The articulated buses will be tried out along the Shepherds Bush to Uxbridge route from next week.

The Mayor of London, Ken Livingstone, said the vehicles would reduce overcrowding and improve the overall service for passengers.

Mr Livingstone said the buses would become a common sight in London if the trial proves successful.

'Boost capacity'

At 40 feet (18metres) in length the buses are nearly twice as long as current vehicles.

Transport for London said they will provide greater comfort for travellers particularly passengers with mobility difficulties.

Peter Hendy said: "In the short-term buses offer the only answer to the capital's transport problems.

"The trial will provide us with valuable hands-on experience of operating articulated buses on busy London routes."

A fleet of six articulated buses will be running along route 207 from next Monday until early 2002.

There are already plans to introduce the buses along the Red Arrow Route network from Waterloo to London Bridge, from spring next year.

Mr Livingstone said: "The trial of articulated buses on London's streets is an innovative step to further improve bus services in the capital.

"With demand for bus travel rising, these articulated buses offer us an effective means to boost capacity on routes and give greater accessibility.

"If they are a success these buses could soon become a common sight around the city.