OFF-ROAD drivers could be banned from the North Yorks Moors and North Yorkshire Dales under proposals aimed at protecting the environment.

Concern about the extent of damage to some of England's most scenic countryside caused by four-wheel drive vehicles using unsurfaced "green" lanes has prompted consideration of a blanket ban to stop them entering areas under threat.

A forum representing rural interests, including the two national parks, is now looking at introducing restricted zones, which could cover entire swathes of the countryside.

The proposal would replace the existing system where separate traffic orders have to be introduced for each route, a costly and time-consuming process which in practice means restrictions are hard to achieve.

A spokeswoman for the Department of Environment, Transport and the Regions said the possibility of introducing restricted zones came after a meeting between environment minister Michael Meacher and national park representatives earlier this year.

She said the Countryside Measures Traffic Group, which is overseen by the DETR, is now looking at the practical difficulties of introducing restricted zones.

Steve Macare, chairman of the Yorkshire Dales National Park Authority, welcomed the proposed zones and said: "I would like to see them cover the whole park.

"At the moment there has to be traffic orders on each one and they are always challenged, so it takes an awful long time to get them through and there would be signs everywhere.

"Whereas if an area or a zone is designated we would be able to do it en bloc and we would only need signs at the entrances."

David Brewster, head of park services for the North York Moors National Park, said off-road vehicles caused considerable damage to the park's heather moorland.

He said: "The original route becomes very badly rutted and the result is people then divert from that, causing further damage.

"There are some stretches that are approaching the width of a dual carriageway because people keep avoiding the worst areas and that means the loss of heather moorland."

He said the park had proposed that traffic restrictions should automatically apply to green lanes, so there is a presumption against their recreational use by four-wheel drive vehicles.