I used to, and travelled all around the UK that way. I certainly met some characters - hippies, New Age travellers, the bull dyke lesbian truck driver, the guy who joked he'd stolen the car and then pointed out where he'd hotwired the ignition as he dropped me off, the sweet lesbian couple who let me stay with them in their lovely home for a couple of nights, the guy on the canal boat who could - and did - take me all the way to York provided I "didn't mind if it took a week or so", the chauffeur in the Roll-Royce who thought it'd be nice to have a normal person who wouldn't talk down to him in the car for a change, the old man who, having retired from the Army at 65, decided he'd wasted his whole life and was driving around trying to meet as many different types of people as he could...

Apart from a couple of bad drivers, I never had a scary experience, though there have been a few times I've refused lifts when something didn't feel right. Most people will try to help a lone traveller, especially a woman, rather than harm them; nevertheless, in a country such as the USA where pepper spray is legal, I'd most certainly recommend any hitch hiker and especially a female one keep a can of it somewhere easy to reach.

Very common form of transport in this part of the world.
Use your common sense when picking a ride or offering one is the best advice. It also helps that in central Brittany it is a very small tight community, and I have given lifts loads of times to someone whom it turns out knows us or I know their father/brother/ neighbour. On one famous occasion I gave a lift to a young lad, whose mother had given a lift to MY son the previous week.
Best one was was five dubious looking punk/leather types who were on their way to a festival. I knew one of them so gave him and his mates a ride to the nearest town. They were the sweetest, most polite bunch of lads you could wish to meet, kept trying out their English phrases on me and when I dropped them off I warned "Lots of water, not too much alcohol and stay safe" and two of them chorused " Oui, Maman! "
Jack - discouraged ? Wow, we have a network of hitchers to rides here called Epouce (Electric Thumb) where you can put out a call for a free ride from registered members.
Yes, there are lots of stories, but I know literally dozens of people at first hand who hitch around here, and not one has had an incident.
But thank you for your concern, Della, and for the record, a bunch of keys in a fist has helped me out of a tricky situation once, and that was being threatened on a busy street, with people walking past !

I havent hitchhiked since I was a teenager in the 70s. Even back then it was dangerous. I have some stories. Nowadays there is no way I would even think about it. I would definitely discourage it. It really sucks that you have no other option. Try to have some kind of self defense option handy. I walk a lot. I keep a pepper spray in my hand. Mostly for stray dogs if I feel threatened, but, it would come in handy for a human if needed.

Hitchhiking is discouraged in most parts of the country and illegal on the freeways. However, on the archipelago there is little public transportation and it is actually encouraged. I have picked up hitch hikers and also heard interesting stories.