Research on the Fleet Size of Shared Autonomous Vehicles in the Future City: An Example in Shanghai

The development of autonomous driving technology makes it possible to replace traditional vehicles with shared autonomous vehicles (SAV) in the future. The SAV’s fleet size problem is studied in the case of using SAV to meet all motorized travel demands. The cell phone signaling data of 3 million users in Shanghai is used to extract motorized travel demands. The impact of actual road conditions is considered. A graph theory model based on the vehicle-sharing network is established to convert the minimum fleet size problem into the minimum path cover problem of directed acyclic graphs, which is solved by the Hopcroft-Karp algorithm. To meet motorized travel demands of 3 million cell phone users, 128,000 SAVs are needed. The impact of the maximum scheduling time limit and traffic congestion are also studied. The study provides a reference for determining the fleet size of SAVs and corresponding infrastructure planning at the city level.