Road congestion is taking its toll on the supply chain the Freight Transport Association has warned and costs the British economy £20bn a year, according to the Confederation of British Industry.

FTA chief executive Richard Turner commented: "We have a world class transport and logistics industry but it is suffering major problems out on the public road network. Only government can solve this reliability problem - no matter how well we engineer our supply chains they will fail on a poor network.

"The economy, the industry and all road users are entitled to expect a motorway network of a 21st century standard, fit for the purpose of moving freight and people."

Earlier this week transport minister Alistair Darling revealed that government efforts to cut congestion by 6% over the next seven years would not be met. Last week he announced a £5.5bn package of nationwide transport improvements which included a £3bn road building programme.

Meanwhile, the FTA has drawn up a list of the top ten motorway junction snarl-up points - four of them on the M25 - at the Dartford River Crossing; Heathrow M4; Uxbridge M40; Virginia Water M3.

The others are at the M4/M5 junction, Almondsbury, Bristol; M5/M6 junction, Birmingham; A14/M11 junction, Cambridge; M40/A46 junction, Warwick; M56/M60 junction, Northenden, Manchester; and M62/M60/M602 junction Worlsey, Manchester.