Approximating inter-modal travel cost using a hierarchical accumulated cost surface method

Abstract

An essential component of spatial analysis travel is often inter-modal and any surface such as the ground, air or water can be a travel path depending on the travel mode. Current geospatial software, while offering various procedures for complex computation of travel costs based on different factors, can however become quite cumbersome, inflexible and limited in meeting a researcher's needs especially when dealing with inter-modal travel. To more realistically capture this ground truth, simulation models need fast and efficient methods that take into consideration available travel modes rather than simple networks. An innovative approach for computing and visualizing optimal paths in inter-modal travel is proposed in this paper. A modified Accumulated Cost Surface method is used with several travel cost surfaces created based on the underlying topography and available modes of travel. Preliminary tests demonstrated a high level of success in computing travel time on actual road network data. This paper discusses the effectiveness and limitations of this method. Current findings suggest that this method might provide a convenient way for computation and visualization that is suitable for use in Web-based planning support systems.