Centrality describes the geographic location of a municipality in relation to urban settlements divided into three levels according to population and available public services. Level 3 are regional centres with a population of at least 50 000, level 2 settlements between 15 000-50 000, and level 1 between 5 000-15 000. In order to describe the alternatives for travelling time to one or more urban settlements, the municipalities are divided into four centrality levels (0-3).