Title

Doubling Personal Rapid Transit Capacity with Ridesharing

Document Type

Journal Article

Publication Date

2005

Subject Area

operations - capacity, infrastructure - vehicle

Keywords

Waiting time, Vehicle occupancy, Transit capacity, Simulation, Security measures, Security, Ridesharing, Regulatory policy, PRT, Policy, Policies, Personal rapid transit, Peak periods, Government policy, Computer simulation

Abstract

A new personal rapid transit (PRT) operating policy is specified; it can often double peak period capacity with moderate wait times. When a passenger selects a destination for a vehicle, the destination is displayed for all to see. Any waiting passenger going to the same destination can also board. However, vehicles are not delayed just to gather additional riders. Fares are charged per person, rather than per vehicle. If the passenger queue length happens to equal the number of destinations and all destinations are equally likely, it is shown that on average one extra passenger will board each vehicle and that vehicle occupancy and line capacity will approximately double. The average wait time in this case will be approximately N/(2R), where N is the number of destinations and R is the vehicle arrival rate at the origin station. A station layout that facilitates this ridesharing policy is presented, and security measures are described for strangers traveling together. Simulation results give occupancy values up to 18% higher than expected from a simple model. During peak periods with directional flows, passengers facing a long wait can choose to travel to a destination near their own with no passenger queue and from there immediately board a vehicle to continue to their original destination. This makes ridesharing feasible in relatively large PRT systems.