Driving on the Autoroutes - especially if you're not totally used to driving on the right - can be pretty disorientating.
The French manage to add an additional twist to the situation though; distances shown on signs may not be what they appear!
The problem is that when you see a sign saying "Le Mans 179", it means Le Mans may be 179km away but only if you take the shortest route. If you stay on the Autoroute you are on it is likely to be a fair bit further. There are even cases where you can see a sign giving distances to a place - and 10km down the road see another sign saying you are further away from the place you are heading to than when you started. This is particularly noticable around Rouen.
There is a way to know how far you have yet to travel on an Autoroute before you reach somewhere, but only if that place is the end of that particular road. In the middle of the road on the concrete divide there are signs giving distance to (or from) the end of the Autoroute every kilometre (and sometimes every 200 metres as well). This is fine as long as you know where the road ends. On the A28 the signs (in both directions) show how far from Tours you are.
Of course, on the railways it is different; not only do they drive on the left, but the distance - to Paris - is always accurate.