What will be the impact of the project on road traffic?

The creation of lanes dedicated to buses implies in some sectors a reduction in lanes for general traffic: from 2x2 lanes dedicated to general road traffic to a single lane (in each direction). In order to properly assess the impacts, traffic studies were carried out during the upstream phase of the study, to visualise the evolution of road traffic by 2035. They show that:

• Traffic levels in the area are expected to decrease on a very large portion of the route, in connection with the arrival of the Grand Paris Express, except on the RD40 on which road traffic is increasing slightly.
• However, traffic will remain heavy on the roads that are already widely used, with or without the implementation of a dedicated lane (lanes dedicated to buses). Indeed, a large number of vehicles circulating on the RD40 are in transit and do not exchange with the municipalities concerned by the TCSP project. The reduction in the capacity of the axis would dissuade these motorists from using the RD40, who would then prefer suitable transit routes such as the A104 motorway for example.

According to these initial studies, it appears that the implementation of public transport in dedicated lanes will not a priori deteriorate traffic conditions. Following the assessment of the consultation and as part of the studies (principle diagram phase), new traffic studies will be carried out with the aim of deepening, according to different scenarios and in conjunction with the local authorities, the impacts of the project on road traffic, to shed light on the choice of development that will finally be proposed to the public inquiry.