Variants of the Dial-a-Ride Problem encountered by Austrian mobility ...

The Dial-a-Ride Problem (DARP) consists of defining a set of routes that satisfy transportation requests. A request consists of a pick-up location, where one or many passengers get on the vehicle, a drop-off location, and further restrictions, namely time windows and capacity constraints. A common example arises in door-to-door transportation of people and in our work, we focus on elderly people or people with impaired mobility. We consider a dynamic-deterministic variant of the DARP for two Austrian mobility providers. The focus of these operators lies on rural regions served by a heterogeneous fleet of vehicles and as an additional condition, we take the capacity of wheelchairs into account. We consider a heuristic and an exact solution approach for the DARP, namely a Large Neighbourhood Search and a Mixed-Integer Linear Programming approach. In a computational study, we show different operator scenarios, including minimization of overall driven kilometres, number of used vehicles, and number of unscheduled requests, with up to 500 requests per day and 30 vehicles.