Samenvatting
The Clean Air Act, adopted in December 1996 in France, oblige all cities over 100,000 inhabitants to prepare a mobility plan of sustainable transport. This plan has to include measures to decrease the car traffic and to develop the use of public transport, bicycle and foot. At the moment, in the Paris region, the traffic is increasing by 2% per year. In Paris region, the State has in charge this plan. It is a big challenge due to the size of the region (11.3 million) and the number of elected bodies with responsibilities in transportation.