Perhaps surprisingly, Newman and Thornley (1996, pp. 27-76) categorize the Dutch planning system as belonging to the Napoleonic family. The basis of the system, from which the characterization is derived, is formed by its broad legal context, which consists of a Napoleonic code and a written constitution. In the Netherlands, there are three levels of government: the national government, provinces (12), and municipalities (572 in 1997). Each level of government has clearly circumscribed legislative and administrative powers. Within those bounds, it is autonomous as long as it does not conflict with the interests of higher authorities. The national government provides a framework (in the Physical Planning Act of 1965) prescribing the procedures for the physical plans of the other levels of government. Additionally, national spatial policy is formulated in Reports on Physical Planning (regularly revised), which run through a special legal procedure, the so-called National Physical Planning Key Decision. The Reports on Physical Planning are meant to coordinate sectoral policies and provide provinces and municipalities with guidelines for their physical plans.