The 30-min city and latent walking from mode shifts

Greater public transport use may occur through meeting average travel times of 30 min or less, termed the "30-min city". The quantification of public transport-related physical activity associated with the 30-min city is under-researched but needed to support policy interventions. In this study, latent walking steps associated with modal shifts from car use to public transport/walking are investigated using a synthetic population and trip planning tool in Sydney, Australia. Areas were identified where the largest opportunities for public and active transport investments could be made in terms of density of car commuters and potential physical activity. Analysis of socio-economics with mean potential steps and with mean travel times were also conducted. Mode shifts to public transport/walking that are within 30 min one-way commute time were associated with a mean of 1732 daily potential steps per car commuter. However, 57 % of car commuters do not have a potential public transport/walking alternative that can be made within 30 min, which supports the need to reorganise jobs and housing and/or invest in faster public transport modes. A focus should be on delivering interventions in areas with excessive commuting times. Interactive visualisations are presented to aid policymakers to encourage mode shifts to public transport/walking.