The impact of street network connectivity on active school travel: Norway's HUNT study

Active travel to school (ATS) is promoted due to its benefits for health, mental well-being and the environment. Although the impact of the urban form on ATS has been extensively researched, findings have remained contradictory. Existing studies have mainly relied on aggregated, area-based measures, scarcely applying disaggregated, network-based measures of accessibility, street configurations, connectivity or urban density. This study addresses issues related to aggregation and the lack of ATS-specific network measures to evaluate the connectivity of routes to school. We examined the associations of route betweenness, reach and weighted reach with ATS, while adjusting for age, gender, traffic and proximity to school. Population data are disaggregated within a 50-m accuracy of address points. We introduce 'route betweenness', a new network-based measure for assessing the connectivity of entire shortest routes. We measured network accessibility around homes as reach (i.e., the number of streets reached through the network), and urban density as weighted reach (i.e., as the floor area or population accessible within walk-/cyclable distances). ATS was measured through self-reported walking or cycling to school (yes or no). The results show positive associations of route betweenness with ATS. The findings further indicate that, whilst higher connectivity and accessibility around home can increase ATS, the connectivity of the network along the way to school, as grasped by route betweenness, is even more important.