Shared Mobility

This paper presents a preliminary study of the feasibility of checkpoint dial-a-ride systems. Their cost-effectiveness is compared to that of fixed route systems with no transfers and door-to-door dial-a-ride systems. The results are derived for a simple routing strategy, and involve some simplifications which facilitate the comparisons. For high demand levels, the total cost per passenger for fixed route and checkpoint systems is very close. In fact, their optimal configurations are so alike, and the occurrence of route deviations is so rare, that fixed route systems should be preferred,...

The paper presents a general analytic framework to model transit systems that provide door-to-door service. The model includes as special cases non-shared taxi and demand responsive transportation (DRT). In the latter we include both, paratransit services such as dial-a-ride (DAR), and the form of ridesharing (shared taxi) currently being used by crowd-sourced taxi companies like Lyft and Uber. The framework yields somewhat optimistic results because, among other things, it is deterministic and does not track vehicles across space. By virtue of its simplicity, however, the framework yields...

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...

On-demand traffic fleet optimization requires operating Mobility as a Service (MaaS) companies such as Uber, Lyft to locally match the offer of available vehicles with their expected number of requests referred to as demand (as well as to take into account other constraints such as driver’s schedules and preferences). In the present article, we show that this problem can be encoded into a Constrained Integer Quadratic Program (CIQP) with block independent constraints that can then be relaxed in the form of a convex optimization program. We leverage this particular structure to yield a...