Analyzing the benefits of an integrated mobility system using a matheuristic routing algorithm

In many Western countries, governments are currently implementing an innovative demand-driven mobility policy. Providers of collective door-to-door transport, called dial-a-ride services, are increasingly invoked to replace unprofitable public transport in rural areas. This requires an integrated mobility system in which a user’s trip may consist of a combination of dial-a-ride services and regular public transport. In order to optimally integrate both systems from an operational point of view, dial-a-ride providers need to solve a challenging routing problem. Their flexible vehicle routes should be synchronized to the timetables of the remaining public transport services, while the optimal selection of the users’ transfer terminals depends on the actual structure of the dial-a-ride routes. This paper introduces a routing algorithm and integrated scheduling procedure to enforce this synchronization for problems of a realistic scale, enabling the design and operational implementation of an integrated mobility system. Experiments, performed on a new artificial benchmark data set with realistic characteristics, clearly indicate that from the perspective of the dial-a-ride providers, considerable operational benefits can be obtained by integrating public transport into their services. The resulting distance savings for the dial-a-ride vehicles are shown to depend on the operational characteristics of the system, the geographical distribution of the demand, and the ability to flexibly assign transfer terminals to user requests. Furthermore, the proposed algorithm is also very efficient in solving related problems in passenger and freight transport.