Motorist will spend more than 139,000 hours a year stuck in traffic on the A27 north of Brighton by 2025 if road pricing is not introduced.

That is the prediction of the Department for Transport after the publication last week of the Eddington report, which suggested drivers should be charged varying prices from 2p to £1.34 to use roads depending on the time and day of travel.

According to the DfT, the A27 north of Brighton, where it meets the A23, is the most congested road in Sussex.

The Highways Agency said that stretch currently had an annual average daily traffic flow of 78,000 vehicles, which would only get worse if something was not done now.

Sussex Enterprise has been calling for road pricing for ten years but says it will not work until the Government provides alternatives for motorists to get from A to B.

Mark Froud, chief executive of Sussex Enterprise, said: "Our estimate is congestion in Sussex costs businesses and organisations £1.2 billion a year.

"It is intensely frustrating and incredibly costly but the impact of congestion also affects the environment.

"Driving five to ten miles per hour is the speed that produces the maximum amount of pollution.

"For these reasons we have always supported the idea of road pricing. It will take between ten and 15 years to introduce but it could work.

"But the Government has to spend lots of money on the transport infrastructure and it needs to start now.

"Build a new railway from the South Coast to London and look at ideas to double capacity."

Mr Froud said other hotspots in Sussex included the A27 around the Beddingham rail crossing, Handcross Hill on the A23 and all roads surrounding the major towns.

The DfT mentioned six other major roads in Sussex - parts of the M23, A21, A259, A264, A22 and the A27 between Lewes and Eastbourne.

By 2025, drivers could waste between 28,000 and 139,350 hours a year sitting in jams on these roads.

With road pricing, the number of hours lost could be reduced to under 28,000.

Friends of the Earth said stop-go traffic was not good for the environment because of the amount of pollution caused.

Spokesman Neil Verlander said: "Carbon dioxide emissions are rising.

"Congestion charging is not the magic bullet and any road-charging scheme needs to tackle climate change too.

"That is the way forward.

We need to have fewer cars on the roads rather than just shifting them around at different times.

"At the moment, you pay depending on how much fuel your car uses.

"That should be increased so people who drive less fuel-efficient cars pay more and drivers of "green" cars pay less.

"We need a big investment in public transport to make it affordable, safe, convenient and not overcrowded so it is more attractive to drivers.

"At the moment the system does not suit anyone."

Councillor Matthew Lock, East Sussex County Council's lead member for transport and environment, said: "The council is concerned about the limitations of our road and rail networks.

"The council will consider the research on road-user charging and whether it could be applied to selected routes.

"One of the key factors to consider is the impact it would have on the rest of the road network and on economic regeneration initiatives in East Sussex."