Andy Arnold is getting on his bike. Well, strictly speaking, the outgoing artistic director of the Arches is walking with it from one end of Argyle Street to the next. This most singular of visionaries is taking up the reins at the Tron Theatre. Arnold is about to give what he laughingly calls a "Churchillian" pep talk to his new staff, who have had an unsettled couple of years with the rapid-fire departure of two directors. Then it's back up the road to rehearse his final Arches production, Tom Murphy's Bailegangaire.

"We've always had a tradition of doing Irish plays at the Arches," Arnold observes, "so to finish with something that's bizarre and surreal is very fitting. It's a piece that, hopefully, should work perfectly in the Arches studio theatre. With these two women stuck in a room, it's plays like that and The Caretaker, where you become trapped in a room with them, that are perfect for the Arches."

Arnold's swansong also encapsulates a 17-year reign which has seen him regularly take off-kilter classics and present them in the charmingly roughshod vaulted theatre spaces. How this works in the Tron remains to be seen, though given Arnold's colourful back catalogue, it's likely that some of the Arches spirit will go with him. "It will be very strange," Arnold says of his move. "But I'm really looking forward to the challenge of trying to create the same atmosphere and energy of the Arches in a different environment. What we've achieved there will never be replicated, because we started it in 1990, and there's a great bond there with many people. But the Arches had a relationship with the Tron anyway, so, if anything, those ties will be stronger now. What I hope to bring here is a style of leadership based on a passion for what I do, exploiting the building to the full."

Just as the Arches was never supposed to be a theatre space, let alone a club and concert venue, Arnold never intended to become a theatre director. The original plan for the Southend-born maverick of Irish/Russian/Jewish descent was to earn a crust as a part-time teacher while quietly pursuing the life of a cartoonist and poet.

"There was this play I wanted to write," he says, "but I never got round to it. I did a social sciences course, and the first thing I did was join the drama society, but that was run by ex-public schoolboys, so I didn't want anything to do with it. My outlet then was the debating society and student politics. I've always enjoyed organising things, and I and a few mates thought about starting a free school."

Arnold's next inspiration came while teaching in Cambridgeshire, when he fell in with a man called Tony Grey. Grey, his brother and performance artist Bruce Lacy ran an eccentric theatre company called The Alberts, who, with Spike Milligan, had produced a show called The Best Of British Rubbish. Arnold was invited to Stratford East to see "a ridiculous show" by The Alberts called The Electric Element ("complete nihilistic nonsense") at the dawn of alternative theatre. He was smitten.

Arnold's first sojourn into performance was with a lifesize puppet show called R C Skidmark - Life On The 20th Floor, and he worked as a community artist in Yorkshire after chucking in teaching after a year to publish punk poems in New Wave News.

"I went to Yorkshire Television with an idea for a children's show called Yorkshire Pudding," Arnold remembers. "It was a bit like Tiswas, but more educational. But then the job as artistic director of Theatre Workshop came up."

Arnold's new post, which he took up in 1980, was essentially as a community arts worker. He moved into directing, with his first production being a play by disabled writer Tom Lannan called The Year Of The Cabbage. This ushered in a golden age of Theatre Workshop.

"What I did over the first year was bring in people and empower them to do what they wanted to do. Until then, all the decisions had been made by the artistic director, but as long as people felt they were getting support and we were all going in the right direction, it created this wonderful energy.

"Obviously you have to have a vision of what you want, but it's important to give people the freedom to explore what they want to do. Within that atmosphere other great ideas come out of it. That's how the Arches ended up doing club nights. Any other building would ask for a business plan, but we thought, if it's a good idea, let's run with it."

After five years at Theatre Workshop, Arnold worked at the Mandela Theatre, situated in the Gateway Exchange, a centre offering opportunities to rehabilitated drug addicts set up by Jimmy Boyle. Arnold directed an adaptation of Boyle's prison memoir at the Royal Lyceum and worked in prisons. A restaging of Boyle's The Nutcracker Suite was followed by Barrie Keefe's Gotcha. This was followed by an unlikely tenure at London's Bloomsbury Theatre.

During Glasgow's 1990 turn as European City of Culture, Arnold was making street theatre for the Glasgow's Glasgow exhibition in what was then dilapidated railway premises. When the show ended, Arnold pleaded with the council to give him the keys to the building, and put together a cabaret version of Glasgow poetry anthology Noise and Smoky Breath, for Mayfest 1991. The Arches had arrived, and what started off as a small theatre company soon became swamped by clubs, gigs and site-specific happenings that took full advantage of the building's dank expanse.

Seventeen years on, and with the Arches a major player on Glasgow's theatre scene, Arnold's credentials are rooted in an alternative ethos.

"I'm glad I never trained in theatre," Arnold says proudly. "Everything's happened by chance, and I feel so lucky to be doing it. Because of that, I want to push things to the max. Even today at the Arches we just ignore all the rules of doing theatre. It started with poor theatre because we had no money, and we've continued doing it that way.

"The thing that I learned from The Alberts, and which will stay with me forever, is the anarchy of theatre. Theatre should always be something slightly decadent and slightly smelly. It should be offensive. I still believe in that. I wore a leather jacket, jeans and Doc Martens when I started, and that's what I still wear now. It's punk putting two fingers up to what theatre's supposed to be about. I'm too old to change now."

Bailegangaire (The Town Without Laughter), the Arches, Glasgow, February 26-March 8.