Why have some roads been paved in the forest?

The route of the T13 Tram extension will partly pass through the forest, reusing the right-of-way of the former Grande Ceinture ferroviaire, in order to reduce the impact on the environment as much as possible. To carry out the project, however, it was necessary to set up site accesses, only for the duration of the work. Once the work is completed, the roads concerned will be restored to their original state.