I hitchhiked over 30,000km in the last few years in many countries of Europe and Asia. I would claim that people have usually gross misconceptions of the risks. It is of course very dependent of who and where you are and which techniques you use, but I would say that the risks involved are on par or rather much less than traffic accidents. Western Europe countries tend to be slightly harder because the people are more afraid, and as I'm kind of sick of these societies rooted in fear I don't think I would want to go to the US. Besides, at least in Europe and Asia, hitchhiking works everywhere if you know how to do it, and it's a more fulfilling way of travelling than anything else I've done.
https://www.change.org/p/volvo-european-commission-volvo-sho...