Multimodal spatial availability: A singly-constrained measure of accessibility considering multiple modes.

Place-based accessibility measures communicate the potential interaction with opportunities at a zone that populations can access. Recent research has explored the implications of how opportunities are counted by different accessibility methods. In conventional measures, opportunities are multiply counted if more than one zone offers access to the same opportunity. This multi-count of opportunities leads to values of accessibility that are difficult to interpret. A possible solution to enhance the meaning-making of accessibility results is by constraining the calculations to match a known quantity. This ensures all zonal values sum up to a predetermined quantity (i.e., the total number of opportunities). In this way, each value can be meaningfully related to this total. A recent effort that implements this solution is spatial availability, a singly-constrained accessibility measure. In this paper, we extend spatial availability for use in the case of multiple modes or more generally, heterogeneous population segments with distinct travel behaviors. After deriving a multimodal version of spatial availability, we proceed to illustrate its features using a synthetic example. We then apply it to an empirical example of low emission zones in Madrid, Spain. We conclude with suggestions for future research and its use in evaluating policy interventions.

ICT use and spatial fragmentation of activity participation in post-COVID-19 urban societies.

With the outbreak of the COVID-19 pandemic, the use of Information and Communications Technology (ICT) came to dominate daily activities (e.g., e-working, e-shopping, and e-leisure). The intensive use of ICT might trigger higher levels of spatial fragmentation of daily activities, having significant consequences for planning purposes. This paper seeks to estimate how ICT use and habits affect the individuals' spatial fragmentation patterns in urban contexts on post-COVID-19 societies, while controlling for socioeconomic and built environment characteristics. The city of Alcalá de Henares (Madrid Metropolitan Area, Spain) serves as the case study. The research design is based on activity diaries obtained by face-to-face interviews, and Tobit and Poisson regression analyses are used to examine the relationships between spatial fragmentation measures (outcome variable) and ICT use (predictors). The results reveal that ICT might originate higher spatial fragmentation for work-related activities than for shopping-leisure purposes. For working activities, higher spatial fragmentation patterns are found among people with higher willingness to e-work and individuals who e-work at least once a month, but rather dependent on the occupation type. Regarding shopping and leisure activities, higher spatial fragmentation patterns are noted with car owners and more frequent consumers of online entertainment. The study provides insight into how ICT use is transforming spaces traditionally adapted for a single purpose into multifunctional spaces as well as the spatial effect of this phenomenon.