North Europe is pretty good for hitchhiking with lifts being plentiful around the Uk, Germany, Holland and even France on a good day. Things thin out a bit in Scandinavia and Spain and Italy are just the pits. The exception being between villages on the smaller roads where people tend to be more friendly anyway.
In France they have the peage toll roads that make your life difficult. The roads after the toll booths branch off in 1001 directions but if you hitch there then aggressive French police may come and intimidate you.
Here everyone hitchhikes. In communist times the government rewarded drivers with hitchhiking coupons and now the tradition lives on with the passengers paying instead. Expect a lot of competition in the hitchhiking equivalent of the survival of the fittest.
Here you’ll move fast as long as you stick to the tankstellen, the service stations. There’s no speed limit on the auto-bahn and people are pretty helpful.