During the closure, due to start on 17 July, the carriageway will be rebuilt and drainage and resurfacing work will be carried out.

The works clash with improvements on the M4 between Bristol and Bath to install electronic traffic signs.

The combination of both sets of works on the corridor between the two cities may lead to queues for commuters.

During the work on the A4, access to the village of Saltford will be maintained with local businesses and residents issued with passes allowing them to be fast-tracked past the gates.

Traffic between Bristol and Bath will be diverted around the area.

Diversions signed

"The existing carriageway has reached the end of its life and the substructure of the road now needs to be rebuilt," said Dave Sledge, Highways Agency project manager.

"We will also be laying a new low noise surface, replacing drainage and damaged kerbs together with the resurfacing of the adjacent footpath.

"Water and gas companies will also use the opportunity to re-lay extensive lengths of their mains, reducing future disruption."

During the period of the works traffic will be diverted.

Westbound traffic will be taken off the A4 at the Globe Roundabout onto the A39, before rejoining the A37 north towards Bristol.

Eastbound traffic will be diverted off at the Keynsham Roundabout via the A4174 (Avon Ring Road), east onto the A420 and south onto the A46 to rejoin the A4 east of Bath.