Using virtual accessibility and physical accessibility as joint predictors of activity-travel behavior

In this study, we propose a conceptual and analytic framework anchored on the concepts of physical and virtual accessibility (the "ease" with which opportunities or activities can be reached in the physical and in the virtual space, respectively) to investigate the rich interplay between virtual and physical activity engagements in multiple activity purposes, while controlling for information and communication technology (ICT) use measures, physical accessibility measures, and demographics. Our framework considers that activity-travel choices are consequences of individual, household, and work characteristics that are mediated by virtual accessibility and physical accessibility. As part of our analysis, we also analyze activity chaining characteristics during travel to study any fragmentation impacts caused by ICT use on activity engagement and scheduling. We use data from the 2011 and 2012 National Travel Survey in Great Britain and apply Bhat's (2015) generalized heterogeneous data model (GHDM) to jointly model multiple activity and travel outcomes. Our results provide important insights for social welfare, work-life balance, and equity policies, and suggest that decisions regarding virtual activity participations and in-person out-of-home activity participations are determined as a package. Ignoring this package nature of choices can lead to misleading inferences about the effects of virtual activity participations on in-person out-of-home activity participations.