These parts of a catchment area are often described in terms of the distance between customers' homes or workplaces and the area or site. They are usually delineated by measuring linear distance (e. g., concentric circles drawn around a site), travel distance (by car or public transport) or time distance (by car or public transport). Mapping techniques are used to forecast or survey and map such store trading areas (McGoldrick 2002, p. 247).