One thousand miles of major road routes will become gridlocked unless new capacity is created, a report has warned.
Roads that are most at risk from severe congestion are predictably the already busy London orbital road, the M25, and areas around Birmingham, Liverpool and Manchester.
The RAC Foundation report ‘Roads and Reality’ says new road capacity will be essential whether or not national road pricing is introduced.
The study says road users are the only energy users currently paying the full cost of their carbon emissions; and that cars will continue to get greener and cleaner towards 2050.
It also concludes that by 2041, car ownership will be 44% higher, while car traffic will increase by 37%.
The analysis shows that, with or without road pricing, Britain needs investment in roads at an annual rate of about 600 Lane Kilometres - around the average level of road building achieved in the 1990s.
Extra capacity combined with fair and efficient pricing would be fairer as it would reduce the price to road users, and travel by car would be affordable for more people on low incomes, the report adds.
One of the report's authors, Professor Stephen Glaister of Imperial College, said: ‘The modelling suggests that the Government cannot use the possible future introduction of road pricing as a reason to ignore the need to improve the strategic road network.
‘If national road pricing has been put on the back-burner, more urgency is required for intelligent investment decisions now to keep the county moving in the future.’