Priority to the right:
Never thought I'd be bringing this old chestnut up, as this quaint but confusing old practice seems to have all but died out in many parts of France, other than some small rural villages and towns. But having just returned from a week in Alsace, I have to report that it is alive and well and very much practiced there. Wherever a side road on the right doesn't have a give way sign or a solid line across the road, you can expect to have to give way to traffic coming from your right. Traffic regularly emerges from the right at speed at some junctions and ALL the locals give way. Driving in my car, on one occasion I reacted too slowly to a truck emerging from between two houses at speed, and didn't let him out. I got a long, angry hoot for my crime. Cars and bicycles regularly sauntered out confidently in front of me, and at the T junction coming out of our village onto the main road, traffic ALWAYS stopped dead to wait for us to pull out, even when we were turning left and had to wait for cars coming from our right to get past.
This doesn't seem to be an act of courtesy or kindness, as on one occasion I spent ages trying to pull away at the left of the road and, despite the fact that I was indicating and the traffic was extremely slow, nobody at all was willing to let me out. Then the moment someone turned up at a junction to their right, someone immediately gave way to him. The proprietor of the gite said the locals are very German in their outlook and attitudes (most of them speak a local German dialect), and they strictly obey all rules .... he cited the priority to the right rule, no littering etc. I wondered whether they are actually trying to prove just how French they are by sticking to French traditions longer than the rest of France. Either way, it is something to watch out for if cycling in Alsace.