Mike Brodie's freight-train photographs: 'It's a romantic life, at least in the spring and summer'

Going off on an adventure across the country like Huck Finn is a very American thing to do," says Mike Brodie, who did just that on a whim in 2003, aged 18. Unlike many of the young drifters he rode trains with back then, Brodie took his camera along and the p hotographs he took have finally been distilled into a book, A Period of Juvenile Prosperity, just published by the American fine art photography imprint, Twin Palms.

"I have mixed feelings about the photographs being in an art book and on the walls of art galleries," says Brodie, "and so do some of the kids I photographed when they come to the openings. You have a lot of worlds colliding right there. But most of them are cool with it, though, and happy that the photographs are being shown."

Brodie was living in Pensacola, Florida in 2003, still at high school and working part-time "bagging groceries in a grocery store" when, in true Huck Finn fashion, he decided to light out for the territory, albeit tentatively. The first train he rode illegally took him across Florida to Jacksonville. That three-day journey sparked a much bigger adventure lasting, on and off, until 2008, when he decided just as suddenly that he should "grow up and maybe try to settle down". Over that period he reckons he travelled around 50,000 miles by train, hiding in empty freight wagons as America sped by.

Along the way he encountered a few "veterans", but most of the kids he photographed rode trains for a few years as a kind of teenage rite of passage, more Jack Kerouac than Huck Finn. "A lot of the kids I knew have since gone back to their old lives. It was something they did for whatever reason before they settled down. Some were running away, some were out for adventure. It's like being homeless by choice, I guess, but, living like that you learn a lot of American values like self-reliance, independence."

Brodie's photographs made him, as he puts it, "internet famous" when he uploaded them under the moniker the Polaroid Kidd in 2004. Self-taught, he was given his first camera, a Polaroid SX-70, by a friend, but the images in the book were all shot on a Nikon F3 35mm camera. He was influenced, he says, by some Steve McCurry portraits he saw in a copy of National Geographic and by the photographs of Mary Ellen Mark, but is "not really that big on photography". Nevertheless, the American art critic Vince Aletti wrote of his style: "Even if you're not intrigued by Brodie's ragtag bohemian cohort – a band of outsiders with an unerring sense of post-punk style – the intimate size and warm, slightly faded colour of his prints are seductive. His portraits… have a tender incisiveness that is rare at any age."

Brodie's photographs of Corey, Blake, Rocket, Soup, Savannah, Lost, Trinity and the rest are also unashamedly romantic: all soft colour tones, wide open spaces and dirty, defiant, vagabond faces caught in the magical light of dusk or dawn. Does he think, in retrospect, that he may have over-romanticised the tough itinerant life of his subjects? "Well, I reckon photography always does that to a degree," he replies matter-of-factly. "But that life is romantic a lot of the time, at least in the spring and summer. So long as you like the outdoors life and you don't mind getting dirty and not having a change of clothes for months, it's pretty great."

There is something refreshingly unselfconscious about Brodie, not least in his seeming lack of artistic ambition. He has since given up photography and is now "trying to get a good solid career as a car mechanic", having graduated from the Nashville Auto Diesel College. "I've had a kind of spotty job career," he says chuckling. "So far, I just can't seem to stay put, but I'm trying. I'm still drawn to that old, free lifestyle. I still miss the trains, but I'm not a kid any more. I have to move on, settle down."

A Period of Juvenile Prosperity by Mike Brodie is published by Twin Palms

An exhibition of Mike Brodie's work runs until 6 April at Yossi Milo Gallery in New York and at M+B Gallery in Los Angeles until 11 May