THERE are less than three weeks to go before a £22million scheme to rebuild the Bournemouth Spur Road gets underway.

And motorists are being warned that the lane closures will have an impact on traffic across Bournemouth and surrounding areas.

The council is not allowed to suggest alternative routes, because official diversions have to be via roads of the same category as the A338. But this map produced by Dorset County Council warns of the alternative routes that could become congested.

These include:

* The A31 from Ashley Heath and through Ferndown and Longham.

* The A3060 through Kinson and Castle Lane.

* The B3073 through Hurn.

* The B3347 through Avon Castle, Sopley and Burton.

* The A35 from the New Forest to Christchurch.

Dorset Echo:

Cllr Peter Finney, cabinet member for environment, said: "Bournemouth and Christchurch are open for business as usual but drivers will have to alter their habits and think more carefully about how they are going to get to their destination on time - alternative travel methods, car sharing and travelling outside peak hours will all help."

The roadworks will start on September 6, when there will be day time and night time closures on the northbound and southbound carriageways for two weeks. During this time work will focus on removing any remaining vegetation. installing traffic management, speed cameras and CCTV and resurfacing works around Blackwater.

Work on constructing the carriageway will begin in earnest from September 21. Until Christmas, work will focus on the stretch of southbound carriageway between the Blackwater Junction and the QinetiQ access. All motorists will have to use the northbound carriageway, where a 40mph contraflow will be put in place.

In the New Year, work will switch to the northern end of the scheme, with the reconstruction of a one-mile stretch between Ashley Heath roundabout and the QinetiQ entrance. Work will start on the southbound side, with traffic remaining in the northbound contraflow and then the works area and contraflow will swap sides.

From March until the end of May, the northbound carriageway will be reconstructed and all traffic will use the newly built southbound side.