Performance of reservation-based carpooling services under detour and waiting time restrictions

Abstract This paper examines many-to-many carpooling services with advance reservations, and constraints on waits and detours. An analytic model yields approximate formulas for the percent of requests matched, the expected vehicle-distance driven, and the passenger-distance traveled in some idealized scenarios. Simulations of these scenarios validate the formulas. In the most favorable cases carpooling reduces the vehicle-kilometers driven by all users by a few percent. The paper also shows how the formulas can be used by service providers to optimize offerings, and by city governments to design regulatory policies that will perform as intended. A simple example illustrates the ideas.