Geographers and planners today place an emphasis on spatial organisation that includes the notion of functional regions - areas defined by business and economic activities rather than by administrative boundaries are defined as the functional regions as regions which have more interaction with each other in terms of commuting than with other regions. In June 2004 the Department for Transport (DfT), UK, commissioned a short project to use 2001 Census journey-to-work data in two streams of work: creation of Balancing Areas for use in the next version of the National Trip End Model (NTEM); and creation of a system of Functional Areas/Regions to form the basis for future research on household and business location choice modelling. This paper presents the methods which were used to obtain a system of Functional Areas/Regions and the results of the project. The best-established basis for a functional approach to area grouping is to identify boundaries across which few people commute. Although commuting distances have lengthened over time to become very long for a minority of people, distance still has a significant deterrence effect and, as a result, for almost all areas predominant flows are to and from nearby areas. There are numerous boundaries among areas such as parishes or wards which are the common "building block" areas for which the data needed for regionalisation analyses can be obtained, and these boundaries will restrict the options as to which areas can be grouped at every step of an analysis which is explicitly contiguity constrained. To create the potential functional areas for England and Wales and for Scotland some analysis were carried out using a hierarchical clustering algorithm called Intramax procedure which is incorporated in the Flowmap software (van der Zwan et al., 2003). What the analysis does not provide is a justification for using any particular set of Functional Areas as the basis for any particular model, either at a national level or for any particular region or sub-region. Any such justification must depend on other characteristics, such as the perception of what constitute the alternatives for different types of locational decisions. These perceptions may well be very different for different types of actor - for example, the set of areas perceived as possible locations by a small, regional firm may be different from the set perceived by a large national firm. Moreover, some decisions may well be hierarchical in nature, even before getting down to the choice of specific locations or properties within the lowest-level area. For example, a multinational firm seeking to set up an operation in England may make a choice at the regional level before making a choice - on different criteria - at the area level. Different categories of households may perceive areas differently - for example, a high-income household with two specialised, professional workers might perceive the North-West as a small number of large areas, whilst a household consisting of unskilled workers might perceive the same region as a larger number of small areas (with perhaps only the closer ones being clearly perceived). It is not considered obvious that any one zone system is in fact appropriate for all purposes, even though that is the conventional approach to modelling and the present project has proceeded very much on that basis. For the covering abstract please see ITRD E135207.
Samenvatting