I had forgotten about those lines of trucks in the right lane of some Autobahns. We experienced it traveling on the A6/E50 heading from Rothenberg towards Heidelberg. Just a solid wall of trucks--not moving particularly fast. From just about every European country--and in various states of repair and age, and bumper to bumper.

Almost all the cars had moved to the left lane to avoid being in that mess, so the left lane wasn't going all that fast either.

And every once in a while one of those trucks would decide to pass the one ahead of it (probably out of boredom), and would proceed to do so going maybe 1 km/hr faster than the truck he was trying to pass.

Ah, almost forgot a couple of other items.

Especially when not driving on the Autobahn--do have your navigator watching the map carefully. As someone above pointed out, highway direction signs seldom give the number of the highway, just the names of the next 2 or 3 cities, towns, hamlets, or wide spots in the road--so when you come to a turning point, your navigator often needs to know the names of the next few towns on the route you want to take.

Also on secondary roads, some of the sections of road that are marked as OK for passing are very dangerous--going up hills, around blind curves, etc. This might be left over from the days when it wasn't unusual to get behind a "honey wagon" or other farm conveyance being pulled by a milk cow at about 1/4 of a km/hr--you could pass it in about 2 seconds with very little risk. But it doesn't work as well when you want to pass someone going 60 km/hr in a 70 zone.