A practical dynamic share-a-ride problem with speed windows for Tokyo city

This paper deals with a new time-dependent model of public transportation system in the urban context that allows sharing a taxi between a passenger and parcels with speed widows consideration. We solve a realistic dynamic scenario in which requests are accepted or declined at the time of their calls. We classify vehicle speeds by different time windows during a day. Different speed windows induce the dynamic graph model for road networks and make the problem much more difficult to solve. Because of the complex model, the preprocessing steps on data as well as on dynamic graphs are very important. We use a greedy algorithm to initiate the solution and then use some local search techniques to improve the solution quality. The experimental data set is recorded by Tokyo-Musen Taxi company. The data set includes more than 20,000 requests per day, more than 4,500 served taxis per day and more than 130,000 crossing points on the Tokyo map. Experimental results are analyzed on various factors such as the total benefit, the accumulating traveling time during the day, the number of used taxis and the number of shared requests. We expect that our solution has chances to apply directly to real-life situations.