National Center for Sustainable Transportation

Traffic congestion causes significant economic costs, wasted time, and public health risks. Ride-sharing, defined as a joint trip of more than two participants who share a vehicle that requires coordination among itineraries, has the potential to help mitigate congestion. A good ride-sharing system should provide quick response to passenger requests while identifying routes with minimum travel time. This is not an easy task, especially with dynamic passenger requests, variable request times, and cancelations of existing requests. One way to mitigate the effect of these uncertainties is to allow passengers to walk to a designated pick-up spot while waiting for the drivers, which can improve the system’s efficiency. Taking advantage of ride-sharing incentives such as High Occupancy Vehicle (HOV) lanes can also reduce travel time and make ride-sharing more appealing. Researchers at the University of Southern California developed a two-stage algorithm to solve the routing problem in real-time within a context where ride-sharing drivers are traveling toward their own destinations while making detours to serve passengers with flexible pickup and drop-off locations. The researchers also simulated operation of a ride-sharing system with and without HOV lanes and passenger meeting points, to determine the impact of these two factors on the operation of the system. This research brief summarizes the findings from that research and provides research implications.

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