A literary journey across the United States aboard a Greyhound bus

Scott MacMillan traces the route taken by the hero of Jack Kerouac's novel On The Road.

One can't help but wonder, travelling across the US by bus, how it is that America has created one of the most advanced civilisations the world has ever known, yet also produces the people who ride the Greyhound. In Rochester, New York, a lady sits at the front of the bus and hands coin-sized plastic smiley faces to all those who board. "Here's a smile for you, and one for you to share with somebody else," she says. "It's a gift from the Ambassador of Kindness to the USA!" Thank you, I tell her, cautiously moving towards the back. It was last October, coinciding with the 40th anniversary of Jack Kerouac's death, when I set out on a 10-day overland journey from New York to San Francisco, following the first cross-country route taken by Sal Paradise, Kerouac's alter ego in his 1957 classic On the Road. Set in 1947, the book is a celebration of American freaks, misfits and those otherwise unhinged - and there's plenty of each on the bus from New York City to Cleveland. A grizzly man who looks like a retired Hell's Angel, sharing tales with whomever will listen about his encounters with the law; an African-American who talks like a white man imitating a black man, going to Cleveland to visit his woman and child and to "stack my bread"; a girl with platform heels so high she has trouble walking; and, of course, the Ambassador of Kindness.

After we set off, the Ambassador comes to the back and describes her mission, citing a litany of statistics: so many years of abuse, so many hospitalisations, so many suicide attempts. She tells of the transformative moment when a fellow in-patient unexpectedly thanked her for her smile. "I realised I was healing myself through Acts Of Kindness," she says, "and that I was A-O-K." She points to the three letters in the air in front of her, like the bouncing ball in a TV sing-along. "And that I could also be an Ambassador of Kindness, and that is A-O-K." She's even got a business card. It's really a touching story, yet one can't shake the feeling that the Ambassador's got a small hatchet hidden in the small of her back, and that at any moment you might find its sharp edge lodged in your forehead. Sal Paradise would have loved this bus. For him, the truest American character was Dean Moriarty, a wino's son who grew up in Denver begging for change to bail his drunk dad out of jail. The father repaid the favour by disappearing without a trace, and Dean - modelled on Kerouac's friend Neal Cassady - split his adult life between the library, pool hall and jail. As unpleasant as he may seem, Dean is Sal's muse, as was -Cassady to Kerouac, and On the Road is the story of the narrator's man-crush. From New York, Sal ploughs through to Chicago, but I stop in Cleveland, Ohio, paying an obligatory visit to the Rock and Roll Hall of Fame, a slick museum that houses costumes and artefacts ranging from David Bowie's Union Jack suit to Jim Morrison's Cub Scout uniform. More intriguing is the Town Fryer, a Cleveland eatery known for its deep-fried Twinkies. Heading down Superior Avenue - the historic Route 6, Sal's main route across the country - I pop into an art gallery to ask for directions.

"This is not the safest area to be walking around at night," says Maria, who's selling tickets for an improv comedy troupe. Since it's raining, she offers me a lift, but the Town Fryer is closed - no deep-fried Twinkies tonight - and instead I'm treated to a short driving tour of Cleveland. Maria gives me the lowdown on the city's thriving theatre scene, then drops me downtown and drives off into the drizzling Ohio night, "off to whatever fate awaited her", as Sal would say. I relish these chance -encounters of the American road, not to mention Maria's willingness to take a risk - for if it's not safe to walk around at night, surely it's equally unsafe to offer lifts to total strangers. The Greyhound plunges through the pitch black Indiana night towards -Chicago, where I crash at a friend's place in the Loop, the city's historic centre. Sal briefly wanders the streets here to a soundtrack of bop, the jazz style that was "going like mad all over America" in 1947. Today's Chicago's jazz is too rarefied, but one afternoon I pop into the Billy Goat Tavern, a legendary pub with red-and-white chequered tablecloths that opened in 1934 across from the Chicago Tribune offices. The sweet scent of old tobacco mixes with that of splattered grease, while behind a marbled linoleum counter the bartender still uses the cash drawer of the old analogue till. "Schlitz was the number one beer in the country until 1976," I overhear one patron tell another over the sound of a Yankees-Angels playoff game. "But then they changed their formula." A nugget of classic American bar talk in the classic American bar town. Though Chicago doesn't feature strongly in On the Road, Kerouac captures the subterranean feel to this place, a city of gleaming skyscrapers that somehow retains the whiff of a dank speakeasy from the days of Al -Capone - or a crowded jazz club from the days when jazz was still mind-bending and poetic and new.

Sal's already run out of cash by -Chicago, so he starts hitch-hiking his way across the Great Plains. We rent a car instead. Fields of corn and wheat soon flank both sides of Interstate 80, built in the 1950s under President Eisenhower, though Sal's Route 6 is still visible, set back from the highway, the old road running up and down in undulations past houses, barns and grain silos. By dusk we cross the Mississippi, sleeping in a casino boat on the great muddy stream in Bettendorf, Iowa, and winning back the cost of our hotel room on the slot machines. Beyond the Mississippi, the tops of man-high corn stalks shimmer like the ocean. Sal moved west largely in the cabs or on the beds of trucks, so when a towering sign announces Iowa 80, the world's largest truck stop, we pull over for a poke around. I find a veteran trucker named Ace loitering in front of a few hundred parked 18-wheelers. "I'm just waiting for the dispatcher to tell me where to go," he says. "I came from Cedar Rapids [Iowa] and now I'm aiming to get back to Laredo [Texas]." That's a mere 1,300 kilometres, a jaunt for this road warrior.

Ace says he doesn't take many hitch-hikers. It runs against company policy, to start, not that he's much concerned about that. "Sometimes, but I'll usually talk to them first. Like if I see them at a truck stop with a lot of bags, I might start talking to them." Hitch-hiking, sadly, is largely a thing of the past in America, due mainly to concerns about violent crime - an irony, since the country as a whole is probably safer than at any time during my lifetime. Sal might have a rough time of it today. We're interrupted by a younger man with shaggy hair and a slightly bewildered look. "How far is it to North Platte?" he shouts across the pavement. "My dispatcher just sent me a message, asking me why I'm stopping." Trucker talk ensues, Ace advising Shaggy to lodge a complaint with the DOT - that is, the federal Department of Transportation - if his employer is pushing him to drive too many hours. Ace invites me back to see his cab, but we have to press on.

Having our own wheels allows us to pop into places such as Stuart, Iowa, population 1,712, where Sal tries to sleep outside the railway depot but is kept up by the racket of the telegraph machine. I ask a man washing an ambulance - surely the town's only ambulance - where the old train station is. "That's it right there," he says, pointing to the small brick building across the street. "They just painted it." From the level of detail in the book, Kerouac himself must have passed a sleepless night here. Odd, then, that he doesn't mention the town's sole attraction: the former First National Bank, robbed by Bonnie Parker and Clyde Barrow in 1934. Fittingly, it's now the Stuart Police Department. The stark desolation of the Plains town of Shelton, Nebraska, becomes a sort of recurring joke in On the Road, with Sal periodically reflecting on the hours spent waiting for a lift there, where the only sight to behold was a water tower declaring "Shelton" and the main event was when the Rock Island, an old boxcar rail line, "balled by". By the time we reach the town, much of Nebraska is covered with a wet and miserable snow. The water tower is nowhere to be found; the only sound is a grain elevator next to the railways tracks, and the only smell, burning coal. Shelton, sure enough, is still a synonym for bleakness.

A sign outside a Shelton convenience store advertises "Fresh Piccadilly". Assuming this to be a speciality of regional cuisine - a Nebraska corn dog with pickles, perhaps? - I pop inside. "What's Piccadilly?" I ask the young clerk. "We have burgers, pizza, whatever you want," he replies. "Yes, but what's Piccadilly? The sign outside says Piccadilly. I'm not from around here, and I'm just wondering what Piccadilly is." "Burgers, pizza..."

The conversation goes around in circles until I realise Piccadilly is a frozen-food brand, and "fresh" means they'll cook it for you on the spot. (Later research reveals Piccadilly Circus Pizza is indeed an Iowa-based company that provides fast-food solutions to convenience stores.) As we're readying to hit the road again, the main event happens. Covered in snow, a Union Pacific locomotive balls by, 55 boxcars in its wake. I stand next to the tracks, swept by the deafening roar, feeling a rush of damp air and the wayward ghost of Sal Paradise. Onward through Nebraska, we gain an hour entering Mountain Time Zone, and the landscape of seemingly endless grain fields slowly shifts into rangelands of low scrubby hills. The patient eye can sense the beginning of the American West. On the High Plains of western Nebraska, we spot the first bluffs, mounds of raw earth with eroded cliff faces, and then, approaching the Wyoming state line, small oil wells with pumps resembling cranes dipping their beaks into the ground.

Old Cheyenne, where Sal witnesses the sad charade of Wild West Week, a festival of all things cowboy-related, is practically asleep when we pass through, so we drive past the "entry prohibited" signs to enter the area of the railway roundhouse, the repair yard. It's an arresting sight, with vivid painted rail cars set against an azure sky that seems to have grown twice as wide since New York. In the opening chapters of On the Road, Denver beckons like a promised land of "old bums and beat cowboys". Our Kerouac journey peaks in the mile-high Colorado capital with a self-guided driving tour to the cafes, pubs and neighbourhoods associated with Kerouac, Cassady, Allen Ginsberg and the other Beat writers. The tour ends in the residential Lakewood district, where Kerouac bought a house with the $1,000 (Dh3,670) advance for his first published novel. He lived here while researching On the Road, even writing parts of it in this house, but there's nothing to mark the site. It's just another American suburban home, an old one-storey ranch dwelling with two trailers in the driveway, lying low beneath the Colorado sky.

The Beat generation caught the last days of old Denver, once a rickety prospector's town of Victorian-era saloons. Today's city is a world apart. The historic heart of Denver, Lower Downtown or LoDo, has been rebuilt as a shopping area, and on pedestrianised 16th Street free buses whisk people from one corner to the next. A security guard rolls out a ramp for an unkempt man who appears to be living out of a shopping cart. He probably has it better than Dean Moriarty's long lost father. It's a freakishly clean place. On a downtown street corner, two Denver municipal workers are drilling a hole in the pavement, one holding the drill while the other uses a vacuum to suck up the dust that might otherwise sully the spotless sidewalk. The odd spectacle points to the way America's rough edges have been polished smooth since the 1940s, a process that seems to have culminated, for my generation at least, during the booming 1990s, the age of Starbucks and soccer moms.

The country's recent economic troubles have done little to blemish the bland surface sheen of prosperity. Even if the changes are largely for the better, the tidiness seems a tad excessive at times. On the Road continues for several hundred pages, and truth be told, much of it is a rambling bore - a bit like some parts of America, come to think of it. But I've always felt the book redeems itself in its heartbreaking final paragraph, when Sal sits on a pier back home in New Jersey pondering "all that raw land that rolls in one unbelievable huge bulge over to the West Coast" and "all the people dreaming in the immensity of it" and the fact that "nobody knows what's going to happen to anybody besides the forlorn rags of growing old". And he thinks, as ever, of Dean Moriarty: "I even think of Old Dean Moriarty the father we never found, I think of Dean Moriarty."

So, too, does the overland crossing redeem itself, for life on the road affords endless oddball interactions with strangers: the Ambassador of Kindness, Maria the ticket-seller, Ace the trucker, even the well-meaning convenience store clerk in desolate Shelton. When I board the Greyhound again in Salt Lake City, part of me is glad to be back on the night bus, mixing with other scruffy travellers. I'll have to change in Reno, where the sun will rise on cheap motels and casinos, and before lunchtime the next day I'll catch my first glimpse of the Pacific, crossing the Bay Bridge into San Francisco. I'll soon be walking down Market Street towards the Castro district, the end of a long squiggly Beat journey that started in Manhattan. For now, I lean my head against the bus's tinted glass, dozing off as the lyrical lights flicker by, the continent humming beneath me like a madman.

The flight Emirates (www.emirates.com) flies from Dubai to New York with a direct return from San Francisco from Dh6,435 ($1,753) including taxes

The tour Denver's Beat Poetry Driving Tour can be found at www.denvergov.org/AboutDenver/today_driving_beat.asp

The book On the Road is published in paperback by Penguin