The way I see it, the risks of hitch hiking should be weighed against the risks of road walking, assuming that the hiker still intends to go to the town in question. Road walking on many mountain highways is dangerous and definitely unpleasant.
The other trade off might be to carry more food and resupply less in order to minimize or eliminate hitch hiking. This is what I'm tempted to do because I generally don't like asking people for favors (not just hitch hiking but in general) but I'm going to make an effort to get more comfortable with hitching this year. I see it as more of a mental block on my part than a real risk. If hitch hiking was really high risk, there would be many more people kidnapped or killed each year and we really don't hear very much about that kind of thing happening, at least when it comes to hitching from trailheads as opposed to the interstate.