Table 1.
Description and classification of objectively-measured neighbourhood and route environmental characteristics
| Environmental features | Description | Classification |
|---|---|---|
| Neighbourhood | ||
| Urbanization | Urban–rural classification of participants’ home location | Urban/rural |
| Road density | Total road lengths divided by neighbourhood area (km/km2) | Quartile |
| Proportion of primary road | Presence of primary road | Yes/No |
| Density of junction | Number of junctions divided by total neighbourhood area | Quartile |
| Effective walkable area (EWA) | Total neighbourhood area divided by the potential walkable areaa | Quartile |
| Density of pavement | Area of pavements divided by total road length | Quartile |
| Density of pedestrian infrastructure | Area of pedestrian infrastructure divided by total road length | Quartile |
| Number of streetlight per 100 m | The number of lights divided by road length per 100 m | Quartile |
| Household Density | Total number of household in the neighbourhood area | Quartile |
| Density of employment locations | Number of employment locations divided by area of neighbourhood per m2 | Quartile |
| Land use mix | Proportion of each land use squared and summedb | Quartile |
| Socioeconomic deprivation | Population weighted scores for neighbourhood | Quartile |
| Crime rate | Total crimes per 1000 population in area of residence of year April 2005 – March 2006 | Quartile |
| Density of RTAs | The number of RTAs 2002–2006 per km of roads | Quartile |
| Density of fatal & serious RTAs | The number of serious and fatal RTAs 2002–2006 per km of roads | Yes/No |
| Accessible land in neighbourhood | Presence of accessible land (all parts and green spaces) in the neighbourhood | Yes/No |
| Park in neighbourhood | Presence of parks in the neighbourhood | Yes/No |
| Green space in neighbourhood | Presence of green spaces in the neighbourhood | Yes/No |
| Route | ||
| Distance from home to work | The shortest route between home and work identified via the modified street network | <1.5 km |
| 1.5–4 km | ||
| 4-10 km | ||
| Route length ratio | Route length divided by the straight line distance between the home and school | Quartile |
| Main road on route | Presence of primary (A) road as part of route | Yes/No |
| Secondary road on route | Presence of secondary (B) road as part of route | Yes/No |
| Main or Secondary road along route | Presence of primary (A) or secondary (B) road as part of route | Yes/No |
| Number of streetlights along route | The number of streetlights along the route divided by route length per 100 m | Quartile |
| Route land use mix | Proportion of each land use within 100 m of route squared and summed | Quartile |
| Density of RTAs along route | The total number of RTAs occurred on route between 2002 and 2005 per km of roads | Quartile |
| Density of fatal & serious RTAs along route | The number of fatal and serious RTAs occurred on route between 2002 and 2005 per km of roads | Yes/No |
RTA Road traffic accidents
aTotal neighbourhood area is the area that can be reached via the street network within 800 m from the home and the potential walkable area is the area generated using a circular buffer with a radius of 800 m from the home
bSeventeen different land uses were classified: farmland, woodland, grassland, uncultivated land, other urban, beach, marshland, sea, small settlement, private gardens, parks, residential, commercial, multiple use buildings, other buildings, unclassified buildings and roads. This score is also known as the Herfindahl-Hirschman Index developed by Rodriguez and Song (2005)