We love these signs when we're touring. In our motorhome we're normally going slow enough that we can just turn off the autoroute or else log interesting sites for a future trip.

I'm British-Canadian so the European roads hold no fear for me. I'd say to any worried North Americans (roundabouts, kms, aires), just do it some time - France in particular is a chilled place to drive motorhomes (RVs if you must) and I've never had any grief. We avoid Paris and other dense urban areas, but the beautiful countryside and easy autoroutes make for an excellent tour. We're off to Norway next month and I hope the signage is as interesting.