A Small Area is a particular locale within which the resident population tend to share certain key characteristics and behaviours. Small Areas are defined by the Office of National Statistics and the Scottish Government, based on Census Output Areas. They are the most suitable standard geography for the purposes of trend analysis, mainly because they have approximately similar populations and are not based on inconsistent and unstable foundations such as postal delivery routes or electoral boundaries.
The lowest level of Small Area geographies are known as Lower Layer Super Output Areas in England and Wales and Data Zones in Scotland, each of which has an average population of around 1,400. MAST uses a higher level of Small Area geography, known as Middle Layer Super Output Areas in England and Wales and Intermediate Data Zones in Scotland, each of which has an average population of around 6,600. This is because geographical collision trend analysis at the lowest level returns very low results for casualties and drivers, which lie below a sensible threshold for statistical significance.
Small Areas are derived from National Survey Grid References. In the case of drivers and casualties, the NSGR used is the centre point of their postcode. If no valid postocde is provided, the Driver Home Small Area or Casualty Home Small Area dimension will be Unknown. In the case of crashes the NSGR used is that reported by the reporting Police Force. For crashes where no valid NSGR was provided, the Crash Location Small Area dimension will be shown as EXACT LOC NK within the relevant district.
There is a map which displays MAST Small Areas for the whole of Britain on the Mast Mapping page of the MAST website. This map can be scrolled and zoomed at will. To see the MAST name and code for a Small Area simply click inside it.
For an explanation of Super Output Area in England or Wales, go to the National Statistics website
To search for information on a specific Super Output Area in England or Wales, go to the National Statistics website
To search for information on a specific Intermediate Zone in Scotland, go to the Scottish National Statistics website