Abstract
Working from home (WFH) increased tremendously after the outbreak of the COVID-19 pandemic. A critical research need is to understand the associated impacts on travel behavior in the post-pandemic era, particularly on Vehicle Miles Traveled (VMT). In this context, we conceptualized a causal structure to investigate the interrelationships between WFH and VMT by considering non-work trip rates and travel efficiency as mediator variables. Travel efficiency is introduced as a latent factor, defined as a sustainability measure consisting of four indicators: activity-trip ratio, proportion of short-distance trips, proportion of micro-mobility trips, and proportion of travel time in non-auto modes. By applying a Structural Regression model based on the 2022 National Household Travel Survey data, we derived both direct and indirect effects of WFH on VMT. The indirect effect of WFH on VMT via non-work trip rates suggests that the frequency of non-work trips increases with the frequency of WFH, leading to an increase in VMT. On the other hand, the indirect effect of WFH on VMT via travel efficiency revealed that more WFH days induced more sustainable travel choices and thus contributed to reductions in VMT. The direct effect of WFH on VMT appeared negative, and the summation of both direct and indirect effects also resulted in a negative total effect of WFH on VMT. The findings of this study will provide important insights into the WFH arrangements and their impacts on travel behavior from several demand and performance measure perspectives, which will help policymakers formulate relevant post-pandemic transportation policies.