Ferry Service Network Design for Kiel fjord

This paper considers a ferry service network design problem using autonomous ferries for the practical case of the Kiel fjord. Among others, the city of Kiel, Germany, currently runs a number of initiatives for developing an autonomous ferry system to open up new mobility opportunities. The city is divided by the Kiel fjord into an eastern and a western part and the current infrastructure is mainly built to accommodate car transportation on roads around the fjord. We provide a new optimization model for the generation of schedules for an autonomous ferry service, including route design and determination of departure frequencies. The model captures practically relevant aspects of minimum required departure frequencies between specific port pairs and understandable ferry schedules, whilst maximizing customer service quality (i.e., excess transit times and departure frequencies). We provide a two-step optimization approach where candidate combinations of routes and departure frequencies are heuristically generated a priori and fed into an integer programming model. Experiments on real world data provide managerial insights in regard to ferry fleet size, port network design and ferry schedules.