In this article, we analyze the relationships between urban form, accessibility to transport networks and commuting practices through a scale of functionality intermediate between the traditionally studied local and metropolitan levels. A detailed description is provided for the generic methodology used to construct harmonized mesoscopic zones based on commuting data. These zones are applied for the Paris and Rhine-Ruhr (Germany) regions. Daily commuter mobility (transport modes used, distances traveled, and local portion of trips) is then analyzed for this intermediate scale. We emphasize the necessity for accessibility measures for each level described.