Design of multimodal transport networks, a hierarchical approach

Design of multimodal transport networks, a hierarchical approach Rob van Nes, 25 September 2002 Multimodal transport relates to trips for which travellers use two or more transport modes, for example bicycle and train, train and bus, or private car and metro. The requirements for multimodal transport are numerous: transfer nodes, travel information, synchronised transport services, and so on. One of the questions is whether multimodal transport requires a new approach to transport network design. This question is the topic of this study. The main theme in this dissertation is the notion of hierarchical networks. Multimodal transport usually implies that one transport mode is used for actually making the trip, while the other modes are used as access or egress modes. The transport modes, and thus also the related transport networks, operate together in a hierarchical structure. It is easy to distinguish such hierarchical structures in existing networks, for instance, regional roads and freeways, or short-distance and long-distance public transport services. Analytical network design models are used to determine the main factors that influence hierarchical network structures. The theory for transport network design has been extended to multi-level hierarchical transport networks. The description of travel behaviour has been improved by including route choice in hierarchical transport networks and by including access mode choice. Furthermore, game theory has been used to model relationships between network levels. In all analyses a consistent framework has been used in which the interests of the travellers are balanced by the costs of the related transport networks. The main conclusion of this study is that the notion of multimodal transport does not require a new approach for transport networks design. For road networks mechanisms have been found that lead to a stable pattern of network levels. For public transport service networks the hierarchy in settlements proves to be decisive for network hierarchy. Transport networks that are structured according to these principles are optimal for unimodal trips as well as multimodal trips.