I'll offer up a fairly young perspective I suppose. I'm not sure if others my age agree, but as a 23 year old, I do not expect hitch hikers to pay anything other than common respect to the driver. Otherwise just friendly conversation will do just fine; I love to hear what people might be up to that led them to hitch hiking, whether it's for a backpacking trip, or to get across the states to visit a friend.

Now, granted, I will admit that many others around my age have a fear of hitch hiking or picking up hitch hikers. Everyone is convinced they've got a 50/50 chance that that stranger will be a psychopath. Same reason so many people are scared to meet someone from Craigslist at their house, or to let their 10 year old leave their street without a GPS tracking device and a cell phone.