Type IV - Traffic Limitation
Represents urban areas that have efficiently implemented traffic control and modal preference in their spatial structure. Commonly, the central area is dominated by public transit. Limitations in the usage of the automobile in central areas are enforced for a variety of reasons, such as to preserve its historical character or to avoid congestion. Through a "funnel" effect, the capacity of the road transport system is reduced the closer one gets to the central area. Public transit is used in central areas, while individual transportation takes a greater importance in the periphery. Between suburbs and the central city are places of interface between individual (automobile) and collective transportation or between low capacity collective transportation (bus) and high capacity collective transportation (metro, rail). Several cities are implementing this strategy, namely through congestion pricing, as it keeps cars from the central areas while supporting the bulk of the mobility in the suburbs. This system typifies cities having a long planning history favoring public transit. London, Singapore, Hong Kong, Vienna and Stockholm are good examples of this urban transport structure.