The long wait has only heightened the expectations of a project that will run the risk of disappointing the millions of Kerouac disciples for whom the book, published in 1957, was a near-sacred text of rebellious self-discovery and literary exuberance.
Taking the cinematic risk is Francis Ford Coppola. His production company, American Zoetrope, has owned the rights to On the Road since 1979. After several false starts, he appears finally to have given the film the green light, with casting and pre-production to begin early next year.
The book is a thinly disguised autobiographical account of Kerouac's boozy hitch-hiking adventures across the US and Mexico in the early 1950s. It is narrated by his alter-ego, Sal Paradise, who travels with his womanising and irrepressible best friend, Dean Moriarty, in real life Neal Cassady.
Excitement about the film is growing with Coppola's final choice of director and writer. Respectively, they are Walter Salles and Jose Rivera, who together created another road movie that met with considerable critical success, The Motorcycle Diaries (2004). That chronicled the journey of a young Ernesto "Che" Guevara through South America, also in the 1950s, before he became the leftist revolutionary icon of Cuba. The Mexican star Gael Garcia Bernal played Guevara.
The hope of Coppola and his new team is that On the Road will become a road movie as important to cinema as the novel was to American literature. But no one says it will be easy.
"The book is inherently difficult to adapt to the screen, and we've never quite found the right combination of director and writer to do it justice until now," Coppola, the director of Apocalypse Now, told The Hollywood Reporter. As Kerouac fans know, he helped start the "stream of consciousness" school of writing, which makes for astonishing word flourishes but often pays little or no heed to traditional narrative structures or even plot-lines. It was a style that was also called "spontaneous prose" by critics at the time.
David Brinkley, the well-known Kerouac scholar, said: "If you read On the Road it's a valentine to the United States ... pure poetry for almost a boy's love for his country that's just gushing in its adjectives and descriptions" On the Road which became one of the world's biggest sellers and is translated today into 47 languages, follows Paradise as he hitches rides with strangers in cars, rides in the empty freight carriages of trains with American hobos, forges fleeting friendships and struggles with fraught feelings of doubt and loneliness.
As Paradise, Kerouac wrote: "The only people for me are the mad ones, the ones who are mad to live with, mad to talk, mad to be saved, desirous of everything at the same time, the ones who never yawn or say a commonplace thing, but burn, burn, burn like fabulous yellow roman candles exploding like spiders across the stars and then in the middle you see the blue centrelight pop and everybody goes 'AWWW!'"
Only three years ago, it appeared Coppola had at last hired the US writer Russell Banks, author of the Sweet Thereafter, to write the Kerouac script. Banks went so far as to announce his new task while visiting the Edinburgh Festival in 2002, but the agreement with Coppola fell through. At the time, Coppola had also provisionally engaged Joel Schumacher to direct the film. It was said at the time that Brad Pitt might play Paradise.
The rumour now is that the lead role will go instead to the stage and film actor Billy Crudup. There is no word of the possible involvement of Pitt, but there has been speculation that the part of Moriarty could go to the Irish actor Colin Farrell. Despite its history as a road movie project that never seems able to hit the hard-top, Zoetrope says this time the project really is a certainty. "There have been several scripts over the years but this looks like it," insisted Kathleen Talbert, a spokesman for Coppola, who originally had it in mind to shoot the film on 16mm film in black and white. Coppola's own portfolio of movies also includes 1974's The Godfather Part II and American Graffiti (1973).
Others in Kerouac's entourage of West Coast, counter-culture friends included Allen Ginsberg, the poet of Howl fame, and William S Burroughs, the author, both of whom appear in the book respectively as Carlo Marx and Old Bull Lee.
Born in 1922, Kerouac died from alcoholism in 1969. He was married by then to Stella Sampas and they lived in St Petersburg Florida, to be close to Kerouac's mother, Gabrielle. He was famous among friends for being able to drink as many as 17 straight shots of whiskey in just one hour. The autopsy said the cause of death was cyrrhosis of the liver.
By then he was the undisputed figurehead and prophet of the American Beat Generation, but always a reluctant one. He was 47 when he died and had just $91 in his pocket. "He never wanted to be part of a cultural movement," Garry Snyder, a poet who shared his home with Kerouac, said. "He wanted to be a writer".
Not that Kerouac was unaware of the critical peaks he had already reached as a writer. A former girlfriend, who met him through a blind date organised by Ginsberg just nine months before the release of On the Road, said on the day of publication he did not have the money in his pocket to buy even a bus ticket to New York.
When The New York Times reviewed the work and compared Kerouac to Ernest Hemingway, he was overwhelmed. "Jack went to bed obscure and woke up famous," the girlfriend, Joyce Johnson, said.
Indeed, a second film biopic about Kerouac may soon also in be production, based on a memoir written by Johnson and her years with Kerouac entitled Minor Characters. She may be played by Scarlett Johannson or Chloe Sevigny, Hollywood sources say. If anyone says the moment has passed to make a film of the book, Salles, 49, who is from Braz-il, will strongly disagree. He said: "On the Road is a seminal book that gave voice to a whole generation, capturing its hunger for experience, unwillingness to accept imposed truths and dissatisfaction with the status quo. It is as modern today as it was four decades ago."
Kerouac famously wrote the book on a single scroll of paper 120ft long fed into his typewriter. Fans imagined it poured out of him in one white-hot eruption of inspiration, but in truth he is said to have toiled over the words for as long as any other writer. Some have compared his time at the typewriter to the toils of a jazz musician composing music that is full inspiration but crafted with meticulous care.
"Whatever you feel, that's the way jazz musicians do it," Mr Brinkley said. "What [he] also knew was that ... people such as Charlie Parker and Dizzy Gillespie were skilled, crafted musicians. This didn't just come out of a whim."
Other books written by Kerouac include Big Sur, The Dharma Bums, The Subterraneans, Dr Sax, Mexico City Blues and Tristessa. The original manuscript of On the Road went for auction in 2001 and fetched an astonishing $2.4m (£1,600,000), providing fresh testament to Kerouac's status as an icon. The buyer was Jack Irsay, a prominent American football team owner. There is a Jack Kerouac school of creative writing in Orlando, Florida, where he lived as a young man. This year, Massachusetts declared that 12 March would be "Jack Kerouac Day" in the state.
He was born in Lowell, Massachusetts, as Jean-Louis Lebris de Kerouac to parents from French-speaking Quebec in Canada. He began speaking English only when he attended school aged six. After shining in high school as an American football quarterback, he landed a reporting job on the Lowell Sun newspaper, his first brush with writing for a living.
A section of the film will be shot in San Francisco, which Paradise, on his approach into it, describes as "the fabulous white city on her 11 mystic hills with the blue Pacific and its advancing wall of potato-patch fog beyond, and smoke and goldenness in the late afternoon of time".
Die-hard fans of Kerouac can only now keep their fingers crossed that the book they love so much does not become mangled on its journey, at last, to the big screen. For some, the fear of sacrilege may be too much. Kerouac once said: "Offer them what they secretly want and they, of course, immediately become panic-stricken."
The roll-call of road movies
EASY RIDER (1969)
This was a tale of the search for freedom in conformist and corrupt America gripped by paranoia, bigotry, violence and Vietnam protest. The odyssey of two bikers reflected the collapse of the idealism of the 1960s.
VANISHING POINT (1971)
Part art film, this is one man's existential high-speed drive across the stunning scenery of America's West, chased by the law and guided by a blind disc jockey. It is, in part, a social commentary on the changing mood of America, to a rock soundtrack.
It is based on the real-life murder spree of Charles Starkweather and his girlfriend, Caril Ann Fugate, in 1958. Kit Carruthers and girlfriend Holly Sargis from Fort Dupree, South Dakota, are on the run after killing Holly's father. They cross the Dakota Badlands leaving a trail of random murders. On the surface it's just another rural-gangster movie, but the film is distinguished by Martin Sheen's superb performance, Sissy Spacek's artless narration, Malick's masterful composition, and Tak Fujimoto's poetic cinematography.
THELMA AND LOUISE (1991)
Ridley Scott's film starred Geena Davis and Susan Sarandon, who hit the road, take a wrong turn, and the law gives chase. Thelma and Louise transformed the waitress and the housewife from victims of circumstance into icons of feminism.
MOTORCYCLE DIARIES (2004)
The journey of self-discovery across Latin-America by the young Ernesto 'Che' Guevara, with his best friend, Alberto Granado. The film by Brazilian director Walter Salles is part buddy movie, part social commentary.Reuse content