Hetereogenous travel activity patterns in Japan: Accounting for inter-dependencies in mobility tool use

Abstract

Using data from the Japanese 5 th nationwide person trip survey, a joint model of trip frequencies by mode (car, transit and non-motorized) is estimated using a generalized heterogeneous data model to account for inter-dependencies stemming from unobserved factors. The estimated model successfully captures the effect of common unobserved factors on trip frequencies by mode underscoring the need to account for modal inter-dependencies to avoid bias in parameter estimates. Consistent with findings from the literature, results suggest the existence of substantial mode substitution effects between car and transit and non-motorized modes given changes in accessibility levels. Furthermore, given common unobserved factors, statistically significant and substantial substitution effects were observed among all modes.