On Optimizing Shared-ride Mobility Services with Walking Legs

TL;DR

This review paper examines shared-ride mobility services with walking legs, highlighting their operational benefits, challenges, and potential for reducing vehicle travel and improving service efficiency, while identifying key research gaps.

Contribution

It provides a comprehensive review of SRSWL, classifies configurations, analyzes operational challenges, and discusses future research directions in optimizing these services.

Findings

SRSWL can reduce vehicle kilometers and improve efficiency.

Operational subproblems include pickup/drop-off and waiting strategies.

Future research should address modeling challenges and customer service quality.

Abstract

Shared-ride mobility services that incorporate traveler walking legs aim to reduce vehicle-kilometers-travelled (VKT), vehicle-hours-travelled (VHT), request rejections, fleet size, or some combination of these factors, compared to door-to-door (D2D) shared-ride services. This paper provides a review of shared-ride services with walking legs (SRSWL), particularly the studies in the literature that model the operational problem(s) associated with SRSWL. The paper describes the operational and societal benefits of SRSWL as well as compares the SRSWL to circuitous D2D shared-ride services, ride-hailing services, and fixed-route transit services, in terms of VKT and traveler walking distance. The paper then delineates the operational subproblems associated with the SRSWL and discusses their computational complexity. Additionally, the review classifies configurations of SRSWL based on flexibility in assigning travelers to pickup and drop-off locations. The paper also discusses four modelling challenge: short-distance person trips, drop-off location choice for a vehicle's last remaining passenger, allowing vehicles to wait for travelers at pickup locations, and simultaneously reducing VHT/VKT and improving customer service quality relative to D2D shared-ride services. The review paper concludes by discussing the most critical areas of future research related to SRSWL.