British pop stalwart Rod Stewart has spent decades laying down tracks of a different kind thanks to a little-known lifelong hobby -- building model railways.

The gravel-voiced singer has spent the past 23 years creating an imaginary American city and railway in his Los Angeles mansion.

He opened up about his "addictive" hobby to "Railway Modeller", bagging the cover page of the British hobbyist magazine's December issue.

"When I take on something creative like this, I have to give it 110 percent," Stewart told the publication in an exclusive interview.

"If I'd have realised at the start it would have taken so long, I'd have probably said 'No!'"

The father-of-eight -- whose hits include "Maggie May", "You Wear It Well" and his cover of "Downtown Train" -- said he began his latest project soon after he built his LA home in the early 1990s.

He earmarked the attic for his intricate cityscape, which he named "Grand Street and Three Rivers City".

It features skyscrapers, warehouses and hills, alongside railway infrastructure like tracks, stations, tunnels and bridges.

"I don't like to see flat backdrops, they spoil the illusion, so I went for more buildings and streets than tracks. Just to give it a great depth," he said.

The roots of Stewart's hobby date back to his childhood in Britain, and a family holiday aged eight to Bognor Regis on the English south coast.

The ageing rocker recalled seeing a model railway shop's window display and thinking "if only I could get paid to build a model railway like that".

Rod Stewart built an intricate cityscape, which he named 'Grand Street and Three Rivers City'
Rod Stewart built an intricate cityscape, which he named 'Grand Street and Three Rivers City' AFP / Andy BUCHANAN

But Stewart, who grew up in Archway, north London, opposite busy railway tracks, did not have enough room in the family home for a model train set.

Only by the mid-1960s and his late teens, when the family had moved to a new house, was he finally able to go full steam ahead with the pastime.

"I got my own bedroom and built a layout all around the perimeter walls. Even across the window," Stewart said.

Fast-forward three decades and he had become an international star, but he had not lost his enthusiasm for replica train sets.

Now living in the United States, he decided to embark on his most ambitious layout yet based on American scenery, becoming a regular customer at two shops selling model railroads in Los Angeles.

The music icon acknowledged he was so hooked that he would keep working while on the road touring -- even booking an extra room in hotels to serve as his model-making workshop.

The 74-year-old, who revealed earlier this year he has been given the all-clear after developing prostate cancer, added he was more of a landscape artist than a train geek.

"I can't tell a Niagara from a Hudson," Stewart said, referencing well-known US locomotives.

"It's the landscape I like. Attention to detail, extreme detail, is paramount. There shouldn't be any unsightly gaps, or pavements that are too clean."

Stewart is not the only celebrity to have revealed a passion for model railways.

Entrepreneur and film director Walt Disney, singer-songwriter Neil Young, crooner Frank Sinatra and "The Who" frontman Roger Daltrey are all said to have been fellow enthusiasts.

Daltrey was quoted by music publication the NME in 2014: "The great thing about model railways is you can be doing a bit of woodwork, a bit of painting, a bit of this, a bit of that, and having fun with your mates and you can listen to the radio."