yep, wondered the same by myself. if there's much traffic, you have to keep full attention to it all the time. quite annoying of people don't stop even after an hour of waiting....

today i waited at a small "Parkplatz" along the highway with just some cars there, all having dinner or something around. I was just waiting at the end of the parking area and reading a book, and every 5-10 minutes a car came by I stopped and showed my thumb. Took me 45 minutes to get out of there, quite good compared to the traffic and filled-up cars :)