The series follows the lives and adventures of five racing vehicles, Roary, Maxi, Cici (Zizzy in the US), Drifter (Dragga in the US), Tin Top, and the people who they work for, Big Chris the Mechanic, Marsha the Race Marshall and the owner of the racetrack, Mr. Carburettor.

Every story begins and ends with some brief narration normally from racing car driver Sir Stirling Moss, who is also used as a voiceover.

The US version is narrated by American stock car driver Sam Hornish Jr. Roary the Racing Car uses a combination of computer-generated imagery and stop motion animation; the stop motion animation was initially provided by Cosgrove Hall Films, the producer of Noddy's Toyland Adventures, Engie Benjy, Little Robots, Fetch the Vet, the third to sixth Postman Pat series, Pocoyo, the original 1981 Danger Mouse series, Count Duckula, The Wind in the Willows and many other shows produced by this company, and latterly by Chapman Entertainment's own in-house studio, along with its sister show Fifi and the Flowertots.

The series was created by David Jenkins, who spent four years working in senior management at Brands Hatch Race Circuit.

It was designed and developed by Keith Chapman, creative director of Chapman Entertainment and the creator of Bob the Builder (both 1999 and the 2015 reboot series), Fifi and the Flowertots, and later, Paw Patrol and Mighty Express, and the series' executive producer is Greg Lynn.