Mobility Sharing as a Preference Matching Problem

Abstract

Traffic congestion, dominated by single-occupancy vehicles, reflects not only transportation system inefficiency and negative externalities but also a sociological state of human isolation. Advances in information and communication technology are enabling the growth of real-time ridesharing to improve system efficiency. While most ridesharing algorithms optimize fellow passenger matching based on efficiency criteria (maximum number of paired trips, minimum total vehicle-time, or vehicle-distance traveled), very few explicitly consider passengers’ preference for their peers as the matching objective. The existing literature either considers the bipartite driver–passenger matching problem, which is structurally different from the monopartite passenger–passenger matching, or only considers the passenger–passenger problem in a simplified one-origin–multiple-destination setting. We formulate a general monopartite passenger matching model in a road network and illustrate the model by pairing 301 430 taxi trips in Manhattan in two scenarios: one considering 1000 randomly generated preference orders and the other considering four sets of group-based preference orders. In both scenarios, compared with efficiency-based matching models, preference-based matching improves the average ranking of paired fellow passenger to the near-top position of people’s preference orders with only a small efficiency loss at the individual level and a moderate loss at the aggregate level. The near-top-ranking results fall in a narrow range even with the random variance of passenger preference as inputs.