Methods for delineation of functional regions using data on commuters

A functional region is a territorial unit resulting from the organisation of social and economic relations that is characterised by high frequency of intra-regional interactions. This uniform territorial unit often presents an important platform for development strategies of the country or region, and should combine different functions and their interactions on different scales. For their delineation one may consider different methods and different directly or indirectly geo-referenced data, such as population flows, trade in goods and services, communications, traffic flows, service connections, newspaper circulation, financial flows, etc. From the mentioned interactions, the daily interaction in the labour market can be considered as a good approximation for the functional region, and as such is used in most European countries. The paper analyses different methodologies for delineation of functional regions using only data on commuters between Slovenian municipalities. Tree methods were compared and tested: two already described in the literature, local labour market approach, and commuting zone approach and here suggested commuting aggregation approach. A case study for Slovenia was conducted.