MOTORISTS are being given advance warning that there will be night time closures on the Heads of the Valleys road next month.

The week long night time closure on the A465 between Gilwern and Brynmawr will come into force on May 11 and not from tomorrow as previously planned.

Work to dual the 8.1km section began in December and is expected to take 180 weeks to complete.

The construction firm Costain Limited, which was appointed to complete the scheme, said the closures are necessary for workforce and public safety.

An update on the project’s website said: "As the construction programme advances from initial site clearance and access provision to a new phase that will include the demolition of some properties and early construction activities, these closures are necessary for workforce and public safety during the installation of lane barriers and some relining of the remaining two running lanes.

"This can only be safely undertaken within a full closure and the duration advised will, wherever possible, be reduced."

The design for the scheme includes a 50mph speed limit, improved junctions, extra laybys and a split-level carriageway.

A 40mph speed limit is currently in force on the A465 along with traffic control between the Glanbaiden rounabout at Gilwern and Brynmawr.

A lane closure will effectively reduce the traffic flows to a single lane in each direction and facilitate general site access and the start of early site clearance

A Welsh Government spokesman said every effort will be made to minimise the disruption to traffic particularly during peak movements at each end of the day and asks the travelling public to be patient and to conform to the new reduced speed limit.

Details of the night closures, diversions and arrangements for traffic crossover movements at the Saleyard and Gilwern junctions under traffic light control during the closures will be posted on www.a465gilwern2brynmawr.co.uk/ from May 4.