An opening date for the long-awaited Transmission Gully is still unknown. 

So far, only a quarter of the safety and quality assurance tests required under the contract to build the highway have been signed off.

There are also 47 consent tasks that need to be completed -- of which only three have been done so far.

Waka Kotahi wants it open by Christmas, but can't promise it will be. 

The Wellington Regional Council is responsible for granting the environmental consents, such as those to do with planting, stormwater management and run-off from the construction site. 

Māni Dunlop talks to its chair, Daran Ponter.