【正文】 traffic and to affect modal choice, especially of the employees in favour of public transport. Parking management enpasses the entity of all measurements to steer parking supply and parking demand. Four adjusting screws are available: the amount of parking supply, parking prices and charges, parking period limitations with or without parking charges, privileges for certain user groups, such as, for instance, deliveries and residents. The success of all parking regulations within the public street depends strongly on their enforcement. According to its importance, enforcement could be called the fifth adjusting screw to steer parking. In the meantime, it is generally agreed that intensified enforcement is selffinancing through improved paying morals at meters and through ines by fines. But it is not easy to recruit personnel because of low wages and poor image. Parking management aims at balancing parking demand and supply by parking prices and by rationing the supply。 it can usually be avoided by extending the area of a parking management concept. 5. Parking regulations in zoning ordinances Originally, parking vehicles in the public street did not belong to the mon uses of a street。 or if a flat is devided into two flats, the parking space obligation is doubled. Basically, there are two ways of fulfilling the parkingspace obligation: first, to build the spaces on one39。R facilities are rather modest in quantity as well as in quality. Only Hamburg and Munich may be excepted from the general situation. The city of Frankfurt pursues an ambitious approach to multiply the number of parkandride spaces, preferably within the outer catchment area. Today, about 7,400 spaces are available for official parkandride and an unknown number of spaces around the railways stations of the neighbouring munities often within residential areas are used in a similar way. The investment costs of parkandride spaces are generally subsidised by the State of Hessen and the Federal State with 60%. The rest is financed by the City of Frankfurt out of the payoff amounts collected through parkingspace restrictions on private premises within the inner city. This financing model is applied in the same way in Frankfurt and in neighbouring and outlying munities. The Frankfurt parkandride concept is based on three screen rings. The outer ring is a broad area covering all munities with appropiate railway stations having easy car access. Car drivers heading for work are supposed to switch to public transport as early as possible, ideally within the area of their residential munity. Parking is free of charge. The second ring follows roughly the city border of Frankfurt with Pamp。Rinformation on the motorways tells about the parking conditions in the inner city, the nearest parkandride facility and the next train departure. Parking charges at the second ring are proposed to be moderate. Some 15 sites all around Frankfurt are planned or under study. Finally, a third ring enpassing the inner city residential and mixed use areas should snap up the rest of car drivers to work as well as shoppers and visitors to the city. These spaces are being considered to replace abolished spaces within the inner city. High progressive charges are proposed. Seven sites are planned or under study. Of course, the success of this ambitious parkandride concept depends on two prerequisites. One is the citywide consistent parking concept which is the responsibility of the city itself. The second is the cooperation of the other munities: some are more, some are less interested in getting parkandride facilities. Complicated negotiations concerning much more than parkandride have to be fought in the interests of the whole region. 7. Conclusions Out of all measures to freeze or even reduce motor traffic in cities, improvements of public transport and citywide parking concepts have key roles. One depends on the other: with public transport improvements alone, the car cannot be passed over and a high quality of public transport is a prerequisite for parking restrictions in inner cities bined with parkandride. Motor traffic restrictions in urban areas use two approaches parking restrictions and restrictions of traffic flow through capacity restraints at outlying junctions. Usually, both are bined. Parking restrictions are environmentally more favorable because they produce less noise, pollution and driver stress pared with trafficflow restrictions. Additionally, parking restrictions work selectively, that means they address the different user groups residents, employees, customers and visitors and mercial traffic in different ways. So easy access for residents and mercial traffic can result from parking restrictions against employees who usually can most easily switch to public transport and parkandride. Parking concepts distribute scarce parking spaces through administrative measurements as well as market rate measurements. Parking permits for residents, limitedperiod parking and parking charges are the most important instruments to control onstreet parking. Private spaces are distributed by useradvantages for car pools, reservations, longperiod rents and parking prices. In German cities, parking management in the city centres is most mon and has been successfully applied for many years. This has resulted in parked cars being shifted to the neighbouring residential and mixeduse areas, much to the detriment of those areas. The extension of parking management schemes from the centre to the whole inner city became possible with the legal introducton of residential parking permits in 1980. Currently, only a few cities have installed areawide parking concepts, although most have discussed it. But in the meantime, most politicians are convin