Improved Tabu Search Heuristics for Static Dial-A-Ride Problem: Faster and Better Convergence

Multi-vehicle routing has become increasingly important with the rapid development in autonomous vehicle technology. Dial-a-ride problem, a variant of vehicle routing problem (VRP), deals with the allocation of customer requests to vehicles, scheduling the pick-up and drop-off times and the sequence of serving those requests by ensuring high customer satisfaction with minimized travel cost. In this paper, we propose an improved tabu search (ITS) heuristic for static dial-a-ride problem (DARP) with the objective of obtaining high quality solutions in short time. Two new techniques, construction heuristic and time window adjustment are proposed to achieve faster convergence to global optimum. Various numerical experiments are conducted for the proposed solution methodology using DARP test instances from the literature and the convergence speed up is validated.