Here We Go Magic/Secretly Canadian

An advisory to readers who may be driving on this Memorial Day weekend: If, as you travel the nation’s highways, you spot a hitchhiker with a wiry build, a pencil mustache and a mischievous look in his eyes, you may not wish to pick up this person. Unless, of course, you are certain it is the cult filmmaker John Waters, thumbing his way across the country in search of material for a new book.

This is not as improbable as it might sound. In recent days, an indie rock band from Brooklyn, a married couple from Illinois and a young lawmaker from Maryland have all reported unexpected road encounters with Mr. Waters, the 66-year-old writer and director of such willfully trashy movies as “Desperate Living,” “Polyester” and “Hairspray.”

On a trip that Mr. Waters said took him eight days and about 15 hitchhiked rides to get him from one end of the country to the other, he has accumulated numerous anecdotes for a book he has tentatively titled “Carsick” and which will be published by Farrar, Straus & Giroux.

But more crucially, he said this journey has taught him that it can sometimes be thrilling to not know where life is taking you.

“My life is so over-scheduled, what will happen if I give up control?” Mr. Waters said by phone from San Francisco, where he was safe, sound and still surging with adrenaline.

In doing so, he said he encountered a true cross-section of America: “Pot smokers, cops, I got everybody. And everybody was lovely.”

Having started hitchhiking at an early age, Mr. Waters said he had had only positive experiences in the past. “I never had a scary person, really,” he said. “When you’re young, people come on to you a lot more.”

Since those days, Mr. Waters grew into the transgressive director who dreamed up the filthy family rivalry of “Pink Flamingos” (and its excremental denouement). More recently, and perhaps more improbably, he has become an avuncular ambassador of sleaze culture who has seen “Hairspray” transformed into a family-friendly stage musical and movie adaptation.

Even so, Mr. Waters said he got a wide range of reactions from the people he briefed in advance of his latest trip. “Everyone my age that I know was so horrified by this idea,” he said. “Every young person I know said, ‘Can we come?'”

Before setting off alone from his Baltimore home on May 14, Mr. Waters said, he wrote preliminary chapters for his book, describing the very best and the very worst fictional hitchhiking experiences he could imagine. But he declined to provide further details about these chapters and, when told by a reporter that he could envision many horrible things happening on the road, he replied: “You think I can’t?”

Instead, Mr. Waters enjoyed many best-case scenarios. On May 16, he was picked up on a stretch of Interstate 70 in Ohio by the rock group Here We Go Magic, whose members could not quite believe that they spotted him by an exit ramp.

“Half of us thought that he wasn’t John Waters, because that would be impossible, and half of us thought that he was,” said Michael Bloch, a guitarist for the band. “So we argued about it for one exit, and the only way to resolve it was to just turn around and go back.”

Though Mr. Waters jokingly compared the band to the Manson family, Mr. Bloch said they found him an enjoyable travel companion before dropping him off in Indiana.

“Just giving himself up to the winds is something that he really wants every once in a while,” Mr. Bloch said. “We all found that really inspiring and really eye-opening.”

Early – and later – in his odyssey, Mr. Waters chanced upon Brett Bidle, 20, a town councilman from Myersville, Md., who was en route to Joplin, Mo., to help with tornado relief efforts there. Mr. Bidle first drove Mr. Waters from Myersville to Ohio, then reconnected with him in Denver, driving him another 1,000 miles to Reno, Nev.

“I drove for 22 straight hours with no sleep, whether that was a smart thing to do or not,” Mr. Bidle said on Friday, speaking by phone from Wichita, Kan. “I was on a mission to find John Waters again.”

Mr. Waters also made arrangements for Mr. Bidle to stay at his apartment in San Francisco, where Mr. Waters arrived on Tuesday after four more hitchhiked rides.

“I thought, you know what, he wanted an adventure, too,” Mr. Waters said of Mr. Bidle. “He’s the first Republican I’d ever vote for.”

Mr. Bidle said of Mr. Waters: “We are polar opposites when it comes to our politics, religious beliefs. But that’s what I loved about the whole trip. It was two people able to agree to disagree and still move on and have a great time. I think that’s what America’s all about.”

Mr. Waters said he was never stopped by police when he hitchhiked and never felt that he was in danger. But picaresque fantasies aside, there were times, he said, that the enterprise was “deadening.”

“You think maybe you’re standing by a highway for a long time, it’s a Zen-like experience,” he said. “It isn’t. It is a despairing experience to figure: No one’s ever going to stop. I’m here forever.”

Over all, Mr. Waters said he was fascinated to see what happened when he cast aside any vestiges of celebrity and threw himself to the vagaries of the road. “There’s not an airport in the world I’m not recognized in,” he said. “But who thinks it’s you on the side of the street?”

About a third of the people who picked him up, Mr. Waters said, had no idea who he was and another third were convinced by his explanations (or by a Google search) that he was a personality of some renown.

And all his other benefactors, Mr. Waters admitted, had him made right away. “My mustache got me a third of the rides,” he said. “I had it working.”