One of the country's biggest motorway projects has been beset by critical problems with its technology for cameras and speed signs.
The risks to Transmission Gully north of Wellington are briefly mentioned in New Zealand Transport Agency (NZTA) documents released to RNZ.
These record a warning early this year to a governance group, saying "concerns with the technology integration ... has been on red for some time".
"Red" denotes the most critical of four categories of project risk.
The technology covers cameras, sensors and speed signs, that provide crucial information to transport operations controllers.
The agency has refused RNZ's Official Information request to spell out what was going wrong, on the grounds it was commercially sensitive.
It had earlier conceded the Transmission Gully project - worth almost a billion dollars - is likely to be delayed past next May due to what it called "critical construction" hold-ups.
The new documents show the agency decided it was "prudent" to let the consortium, that is both building the road and running the technology afterwards, work through a four-point plan to get on top of the red-zoned problems.
But instead of the agency setting the standards, the consortium was, though the tab for that fell on the taxpayer.
"This was the wrong way around and vendors should be meeting NZTA needs," the project briefing to the agency's IT governance group said.