From Ride-Sourcing to Ride-Sharing through Hot-Spots

Smartphones have allowed us to make ad-hoc travel arrangements. Ride-sharing is emerging as one of the new types of transportation enabled by smartphone revolution. Ride-sharing aims to alleviate current environmental, social and economical issues many big cities are facing due to low vehicle occupancy rates. Although ride-sharing companies have millions of users around the world, some of them do not offer true ride-sharing but a similar service called ride-sourcing where private car owners provide for-hire rides. Ride-sharing uptake has not been wide due to lack of convenience and incentives. We propose an enhanced ride-sharing model through the inclusion of proper places to meet that we call hot-spots. Hot-spots are shown to increase the convenience by solving the round-trip ride-sharing problem. As we represent our enhanced model through graphs, we introduce a new graph problem that we call Constrained Variable Steiner Tree, which is NP-hard. An effective and readily deployable heuristic solution to this problem is presented which is up to two orders of magnitude faster than the state-of-the-art solution as combinatorial explosion is avoided by the usage of a novel monotonic nondecreasing function.