THE M4 motorway celebrates its 30th anniversary today.

On December 22, 1971, a 50-mile section between Swindon and Maidenhead was opened, which transformed road travel between South Wales, Bristol and London.

The opening of the M4 spelled the end of long journeys to London using the A4, through towns such as Marlborough, Calne and Bath.

The M4 carries now 160,000 vehicles a day at the London end and 117,000 at Bristol. Plans are underway for major improvements at the M4/A34 at junction 13 at Chieveley.

Improvements are also being planned to the route of the A33 and its connection to the motorway, and drivers should be able to plan their journeys better with more information through message signs.

In addition, the Government is studying improvements on both the road and rail corridors from London to Wales and the South West.

The M4 is now widely acclaimed as being one of the major contributing factors to the economic prosperity of the M4 corridor, coined Silicon Valley.

It has changed irrevocably the economic landscape for towns on its path west, including Swindon with its many blue chip technology industries.

Bill Wadrup, the Highways Agency's divisional director for the south east, said: "The M4 has cut journey times between London and the west, improving communication and continuing to generate economic prosperity in the region.

"Some of the most successful towns and fastest growing industries in the UK are to be found along its route.

"Companies moved to the M4 corridor, despite its high cost base, because with the M4 they are an aeroplane's ride away from wealth creation. Heathrow is the gateway to the world's economy and the M4 provides a gateway to that wealth.

"This is the anniversary of a tremendous achievement by the engineers who contributed to such a massive piece of infrastructure."

The 50-mile stretch was opened by the then Parliamentary Under Secretary of State for Transport, Michael Heseltine.