I did some hitching in europe. it was awsome. Usually it was former hitchhickers who took me along. And one really cool, kinda odd truckdriver once.
I felt save, though had on two occasions not such good drivers. Nothing happened in the end, so turned out allright. but looking back on my total hitching exprience, i would certainly recommend it!
Went from switzerland to home (north of the netherlands) where i got dropped at the door of a youth hostel in frankfurt, and later on my frontdoorstep. (and i live in the middle of freaking nowhere, this guy just took a huge detour to bring me home).
second time i went from barcelona to london. wich was superb. i met this crazy truckdriver, who was super skinny, very spiritual, and only ate fruits, nuts and seeds, 'of course' all uncooked.
I would just say, go for it. trust your intuition of course, and if you dont find a ride, i think it is pretty safe to sleep in a gasstation on the highway.