lane divided highways

Abstract

This paper presents a complete methodology for analyzing mixed traffic on four-lane divided highways in India. An appropriate parameter for defining vehicle arrival patterns is found to be Coefficient of Variation (COV). The speed distributions are successfully defined by the concept of unimodal and bimodal distributions. Speed Dispersion Ratio (SDR) is a new parameter, which is introduced to quantify the effects of vehicular interactions in a mixed traffic stream on the speed distribution curves. Showing a significant influence on lane-usage, placement behaviour, and acceleration behavior of vehicles is the factor of shoulder conditions. In order to determine the capacity of four-lane divided highways for homogeneous types of traffic and for two vehicle categories at a time, a simulation program is also developed and runs were performed. Also estimated are Passenger Car Unit (PCU) values, and in order to determine the capacity of traffic mix for different shoulder conditions, a general equation is proposed. The effect on capacity and stream speed of traffic mix is discussed, in addition.