A network model of urban taxi services

A network model is developed to describe how vacant and occupied taxis will cruise in a road network to search for customers and provide transportation services. The model can determine a number of system performance measures at equilibrium, such as vacant taxi movements and taxi utilization for a given road network and the customer origin–destination demand pattern. The effects of the taxi fleet size and the uncertainty on the system performances are explicitly taken into account. The model offers some interesting insights into the nature of the equilibrium of taxi services, and offers some policy-relevant results for decision making. These include the findings that the average taxi utilization decreases sharply with the number of taxis operating, and that the higher the taxi utilization, the larger the average customer waiting time.