Business leaders last night renewed calls for crucial improvements to the North-East road network after the Highways Agency was criticised for failing to tackle traffic jam misery.

The criticism came in a report by the National Audit Office (NAO) - the Government's spending watchdog - which said the agency had been slow to introduce measures to ease congestion.

It also said motorists were not properly served by roadside electronic message signs, while the agency was often unaware of sporting and entertainment events which could clog up major roads.

Andy Sugden, director of policy at the North-East Chamber of Commerce, said: "We are looking to the Highways Agency and the Government to invest in areas like the North-East where there is economic growth potential.

"We have a number of congestion pinch points - such as the Tees Crossing, the A1 Western Bypass at Gateshead and the Tyne Tunnel - which act as a barriers to business and for people getting to work.

"This report makes a number of suggestions that are worth considering and we would welcome any innovations to get traffic moving."

The NAO suggested allowing controlled use of the hard shoulder for traffic at peak times or in case of accidents; allowing for variable speed limits and introducing more dedicated lanes restricted to certain types of vehicle in order to speed their journey.

Malcolm Dodds, a North-East spokesman for the Road Haulage Association, said: "It would be interesting if the Highways Agency experimented more on particular routes, perhaps by introducing truck-only lanes and increasing the speed limit.

"But whether you criticise the agency or the Government, the biggest frustration for our members is the amount of revenue that is taken from them in return for a road network which is incapable of providing adequate access to deliver goods to the customer."

The recently-launched 20-year Northern Growth Strategy, supported by the regional development agency One NorthEast, said reducing congestion on strategic roads - such as the A1, A66, A69 and A19 - to below the national average must be a priority.

Commenting on the report, Edward Leigh MP, chairman of the public accounts select committee, said: "While many of our motorways and trunk roads are choked with traffic, the Highways Agency is timid and irresolute in taking advantage of congestion-reducing measures that don't involve road building.

"It must adopt a more pragmatic and visionary approach to new technologies, so that the best of them can start to be used to tackle traffic jam misery.