The countryside around Midland motorways and major roads is being "scarred" by scores of advertising hoardings that seldom have planning permission, according to environmental campaigners.
The Campaign to Protect Rural England today publishes a survey of the major road network of England which reveals there are 900 hoardings - advertising everything from Kentucky Fried Chicken to caravan dealerships across the country - one for every three miles of major fast road.
The survey found the M6 in Staffordshire boasts 20 hoardings along a ten-mile stretch, meaning a 60mph motorists would see one every 30 seconds.
CPRE believe the majority of advertising on trailers, often over 10 ft tall, is illegal and is "defacing the countryside and reducing safety".
Paul Milner, CPRE planning campaigner, said most of these hoardings are set up without planning consent - and the few that have should never have been granted it in the first place.
"For more than 50 years, planning controls have saved the English landscape from the pox of outdoor advertising.
"This achievement is now in danger.
"Billboards and hoardings are mushrooming alongside motorways and major roads across England, despite Government policy and regulations clearly stating they should be strictly controlled."
CPRE also investigated the perpetrators of what they call "this outrage".
One firm's website claims "by being completely mobile we have the flexibility to put your advertisement where planning permission would not normally be granted".
Mr Milner added: "We don't have to put up with this flagrant abuse of planning rules... we need a proper legal duty to enforce planning control.
"Without this, the rash of roadside advertising will just keep coming back."
He said CPRE welcomed Government guidelines for local authorities to use their powers to take action.
"But it is not enough on its own," he said. CPRE has published its own guidelines for local planners, showing how they can learn from other local government colleagues in different areas that have been tough with roadside advertising.
The Outdoor Advertising Association (OAA) has publicly distanced itself from motorway advertising, but major fast food and supermarket companies still feature on mobile roadside adverts.
Alan James, chief executive of the OAA agrees with the CPRE stance.
"There are no grey areas to this, these roadside hoardings are illegal.
"Just in the same way as someone needs planning permission for a house extension, you need the same for an advertising hoarding.
"It happens, I think, because the practitioners know they won't get planning permission but believe local authorities do not have the resources or manpower to stop it happening illegally."