Four months into his residency at a studio on Rickmansworth High Street, artist Ross Ashmore has left his mark. Glutinous strands of paint have collected along the shelf where he works like candy-coloured drips of candle wax. Using the impasto technique of luxuriously thick layers of oil paint, Ross builds three-dimensional works that are quite in keeping with his architectural subjects.

His current show, Going Underground, at the Watersmeet Theatre’s Artistsmeet Gallery, marks the latest stage in his three-year project to paint all of the London Transport Underground Stations – of which there are 270. He started just over a year ago and has so far rendered 100 destinations. He started at Zone 1.

“I’m working zone by zone,“ says Ross. “It gives me structure otherwise you’d find yourself cherry-picking stations. Actually, the ones you might ignore are often the most interesting.“

Each image is unique due to its location – you realise a lot of Tube stations were built on corners to give passengers maximum access, others have distinctive features such as the Victorian baked clay tiles found at Covent Garden, Holloway Road, Oxford Street and Russell Square. At Hyde Park Corner, the view is dominated by Marble Arch and the station has receded into the background. Similarly Westminster Tube is overshadowed by the majestic statue of Boudicca.

Ross captured Arsenal on match day with a sea of red shirts spilling out towards the road and a policeman on horseback in the foreground.

“I’ve tried to put people in the pictures without being too specific about individuals. Some people stood and watched me, so I’ve painted them in close-up, while others passed by glued to their mobile phones,“ says Ross.

“The concept of going underground is really quite an amazing thing. When you’re on the Tube, it’s all transitory. You get snatched views or glimpses of things and you’re all in this small, intrusive space together. It makes you wonder how much people observe.“

After studying fine art and graphics at Bristol College of Art, Ross worked as a graphic designer for 20 years before deciding to paint full-time. A father of three grown-up children, Ross also finds time to take life drawing classes in the Frobisher Studio at Bushey Museum. He tells me he might accomplish 35 sketches and six big pictures in an afternoon.

Glancing at a few examples, I can see even his briefest line drawing is technically excellent, but Ross is not one to boast. Working in isolation has made him very self-effacing. He is fully absorbed in his work. Ross says an early inspiration for the current project came from a Doctor Who episode titled Yetties in the Underground.

Growing up in Buckinghamshire, he was used to hearing the clack of trains along the Metropolitan Line.

“I’ve always heard the sound of trains from where I’ve lived – from the back garden in Amersham and when I moved from Little Chalfont to Rickmansworth in 2008, there were the London red buses through the High Street, London cabs and Tube trains, so I’ve always felt connected.“

Ross feels there’s a buzz about Rickmansworth and he’s very happy to be exhibiting his work at the theatre, just a few minutes’ walk from where he wields his brush. He wants art to be in the public eye.

“The Watersmeet is one of the best places for art to be rather than it being shut away in galleries. It’s a visual communication in the same sense as poetry is a verbal one, only mine is interpreted in paint. It should be something people can respond to.

"I want to put feeling and emotion in my work and for people to see the marks. I want to involve them, for me the image is less important than the process.“

Ross Ashmore’s Going Underground is at The Watersmeet Theatre, High Street, Rickmansworth until Friday, March 2.