The Highways Agency has confirmed that the hard shoulders on six of Britain's motorways will be opened up to traffic in a bid to reduce congestion.

More than 100 miles of hard shoulders on roads including the M25, M1, M60, M62, M3 and M6 are to be used as an extra lane, the agency confirmed.

Under the new project, titled "managed motorways", the distance of some roadside refuges are to be doubled. They are currently between 800m and 1,000m apart.

Other changes, which are to be rolled out next year, would see the removal of overhead gantries informing drivers of variable speed limits. They will be replaced with signs, which only cover the nearside lanes.

A Highways Agency spokesman said: "The existing managed motorways schemes have not only improved reliability and eased congestion, but have also delivered significant safety benefits.

"Evidence from the M42 managed motorway scheme shows that personal injury accidents have more than halved, and there have been no fatalities in the five years it's been in operation as a result of variable speed limits and hard shoulder running.

"Through experience of operating the M42 and M6 schemes, we have produced proposals where the hard shoulder is converted to a running lane on a permanent basis and less infrastructure is needed on the existing route of future managed motorway schemes.

"We are working with road user organisations to develop the detail for these proposals.

"We are confident that once these proposals are fully developed they will provide the additional capacity required, without compromising overall safety."