This paper describes a simulation model of bus priority developed at the University of Bradford, England. Two digital computer simulation models were developed to aid in determining the overall travel effects of bus priority. Observations of traffic flow on the highway were carried out to determine the characteristics of speed and headway distributions. A microscopic Monte Carlo simulation model was used that assigned each vehicle entering the section of the highway under study to a lane and to a vehicle type. A comparison was made between the travel times of buses and non bus vehicles by running the priority and nonpriority models under identical traffic flows and signal settings. The study concluded that the use of these two speed and flow relationships allowed overall passenger travel time savings to be calculated for various proportions of buses in the traffic flow. Since the introduction of the bus-priority scheme, field observations have verified the validity of the model.