The rise in charges will come into effect from 1 January 2007

Tom Fanning, chief executive of Midland Expressway Limited, said the toll road had taken traffic off the M6 which he said would continue.

Car drivers will pay �4, up from the current �3.50, and lorry drivers �8, up from �7, from 1 January 2007.

But anti-toll campaigners said the rise would mean more congestion.

"We have seen quite a bit of growth in 2006. Drivers continue to utilise the M6 Toll more and more," Mr Fanning said.

Drivers are avoiding using the toll road because of the cost John McGoldrick National Alliance Against Tolls

"They are realising what a reliable journey it is and they can avoid the congestion on the M6. I believe we will continue to see increases in levels of traffic using the M6 Toll."

The latest figures show that the average number of vehicles using the road throughout the day in September was 55,500, an increase of 19,000, or just over 50%, on the 36,700 vehicles in January 2006.

However, the traffic flow from September 2005 to January 2006 fell by just over 20% from just over 46,000 vehicles-a-day.

But John McGoldrick, co-ordinator of the National Alliance Against Tolls, said: "This is a move in the wrong direction in congestion terms.

"Drivers are avoiding using the toll road because of the cost and the M6 is almost as bad as it was before the road opened.

"There is so little traffic using the toll road relative to the M6. It's a crazy situation.

"It would make sense if you've got a road to use it to its full extent. The time wasted and delays will continue to harm business," he said.