Analyzing Dial-a-Ride systems in Austrian rural regions

The Dial-a-Ride Problem (DARP) asks for a minimal cost schedule for a set of customer requests served by a fleet of vehicles. Further restrictions, like time windows, pick-up and drop-off locations and capacity constraints are generally customary. A common example arises in passenger transportation, especially for elderly people or people with impaired mobility. In this work, we consider two different DARP systems employed by Austrian mobility providers. Both operators focus on rural regions and make use of a heterogeneous fleet of vehicles. Additional characteristics are for example the transportation of people with impaired mobility or break times for drivers. We consider two different optimization approaches, namely a Mixed-Integer Linear Programming approach and Large Neighbourhood Search. In a computational study, we show different operator scenarios, like minimizing overall driven kilometres, number of used vehicles or the number of unscheduled requests, for up to 500 requests per day and 30 vehicles.