Exploring the causal effects of the built environment on travel behavior: a unique randomized experiment in Shanghai

Experimental designs have been recognized as the gold standard for establishing causal mechanisms. However, the application of such designs is complicated by factors such as excessive costs, time consumption, ethical concerns, and political impossibility. Nevertheless, the Chinese government's replacement housing efforts provide a unique randomized experiment for exploring the causal effects of the built environment on travel behavior. Accordingly, based on a large-scale survey on travel patterns under an experimental design in Shanghai, this study employs a two-step modeling approach, involving logit and Tobit models, to identify the built environment's effects on auto ownership and vehicle kilometers traveled (VKT). We found that transit service improvements play a stronger role in reducing auto-drive than compact and diverse land-use characteristics. Increasing residential and employment density, as well as land-use mix, discourages car ownership, which in turn reduces VKT, but with lower elasticities than transportation system variables. The findings provide additional evidence and referential estimate for how land-use and transport strategies and policies designed to create a compact, mixed-use, and highly accessible built environment can be used in reducing auto driving. This study expands the VKT reduction elasticities' database regarding the built environment across global spatial contexts, serving as a model for similar studies elsewhere in the world.