Urban expansion and travel behavior evolution in Shenzhen: the role of travel time budget

The impact of the built environment on travel behavior has received extensive research attention around the world over the past decades. Different study designs and various sophisticated modeling approaches have been used to estimate the impact. However, most of the existing studies assume that the impact of the built environment on travel behavior is time-invariant, ignoring the fact that such impact may change over time especially over the course of urban expansion. Recognizing these long-term trends are crucial to accurately evaluate the influence of land use policies on transport demand. Further, there is a long-time debate on the existence of a stable time budget that people are willing to spend on daily travel. Urban expansion may lead to further apart of activity locations such as home and workplace and thus the need for longer travel time. On the other hand, the spatiotemporal constraints limit people’s time available for daily travel. Investigating the dynamics of the built environment and travel behavior will shed light on the constant travel time budget hypothesis.

To fill these gaps in the literature, this research is proposed to utilize data from periodical travel surveys that are usually conducted in major cities to investigate the built environment-travel behavior connection from a long-term dynamic perspective. We will first explore the dynamic trends of both the built environment and travel behavior over the course of decades. Methods like propensity score matching (PSM) and hierarchical age-period-cohort (HAPC) model would be used to address the age, period, and cohort effect in travel behavioral changes. We shall pay special attention to the trends of daily travel time to shed light on the constant travel time budget hypothesis. Further, we shall apply latent class structural equation model (SEM) to examine the long-term dynamics of land use impacts on travel behavior. We propose to conduct the empirical study in Shenzhen, China for the urban expansion and transport developments that Shenzhen has experienced over the past decades and the availability of large scale household travel surveys in multiple years. Academically, this research will enrich the literature on the built environment-travel behavior connection with a dynamic perspective and provide evidence concerning the constant travel time budget hypothesis. Practically, the outcomes of this project will deliver useful policy information for future urban planning and land use-based mobility strategies, especially for cities in emerging economies.