The year I turned 60, I discovered a way to travel back through time. The device? Hitchhiking.

Like many baby boomers, I used to hitchhike a lot. And, like many baby boomers, I quit. But I’d always been fond of the impromptu fellowship, and the small sense of triumph earned by actually getting where you’d wanted to go. (OK, I’d also liked the cheapness.) So two years ago I decided to attempt my longest hitchhike ever — more than 1,700 miles, from Minneapolis to Seattle — while I still could, to see if it was the way I remembered it.

Truck stops were bigger, and cleaner, and more plentiful. They sold fruit and kept the coffee fresh. (I’d known those things; I just hadn’t been quite so grateful while driving myself.) There were fewer vehicles trailing clouds of burned oil, or running down the road off-kilter, like injured dogs. VW vans driven by hippies who would always pick you up — gone completely, of course.

As for me, I had an AARP card in my wallet. My backpack weighed 29 pounds but felt like 50. Standing on a sloping highway shoulder gave me a kink in my back, so I had to stretch a lot. I refused to camp out.

Also, the waits for rides were much longer than I remembered. Three hours on the shoulder in Missoula, Montana, a college town? That wouldn’t have happened in the 70s. Of course, I didn’t exactly look like a college student, either.

But I found it’s still true that there are only two types of people on the road: those going your way, and those going the other way. And the drivers who picked me up still had the same motivations. They were on a long trip and wanted someone to talk to. Or they’d been hitchhikers themselves at one time, and were returning the favor. Or they’d picked me up because God wanted them to. (That idea goes way back.)

The joy of a road trip is how it can put you firmly in the present; you are now here, and then there, experiencing time and place as a single but ever-changing phenomenon. And yet, on the morning of the fourth day of my trip, present dove into the past. Bored and shuffling around on the shoulder at Three Forks, Mont., as little traffic came by, I happened to notice some rusty writing on an entrance ramp light post: “Rainbow Krystal,” it said. “7/1/81. Good Hitching to you all. The Mosquitoes are fierce!”

I may have gasped. Almost exactly 30 years before, Krystal had stood in that very spot, idle and hopeful, tuned into the mosquitoes during the long stretches of silence between cars. In seconds, I’d been taken back three decades, only to meet a traveling companion, in what certainly was another lifetime.

It happened again the next day as Claude, sharing his Audi convertible, carried me through the Cascade Mountains, well off the beaten path, to Twisp, Wash., where I’d told a friend I was coming to visit. Claude told me of his and his late wife’s hitchhiking trips through Europe years before, and I suspect we both knew how lucky he’d been for that experience. Just under our conversation, an intriguing, extended instrumental jam flowed from his satellite radio, then filled a stretch of silence.

“Who are we listening to?” I asked.

“The Grateful Dead,” he said.

Truly: The emblematic band of the Baby Boom was now on the soundtrack to my 2011 Tour. I should have recognized them. But in that sweet little time machine, in that place and time, they sounded new.