Impact of commuting, time budgets, and activity durations on modal disparity in accessibility to supermarkets

Urban spatial structure, transport mode and space-time constraints are known to affect accessibility to activities for a city’s residents. However, most studies measure accessibility from home only and report accessibility in terms of the travel time or number of activities. Such studies neglect the mobility and time budget constraints on people’s accessibility. Furthermore, modal accessibility disparity studies have not considered inequality between modes during the afternoon commute. We examine accessibility to non-work activities by automobile and public transport using spatiotemporal measures that determine the number of minutes people have available to participate in activities, given time budget and activity duration constraints, rather than simply the number of activities. We examine modal accessibility disparity in Warsaw, Poland. Our two major findings are the reverse of findings in previous studies: that disparity shifts toward public transport as the activity duration increases and the travel time decreases; and that it shifts toward public transport with increasing distance away from the city center