It’s not the kind of role that Samuel L Jackson usually gets offered. Over the years, the multi-nominated actor has played everyday heroes and far-from-everyday superheroes, charismatic criminals and philosophical drop-outs. Later this summer, he will be sorting things out in a galaxy far, far away in the second Star Wars prequel, Attack of the Clones.

But a few weeks ago in the US, Jackson hit the screen in one of the most unusual parts he has ever played: that of Doyle Gipson in Changing Lanes. Gipson - even the name says ‘nondescript’ - is the exact opposite of the roles Jackson usually plays: unusual precisely because Gipson is a very, very ordinary man. Until something snaps.

“Sam is obviously a wonderful, wonderful actor,” says Changing Lanes’ director, Roger Michell. “A lot of his films, like Shaft, Jackie Brown or Pulp Fiction, portray him as very hip and very cool, but this is an uncool role. I mean, this guy Doyle isn’t hip: he’s the reverse of hip. He’s awkward and clumsy. He’s a guy who just doesn’t fit in.”

Jackson agrees. “Doyle is the anonymous one we pass on the street and pay no attention to,” he says. “He’s got the nondescript suit, the ordinary haircut and the regular glasses. He’s an everyday Joe whose life is suddenly changed by something outside his control. I figured it would be interesting to explore that, because I don’t run into that kind of guy that often.” The guy Jackson does run into, quite literally, in his Gipson persona, is Ben Affleck’s Gavin Banek. Set over a limited, 36-hour time-frame, on and around Good Friday, Changing Lanes also has a very ordinary starting point: a minor traffic accident. Both stressed and late for appointments, Gipson and Banek run into one another during the morning rush hour on FDR Drive in New York City.

It is one of those moments - like the one that happened to Michael Douglas at the start of Falling Down - when something snaps. Everyone has given in at some stage in their lives to road rage, even if giving in amounts to no more than a rude gesture or a muttered curse. But, for Banek and Gipson, it goes much, much further.

“The script immediately captured my imagination,” says Michell. “It’s about a chance meeting between two men that spins them out of their orbits, causing them to behave in irrational, strange and violent ways. You just don’t expect the steps these guys will take to get at each other.”

ROAD WARRIORS Samuel L Jackson (top) and Ben Affleck go to war over a minor fender-bender in rush- hour traffic.

Affleck - who first read the screenplay sitting on the deck of an aircraft carrier while filming Pearl Harbor - had much the same reactions as both Jackson and Michell: it was something he hadn’t been asked to do before; and it was a gripping account of how the reaction to a small incident can escalate out of control.

“It struck me as honest in the way that it detailed how people fall apart,” he says. “What was especially appealing was that it’s different from what I’ve done before. It isn’t about some grand event; it isn’t of historical or political importance; and it isn’t an epic tale. But it is a very personal story of two men coming unravelled. I felt it would afford me the chance to do the kind of acting that I haven’t had the opportunity to do until now.

“A script like this makes you work harder and demands more thought,” he adds. “You’re required to think a little bit more about your own experiences and the emotional weight that you bring to a project. I think it makes me a better actor to continually challenge and push myself, and Roger Michell has been so helpful. Without him, my performance wouldn’t have been half of what it is. He’s been a wonderful gift to this film.”

The script that made such an impression on Affleck is a first-time effort from Chap Taylor, working with Oscar-nominated screenwriter Michael Tolkin (The Player), and it was just the thing that Michell - the British director of Notting Hill - was looking for as his first US film.

But Michell may not have spotted at least one of the production requirements that was built into it. Although the film’s main set was built inside an abandoned armoury in Brooklyn, the incident that triggered it absolutely had to be filmed in heavy New York traffic: a few cars and the odd bus trying to look busy on a studio backlot simply would not have done.

Finally, after weeks of negotiation, Changing Lanes became the first production ever to shut down traffic completely on FDR Drive. Obviously this could only be done on a Sunday, so the whole schedule was redesigned accordingly, with the company’s week running from Wednesday to Sunday.