Transfer Graph Approach for Multimodal Transport Problems

Abstract

Route guidance solutions used to be applied to single transportation mode. The new trend today is to find route guidance approaches able to propose routes which may involve multi transportation modes. Such route guidance solutions are said to be multi modal. This document presents our contribution to multimodal route guidance problem. Following our strategy, we introduce a new graph structure to abstract multimodal networks. The graph structure is called transfer graph. A transfer graph is described by a set of (sub) graphs called components. They are connected via transfer points. By transfer point we mean any node common to two distinct components of a transfer graph. So a transfer graph is distinct from a partitioned graph. An example of transfer graph is a multimodal network in which all participating unimodal networks are not merged, but are kept separated instead. Since a multimodal network is reducible to a transfer graph, transfer graph based approach can be used for multimodal route guidance. Finally, to give meaning to our work, we try to insert our approach with the shortest path service in Carlink project. This step is seen as the implimentation of our algorithm, so we can get an idea on its performance.