Should autonomous shared taxis replace buses? A simulation study

The introduction of shared autonomous vehicles (SAV) will likely reduce operation cost per vehicle and might thereby allow to enhance conventional public transit systems with numerous small SAVs offering flexible ridesharing-like feeder services. These demand-responsive services could replace conventional bus lines limited by their fixed routes and their fixed schedules. This simulation study explores the potential of replacing conventional bus lines with shared autonomous vehicles in a suburban area of Berlin. Several scenarios with different fleet sizes and vehicle sizes are simulated using the multi agent transport simulation MAT-Sim. The simulation suggests for all evaluated scenarios higher operating costs and only slight travel time savings in comparison to conventional buses. Door-to-door service allows for significant reductions in average walk time, but causes numerous detours which consume a high share of the time gained. A fleet of 150 SAVs with 4 seats each seemed appropriate for the simulated area with approximately 24 000 inhabitants.