Patient Transportation – Dynamic Dial-a-Ride and Emergency Transportation Problems.

Günter Kiechle, Karl Dörner, Michel Gendreau, Richard Hartl (2007): Patient Transportation – Dynamic Dial-a-Ride and Emergency Transportation Problems. In: Preprints of Triennial Symposium on Transportation Analysis (TRISTAN) 2007

In Austria, the transportation of patients to and from hospitals is organized by non-profit organizations. In most regions, it is the Austrian Red Cross that is responsible for the transportation of patients. The regular patient transportation, as well as the emergency transportation, are performed by scheduling the same fleet within the same control center.

Therefore a dial-a-ride problem for the regular patient transportation orders with disruption has to be solved. Disruptions occur due to the fact that vehicles “disappear” in order to serve emergency requests and reappear at a hospital after the service of an emergency case. This problem is highly dynamic and a robust plan has to be computed for the regular dial-a-ride orders in order to serve also the emergency requests. When a disruption occurs because of an emergency, the fleet size is reduced and the remaining patient transport orders have to be carried out with this reduced fleet size. After the execution of an emergency transport, the available vehicle can be integrated to serve the regular dial-a-ride orders.

We analyze different scheduling strategies for the regular dial-a-ride orders in order to minimize routing costs and to minimize the response time for servicing an emergency request.