Value of travel time savings incorporating the value of access

Abstract

Value of travel time savings (VTTSs) is widely used in the evaluation of transportation projects. There have been a number of researches regarding the formulation and application of VTTSs. Using empirical data on conserved travel time in Britain, Metz (2008) points out that an improvement in transportation infrastructure does not contribute to the time saving but impacts accessibility. He also shows that the value of access must be considered to evaluate the improvement in transportation infrastructure. This paper examines the meanings of the value of access and proposes the VTTSs incorporating the value of access. This value includes not only the time saved in a given single OD trip but also the changes in the travel patterns of various trips. First, the paper formulates the time allocation model and derives the VTTS from the model. Then, it presents the econometric analysis with the diary activity data collected in Tokyo. Finally, it discusses the implications of the proposed VTTSs on the transportation modeling and policy.