The Government must make some tough decisions if it wants to avoid severe traffic congestion by 2041.

Road capacity will have to be massively increased whether or not national road pricing is introduced, says a new RAC Foundation report, Roads and Reality, which is published today (Wednesday).

It concludes that by 2041, car ownership will be 44% higher than today, while car traffic will increase by 37%.

As a result the report says that, with or without road pricing, Britain needs investment in roads at an annual rate of about 400 lane-miles – equivalent to the average level of road building achieved annually in the 1990s.

However, the report does not recommend abandoning road pricing, arguing instead that the best balance of economic benefit will be secured if road building is combined with efficient pricing.

“As additional strategic road capacity is added, flows on the main roads increase and journey times will fall.

"Building an extra 400 lane-miles every year between 2010 and 2041 would yield substantial benefits in journey times and reliability,” it said.

“Efficient pricing on its own would provide for only 85% of forecast growth in traffic on strategic roads.

"Pricing without road-building will just drive poorer people off the roads.”

David Holmes, chairman of the RAC Foundation, said: “Our children and grandchildren will not accept poorer standards of service from transport than we have today. This report shows how we can meet the needs of people for mobility and access, while also protecting the environment.”