Abstract
Even though access to mobility and to free choice is guaranteed in Switzerland, it is becoming necessary to redefine the satisfaction of social needs through the construction of road network in a context of sustainable development. Decision-making methods must contain a specific facet for the problem of mobility as a basic social service. The approaches carried out recently in Switzerland bring innovative elements to decision-making processes without, however, giving an obvious priority to that social aspect. The notion of basic social service is not unanimously accepted and can only be totally integrated in a project if the protagonists concerned participate in the decision-making process. For the covering abstract see ITRD E135448.