The Central Western Daily was informed work had stalled two weeks ago and NSW Roads and Maritime Services (RMS) confirmed an irregularity was found in the density testing of earth work layers.

“Work on the upgrade of the Mitchell Highway at Guanna Hill is continuing although the work schedule has been delayed after a non-conformance was found ... during a routine audit,” a spokeswoman said.

“Prior to this, the project was on track for an early completion.”

Verification testing and analysis is ongoing to determine if further action is required, however the spokeswoman said all earthwork material supplied to the site was compliant.

A spokesman for the National Association of Testing Authorities said if the density testing was incorrect, there was a risk of premature failure, including cracking.

The state government committed $56 million to the 7.2-kilometre stretch of road just south of Molong, with work starting in July last year.

It is 85 per cent complete and expected to finish early next year with final earthworks, revegetation and completion of stormwater drainage under way.

Asked whether she was concerned about delivering a sub-standard road, NSW Roads Minister Melinda Pavey said strict guidelines ensured work was of the highest quality “for all road construction contracts”.

“RMS is undertaking continuous testing to ensure all material complies with all necessary standards to ensure that a properly constructed road is delivered,” she said. 

With two recent fatalities between on the highway between Orange and Bathurst, Ms Pavey pointed out $2.1 million was spent earlier this year to widen the road shoulders along a 1.8-kilometre section at Vittoria to reduce crashes occurring from vehicles leaving the road.