HOW do you write a follow-up to the book that changed your life?

For Graeme Macrae Burnet, it is by moving to the quiet after the storm. The Glasgow-based writer has had a year from a writer's dream. His second novel, His Bloody Project, was long listed then short listed for the Man Booker Prize. The experimental novel of a triple murder in the 19th century Highlands has since gone on to sell 160,000 copies in the UK alone, a success that has allowed Burnet to become a full-time writer.

His third novel, The Accident on the A35, is published at the end of this month. After the darkness of his last book, this is a return to the composed, provincial France of his first, The Disappearance of Adele Bedeau. Indeed, the book returns to the same border town, Saint Louis, and again features Inspector Georges Gorski, who takes centre stage.

The story begins straightforwardly: a provincial lawyer, Bertrand Barthelme, is killed when he crashes his car. Slowly, and elegantly, the story begins to unravel, prompted by Gorski's slightly half-hearted but honourable probing, and the actions of some of the town's residents, notably a trio of teenagers, including the lawyer's curious son.

Burnet is tall with a small quiff and a deep voice. We meet at the CCA in Glasgow over coffee. He admits he's slightly worried about the reception this novel will receive. It will inevitably be compared to his Booker success.

"I am a bit nervous," he says over a flat white. "The other books arrived quietly and at first no-one gave them any notice, but this one will get attention."

In the last 12 months Burnet's life has "completely transformed", he says. Born in Kilmarnock in 1967, Burnet has travelled the world since His Bloody Project sprung to unexpected prominence. Australia, Russia, New Zealand and elsewhere have left their stamps on his passport. "It's not even a burst," he says. "I am waiting for it to end, and it hasn't. Even being on the long list, never mind the short list, is massive. And the attention from foreign publishers is one of the biggest things, and that is one of the biggest legacies. It goes on. I have got 20 events between now and the end of November."

He acknowledges that his position is enviable. Burnet is now adjusting to a professional writer's life of writing and travelling and promoting, and arranging his timetable to make precious space for the solitary act of writing a novel.

Burnet is a believer, he says, in the craft of writing. Of working and honing, of rewriting and editing. He wrote a novel in the 1990s, and around 30 or 40 short stories. He started three or four novels before he began The Disappearance of Adele Bedeau, learning the craft. His inspirations, he says, include Georges Simonon and George Orwell, as well as Nicolas Freeling, the creator of the Dutch detective, Van der Valk.

Burnet has more writing to do: he is about to embark on another novel, and, after that, the final part of his French trilogy. "Luckily I can be a full-time writer now," he says. "So even with the pitiful amounts of money you make from a single copy ... I wasn't making a lot of money before, I am not suddenly going to start spending a lot of money, so as far as I am concerned the money I made from that book is so I can be a writer, and that is amazing."

The Accident on the A35 is an elegant, craftily written and frequently funny book. Burnet began writing it even before his debut was published and completed it before his life was turned upside down.

"I finished it two weeks before I was long listed for the Booker," he says. "So I had that in the bank, and of course once you get the attention of being in the Booker people are always coming up to you and saying, 'Well, no pressure for the next book.' But I had the skeleton of it there.

"The thing I discovered was that the writing process, for me, did not change in any way. Even when you are writing, and unpublished, you cannot think 'what will so-and-so think about this?', whether it is your mum or your husband or wife. I just had to make more of an effort to get back into that state. Once you are sitting there in front of the laptop, it is just as miserable and horrible as it always was."

Gorski is a crestfallen cop who endures minor humiliations, as well as a larger crisis, notably involving his estranged wife. This stolid, slightly perplexed character is not the average literary detective. He is a diffident sleuth, but slowly and surely he unravels the mystery of the dead man in the car. "The word that springs to mind for me is 'decent'," says his creator. "He is not wildly ambitious. I think the cop character in books is often very much an alpha male, but Gorski is very much not an alpha male. He is an ordinary man who happens to be a cop."

Saint Louis is real: Burnet has visited twice, once by accident, once to do more research. But it is exploration of these characters that he is primarily interested in, that and the psychological and physical morphology of a small town like Saint Louis. "I am not particularly interested in the cop stuff in the books," he says. "And often when I am editing I find myself writing in the margin: 'too coppy'.

"It is the human moments I am interested in, although of all my books it is the one that most resembles a conventional detective novel. It is the little human interactions."

Burnet says there will be only one more Saint Louis novel. "I am not interested in writing a long-running series. I think the difference in the conception of a trilogy is that there is some kind of unifying idea, it is a whole. But don't ask me how I'm going to do that yet."

Burnet first went to Saint Louis in Alsace by accident. While travelling through in 2001, he entered the local restaurant. "I went to this place for lunch, and I was completely captivated by it," he recalls. "People go for the menu du jour, they go every day, the builders go and the workers from the bank go, and they have a three-course meal and a bottle of beer or a glass of wine, and I love those places. You feel that everyone goes there, that everyone is there. I saw people there but to me they were characters in a fictional universe." A devoted fan of Simonon, Burnet felt he had walked into a scene from Maigret. He wrote down some notes and didn't look at them again for a decade. He has since returned to the town to familiarise himself with it again. "I walked the streets and went to the same restaurant again a couple of times – they must have thought 'who is this strange guy with his bad French?'"

Aptly, escape and restlessness are key themes in Burnet's novels to date.

"In a sense, Saint Louis to me is the first character of the book, and you cannot take the characters out of the setting. Manfred Baumann, in the first book, is trapped there. In His Bloody Project, Roddy [Macrae] would be very different if he was brought up in Glasgow. You realise that in all three books, the characters try to make an escape from their environment. That wasn't deliberate, but I have repeated that in all my books."

Does that sense of escape from restrictive surroundings come from the author? After growing up in Kilmarnock, he says as a teenager he "just wanted to get the f*** out of there". And he did: he lived in Prague in 1990 for a year a half, and spent time in Portugal, France and London, often teaching English to get by. Now, he is settled in his flat in the west of Glasgow, but for years it seemed he had wanderlust. "I think it's a healthy way of being when you are young – you want to go elsewhere. It feels constrictive. That's nothing against Kilmarnock in particular."

He thinks for a moment and adds: "In all my books, there this desire to escape. So, sure: I am always banging on about the death of the author and the futility in critiquing books in relation to the author's biography, but I can see in this case, it probably definitely is related to the fact that I wanted to get away – and I did."

The Accident on the A35 by Graeme Macrae Burnet is published by Saraband on Thursday, priced £12.99.