Self-organized ridesharing: Multiperspective annotated review

Most cars traversing the roads for commuting purposes travel as single-occupant vehicles, generating externalities in the form of congestion, pollution, and vehicle-miles traveled. A relatively efficient and sustainable transportation option for addressing these concerns is ridesharing—the practice of sharing a car with other passengers, free-of-charge, or expense sharing. The history of ridesharing spans more than a century and includes different initiatives, some offered by official authorities and some arising from spontaneous bottom-up self-organization. This article presents a qualitative multidata-source review aimed at exploring the knowledge base of self-organized ridesharing. The review reveals that: (1) the literature mainly treats self-emergent ridesharing as separate occurrences; (2) these cases have repeated forms, attributes, and influencing factors; (3) practice theory combined with additional framing theories, mainly grassroots innovation (GI), multilevel perspective (MLP), and sharing economy (SE), have the potential to collectively explain some of these cases; and (4) emergence processes and local context hold the key to the success of these cases, yet this is seldom captured in research. The review offers insights into existing self-emerging cases and demonstrates the applicability of findings in analyzing a particular case. It identifies future work required to establish repeated patterns, or a meta-type, capturing self-organized ridesharing.