Estimation of Travel Times in the Context of Intermodal Transportation

摘要

Travel-time is recognized as a critical ingredient in assessing the service f.actor of transportation.Two approaches to estimation of travel time using geographical information systems(GIS)-rastercalculator(Euclidean distance algorithm or cost distance algorithm) and network analysis-are described.After analyzing the travel-time components and tendency of modern transport systems,it is suggested that travel time for a specific journey is uncertainly and transportation changes the relationship between space and time with the emergence of intermodal transport.Focusing on the estimation of travel time in the context of intermodal transport,a hybrid model combining raster calculator and network analysis is proposed in this paper for calculating the travel times between origin point and the whole space.In this proposed model,the travel-time components may include an initial walk time from origin point to public transport stop,transport time between the same or different transportation network modes,and a final walk time from public transport stop to destination point.The uncertainly part in travel-time components,such as the time of travel(whether of departure or arrival),transport congestion,and the time for transmodes can be solved by network setting.This paper integrates the model into a GIS environment for regional planning,which successfully copes with the complexity of the public transport of a large region.Finally,this paper explains the result of different method.