A BLACKSPOT road condemned as one of the most congested rush-hour routes in the country is to be upgraded at last.

Work will finally start to turn the A556 link road - between the M56 and M6 motorways - into a dual carriageway between Knutsford and Bowdon.

There were 200 accidents there between 1998 and 2005, including five deaths and 39 serious injuries.

The A556 carries about 50,000 vehicles a day - including nearly 10,000 lorries - and a government survey two years ago said it was the most congested rush-hour route in the country.

It recorded average delays of between 22 and 24 minutes for every 10 miles travelled in the morning and evening peak periods on a four-mile stretch.

The improvements, costing between £142m and £207m, bypass Mere and Bucklow Hill, but work will not be completed until 2015 at the earliest, subject to legal procedures and funding.

Transport minister Andrew Adonis said: "I am delighted to announce the preferred route for this vital improvement to the A556, which connects two main motorways linking Manchester and the West Midlands.

"Upgrading the key route to dual carriageway standard will bring improved journey times and increased road safety to one of the most heavily congested roads in Britain.

"It is good news for the residents in of Mere and Bucklow Hill as the bypass will take large volumes of traffic away from these communities. The scheme will also help the economic regeneration of south Manchester."

The `preferred route', developed after public consultation between March and July 2007, includes a new two-level junction at the A50 Warrington Road to provide access to the bypass.

Land near the route will be protected from development and plans can be obtained from the Highways Agency.

Detailed work will now be carried out to determine which land will be required.

The public will still be entitled to make comments and a public inquiry could be held into any objections.