Table 1 Built-environment characteristics calculated along GPS and SNR routes in PostGIS; including how built-environment characteristic was defined and data source
Built-environment characteristic | Definition | Data source |
|---|---|---|
Length of route (km) | Length of route in kilometres | Line geometries were downloaded from OSM [34] |
Bluespace (%) | Percentage of route along visible water (e.g. river, canal) | Bluespace polygon data were downloaded from OSM [34] |
Traffic lights (n) | Total number of traffic light signals along route | Traffic light point data obtained from OSM [34] |
Accidents (n) | Total number of police-recorded traffic-related incidents along route | Road traffic accident data was downloaded from Stats19 [35]. Accidents that occurred between the school commuting hours (7:30–9:30 and 14:30–16:30) were extracted and represented as point data |
Type of street (%) a. Main road b. Residential c. Minor Road d. Footpath | Percentage of route along this road type | The OSM road types were aggregated into four road classifications that have been used in the literature [11]: main road, minor road, residential road and footpath |
Woodland | Percentage of route that has woodland within 25Â m of the route | Woodland polygon data were downloaded from OS Meridian 2 [36] |
Food outlets | Total number of food outlets within 100Â m of route | Postcode level food outlet point data were downloaded from the Food Standards Agency [37] |