Once we got to France we were almost constantly lost. Once you get on those highways in the wrong direction there is no turning back until a toll stop and many kilometers later... for some reason we were being pulled toward Paris a couple of times. The "wrong way" sign was developed when we found out we were following another car in the opposite direction of our destination. Since we ourselves had problems navigating most of the time we thought it might be helpful to leave the sign on all the time (in case somebody tried to follow us).