Using geographical information systems to assess the equitable distribution of traffic-calming measures: translational research.

OBJECTIVE To assess whether traffic-calming features are equitably distributed in the UK. DESIGN Cross-sectional database utilising geographical information system (GIS) and population data. SETTING Four large regions in England and Wales, including areas in south Wales, south-west England, east Midlands and Surrey, for which map data were available. MAIN OUTCOME MEASURES The total proportion of road segments traffic calmed and the likelihood of road segments being traffic calmed by deprivation fifth. RESULTS A total of 3.7% of road segments was traffic calmed on 95,791 km of road length. A higher proportion of traffic-calmed road segments was found in deprived areas when population density was taken into account. The odds of traffic calming in the most deprived areas, compared with the most affluent areas, was 2.83 (95% CI 2.815 to 2.835). CONCLUSIONS High resolution map data can be manipulated within a GIS to enable the distribution of traffic-calming measures to be assessed over large areas. There are very few traffic-calmed roads in any area and there is scope for more. Deprived areas have substantially more traffic calming. Making such data available to the public should be tested as an advocacy tool to increase the provision of traffic-calming features.