A new report by the Auditor General for Wales says that the Welsh Government’s A465 Gilwern to Brynmawr dualling scheme is now due to run into 2021, having previously been set to finish in September 2018.

It adds that the project – which involves upgrading 8km of road in a steep sided valley – will cost the public purse around £100M more than its initial £223M budget. Geotechnical engineering challenges facing the scheme and contractual disputes with main contractor Costain are considered to be the main reasons for the set back.

“This is not the first time that the Welsh Government has faced difficulties with significant cost increases and delays on road projects and it is vital that lessons are learnt for future infrastructure schemes,” said Auditor General for Wales Adrian Crompton.

“Despite some wider benefits being delivered and expectations about the eventual impact of the road improvement, those living and working locally are paying a higher than expected price for the ongoing delays and disruption during construction.”

The Gilwern to Brynmawr project forms section two of a larger 40km A465 Heads of the Valleys upgrade programme from Hirwaun to Abergavenny.

A written statement by the Welsh Minister for Economy & Transport Ken Skates said construction is more than 85% complete. But difficulties have been experienced in relation to an unstable slope and Costain advised that work to build a retaining wall is taking longer than originally envisaged.

“Consequently, they have extended the programme end date to April 2021,” he wrote. “I am obviously very disappointed by this further delay and have asked the project team to continue to explore what can be done to bring forward these programmed dates.”

“I remain confident that this ambitious and complex scheme will bring significant benefits to the region,” he added. “Once complete, the project will improve access to key public services and jobs and complete a dual carriageway between the English midlands and the Heads of the Valleys, including the Ebbw Vale Enterprise Zone.”

Confederation of British Industry Wales director Ian Price commented: “With connectivity in Wales such a pressing issue, it’s disappointing to hear about a further delay to work on the A465.

“Levelling up our economy and ensuring that the proceeds of growth are felt across all parts of Wales depends on improving digital and transport infrastructure.”

Costain was approached for comment.

(Photograph: Costain)