TTWAs are used for those involved in labour market analysis and planning as it is useful to be able to use data for zones that are labour market areas. More information on TTWAs, and a description of the methodology used in their creation can be found on the ONS website.
Travel to Work Areas (TTWAs) are zones defined where the bulk of their resident population work within the same area. The fundamental criterion used in their creation is that, of the resident economically active population, at least 75 per cent actually work in the area, and also, that of everyone working in the area, at least 75 per cent actually live in the area.