Ride Sharing in Personal Rapid Transit Capacity Planning

Personal Rapid Transit (PRT) systems are designed so that passengers usually travel together only by choice, but strangers may choose to share a vehicle at peak times, when the system is near capacity. By predicting whether and to what extent this ride sharing will occur, PRT planners can better estimate the impact on system capacity and passenger experience. This paper develops a model for ride sharing based on queueing theory and applies it to explain the relationships between vehicle occupancy, passenger queue length and passenger waiting time. The effects of multiple destinations, passengers who are unwilling to share and passengers arriving in preformed parties are considered. A case study is provided to show how the model can be applied to a simple point-to-point system; in this case study it appears possible to reduce the size of the vehicle fleet by at least 30%, while still maintaining a high level of service for passengers during peak times.