This file contains the Standard Area Measurements (SAM) for 2011 travel to work areas (TTWA) in the United Kingdom as at 31 December 2011. All measurements provided are ‘flat’ as they do not take into account variations in relief e.g. mountains and valleys. Measurements are given in hectares (10,000 square metres). Four types of measurements are included: total extent, area to mean high water (coastline), area of inland water and area to mean high water excluding area of inland water (land area). The Eurostat-recommended approach is to use the ‘land area’ measurement to compile population density figures. The TTWAs used to create the Standard Area Measurements were built using Lower Layer Super Output Areas (LSOAs) created by ONS, Datazones (DZs) supplied by the National Records for Scotland and Super Output Areas (SOAs) supplied by Northern Ireland Statistics and Research Agency (NISRA). The DZ and SOA supplied for Scotland and Northern Ireland were clipped to the coastline. This means the extent of the realm and area to mean high water measurements are identical for Scotland and Northern Ireland. The Scottish DZ had some areas of inland water removed although not all, such as Loch Lomond and Loch Ness amongst others. Consequently the area to mean high water measurements are lower than they would otherwise be and the inland water measurements aren't as high as they would otherwise be.Click the Download button to download the file.