Value of travel time savings of urban private travel: Comparison of Tokyo and Karlsruhe

Abstract

This paper formulates a time allocation model and estimates empirically the value of travel time saving (VTTS) with the model. First, the paper will formulate an individual's time and cost allocation for a week with three types of discretionary activities, after-work leisure activity, out-of-home leisure activity and in-home leisure activity. The model has the nested structure consisting of the following two models: one-day model and weekly model. The expected optimal duration and expenditure estimated from the one-day model will be used in the parameter estimation of the weekly model. Next, the paper will apply the model to two activity diary surveys collected in the cities of Tokyo, Japan and Karlsruhe, Germany. Then, the paper determines the VTTSs of two cities with the estimated parameters. The empirical analysis shows that both the means and the modes of the simulated VTTSs for after-work leisure on a work day are higher than those for out-of-home leisure on a non-work day. As the variance of the simulated VTTSs in Tokyo is larger than that in Karlsruhe, the average VTTSs is also larger in Tokyo than those in Karlsruhe.