Building Park and Ride (P&R) facilities around the city centre is an interesting policy option to keep automobiles from a city centre, without compromising its accessibility. Car drivers can park at such a Park and Ride location and easily transfer to public transport to continue their journey to the city centre. As cities become more congested, more and more P&R locations are planned. However, it appears to be difficult to predict how many passengers will actually use the facility. A P&R location will only be successful if the multimodal trip (using car and public transport) is more attractive than the 'car-only' trip. Although many current transport models can assign traffic/transport to more then one mode, none of them is capable of dealing with multimodal trips. Therefore Delft UT and TNO have developed a new passenger transport model: TRANSFER, an equilibrium model for analysing multimodal transport systems. Multimodal transport systems are represented using a supernetwork in which several unimodal networks (car, bicycle, bus, tram, metro, train, etc.) are connected by transfer links. The transfer links represent the possibility of making a transfer and the related time and costs. A route in a multimodal network will therefore not only determine which links are used, but also which modes are chosen and - if a transfer is made - the transfer location(s). Of course, TRANSFER will also consider conventional unimodal trips such as car and public transport only. For multimodal transport trips it yields the modes used for access and egress, and the main public transport service. In addition, the locations where passengers transfer from one mode or service to another are incorporated as well. TRANSFER is composed of two major components: a multimodal route-set generation module and an assignment module. First, the route-set generation module will generate a set of (unimodal and multimodal) routes for every origin-destination pair, using a simulation approach based on network attributes and traveller preferences. Next the assignment module will iteratively distribute transport flows among these routes. Because there can be a significant amount of overlap among the routes in the route set, a path-size route-choice algorithm is implemented. Multimodal networks are usually not available. Therefore another tool, called 'Superbuilder', has been developed. Superbuilder combines several unimodal networks and transfer data to automatically generate a multimodal supernetwork containing the characteristics of the unimodal networks and all the relevant transfer possibilities. TRANSFER is an innovative combination of known techniques such as the supernetwork concept (Sheffi, 1985), and newly developed methodologies like multimodal route-set generation (Fiorenzo-Catalano et al., 2004) and Path-Size logit (Hoogendoorn-Lanser et al., 2005). Both the route-set generation and Path-Size logit route choice have never before been applied in a multimodal context. The paper will describe the approach chosen in TRANSFER, using a case-study as an illustration. For the covering abstract please see ITRD E135207.
Abstract