It was once all too common to drive down a two-lane highway and spot a stranger on the side of the road, thumb out, a bag slung over their shoulder or resting by their side. During the Great Depression, jobless Americans thumbed rides from strangers as they traveled far and wide in search of opportunity. Amid World War II, picking up a hitchhiking soldier became a patriotic duty. The practice later became associated with the hippie lifestyle of the counterculture movement—a chance to break free from the status quo. “For quite a number of decades, it was not considered a...