Work to resurface the A12 road between Copdock and East Bergholt starts next Monday night – which is when the average speed cameras in the area will be switched on.

The six-mile stretch of road already has a temporary speed limit – and this will be enforced over the next eight to 12 weeks while the work is going on.

The resurfacing, like the work to improve crash barriers that has already started, will be carried out overnight. However it will leave uneven surfaces which is one of the reasons for the temporary speed limit.

A spokeswoman for the Highways Agency said the limit needed to be in place because temporary crash barriers had already been installed at some locations on the road which required a lower limit for drivers on the carriageway.

She said it was not possible to have shorter stretches of 40mph speed limit which would have to move as the work continues.

As well as resurfacing the road and replacing crash barriers, the engineers will also install new road signs and improve road drainage.

Highways Agency project manager, Anna Graham said: “We’re pleased the preparatory work has been completed and now the second phase can begin.

“This is a multi-million pound scheme which is taking place to prolong the life of the carriageway. The work has been designed to improve the surface of the road and safety for road users, while minimising the need for future maintenance works in these locations.

“The main work will be carried out at night using contraflow so the road remains open. During the day the road will be open with two lanes operating in both directions.

“We ask that drivers should be aware of the temporary road surface, take care travelling through the roadworks and adhere to the 40mph speed limit.”

The work is dependent on suitable weather conditions, and may take longer if conditions become particularly harsh.