Bathing beauties, Britain 1926 (in colour for the first time)

One of the most remarkable documentary films ever made, featuring historic scenes shot along the length of Britain, is to be shown to a mass audience for the first time.

The Open Road is a record of a journey from Land's End to John O'Groats by Claude Friese-Greene, the son of cinema pioneer William. Claude made the film to show off his revolutionary colour process but, because of its technical complexity, his invention never caught on.

As a result, this three-hour social travelogue, made between 1924 and 1926, showing bathing beauties in Plymouth, Welsh miners, the Blackpool illuminations and tartan-makers in Kilbarchan, Scotland, was never shown commercially.

In it, Friese-Greene, a young survivor of the Somme, toured the country in his Vauxhall D-type, with his assistant, shooting scenes of everyday, mainly rural, life. And when a scene lacked a certain decorative quality that the young film-maker wanted, he would ask local girls to walk coquettishly through the shot.

The film, whose new colour process required projectors to be run at a faster speed than normal, was used only in fragments at trade shows. Friese-Greene went on to work as a cinematographer with directors such as Alfred Hitchcock. He died aged 45 in 1943. His family gave a version of the film to the British Film Institute.

Now it has been restored and the BBC will broadcast parts in The Lost World of Friese-Greene, a series of three programmes that starts on 18 April on BBC 2.

Additional reporting by Julia White