Your thumb is out. You're heading that-a-way.

Now you wait. Do people stop for hitchhikers these days? You wonder, as you stand by the road, cars zoom-zooming past you, breeze ruffling your hair. Is it safe to hitchhike in America 2020, or, as in the new book "Roadside Americans" by Jack Reid, are those days long gone?

In 1932, a young man traveling from Dixon, Ill., to Davenport, Iowa, stepped to the side of the highway and stuck out his thumb. The country was in the grip of the Depression then, but Ronald Reagan made it to his new job just fine.

Though many boomers spent their youths with thumbs cocked, we tend to see hitchhiking as a quaint anachronism today. In Reagan's youth, however, when few people owned vehicles, catching a ride with a friendly stranger was a way for adventure, as well as a mode of travel and, buoyed by an innocent sense of safety, white men and women hitchhiked in relatively equal numbers.

When the Depression hit, hitchhiking's role in American society increased greatly, though it had its detractors.

That cynicism lasted until World War II, when folks felt it was one's "duty" to offer a ride to a soldier on the side of the road, often regardless of race; likewise, it was neighborly to do the same for someone stranded by rationing. The government even advocated ride-sharing as a patriotic thing, which most Americans embraced.

Between 1964 and the mid-'80s, hitchhiking was part cheap transportation, part meditation. It was a way to see the country, to learn about one's self, and to touch base with America. Reid calls it a chance at "authenticity," though it was becoming a lesson in frustration. The country was changing. Roadside camping had lost its charm. Vehicle ownership was getting cheaper. Then there were matters of "personal safety."

It's a dangerous ol' world out there, right? Hitchhiking is for fools — or so you say. Maybe your grandmother did, too. Author Jack Reid says our attitudes toward hitchhiking have ridden a wave that rose and fell like a hilly road.

That road is not without potholes.

Though it's an essential look at history that isn't often examined, "Roadside Americans" is good, but it's repetitious enough to be noticeable. That's one thing; the bigger surprise is that it doesn't feel very new, since a lot of hitchhiking's story is linked with major, oft-studied events in America's past. If you've read about them, you've read much of this.

Yet, there are nuggets contained herein, often in the diaries and firsthand accounts that Reid shares, and in the statistics he presents from contemporary polling. These show a side of hitchhiking as he describes it: necessary, useful and frightening. Those nuggets are perfectly placed, just where this book glows.

Though it leans more toward the scholarly, "Roadside Americans" ends up being a decent, even delightful, read that's perfect for trippers, former hippies and history buffs. If you're armchair traveling this summer, it gets a thumbs-up.

"The Bookworm" is Terri Schlichenmeyer. Terri has been reading since she was 3 years old, and she never goes anywhere without a book. She lives on the prairie in Wisconsin with one man, two dogs and 16,000 books. Look for her at bookwormsez.com or bookwormsez on Twitter.