Estimating a Polycentric Urban Structure. Case Study: Urban Changes in the Stockholm Region 1991-2004

The aims of this paper are to empirically test and evaluate methods for describing intraurban polycentricity, and to evaluate the polycentric development with respect to the regional development plan of the Office of Urban and Regional Transportation in 2001. The study area is Stockholm County and the time period investigated is 1991-2004. Three dimensions of polycentricity are analyzed: urban nuclei size relations, spatial distribution of urban nuclei, and potential interaction (accessibility). According to the methods' various qualifications in describing polycentric forms it is proposed here that a combination of methods is preferable for this subject. The polycentric structure exposes an increasing and considerable concentration of urban resources to the major urban nuclei. This concentration is combined with an increased spatial dispersal of the urban nuclei. In relative terms, the accessibility has decreased concerning the accessibility by public transportation modes and increased (workspace) or remained on almost the same level (residential space) by car transportation mode. Thus, the urban structural change in the Stockholm region corresponds to the political guidelines. In spite of this, by the increase in relative accessibility by car and decrease in the relative accessibility by public transportation modes the goal concerning higher share in public transports may not be possible to fulfill.