Is there a way to delete the road that is bad placed in France sims 3

@FabiGinie  Thank you for providing a more detailed picture. I started a new game and sent my sim to France, and to that area. They had no problem routing on the road next to it. You did not answer my question if your sims are able to move about on the road without problem. Can they go to the house, and travel on the connected road next to that disattached piece?

Since my sim had no problem moving in the area, and that the disattached piece of road was unable to be interacted with, I think it is just an esthetic issue. If it bothers you for that reason you can try to remove it in the program Create A World. But the player that has edited out a lot of routing errors in several EA made worlds, including France, has not removed that piece of road. Appearantly it is a good thing, since it adds a Road Resource to the world, to be used in CAW. I am not sure I can link you the explanation, but search on ellacharmed, Mod The Sims, CAW, routing fixes, and World Resources for WA-worlds (adding sims 3 is always fruitful); and I'm sure you'll find it. If you want to try CAW there are explanations and tutorials as well as other players to ask, among other places at the EA Sims Forum:
https://forums.thesims.com/en_US/discussion/278761/caw-faqs-links-to-tutorials-and-resources-textures-amp-troubleshooting