Road accessibility and articulation of metropolitan spatial structures: the case of Madrid (Spain)

• This paper focuses on the spatial structure of metropolitan areas and their accessibility.
• Morphological polycentrism is analysed from a road accessibility perspective.
• The extensive metropolitan area of Madrid (Spain) is used as a case study.
• Results demonstrate the usefulness of spatial accessibility for studying polycentric urban structures.

In the last few decades, rapid growth in mobility has facilitated the inclusion of distant places in metropolitan processes and the modification of traditional metropolitan areas into Polycentric Urban Regions. This paper aims to understand the articulation of metropolitan urban regions through a diachronic road network accessibility analysis with a focus on the Madrid Metropolitan Region (Spain) over a period of general increase in accessibility. The findings reveal that the metropolitan core has been reinforced and that its influence area has expanded. However, the main contribution of this work is the proposal of a methodological approach to identify city-profiles among the sub-centres organising the emerging polycentric urban structures.