Two lanes of one of the busiest routes in and out of Wellington will close this afternoon because of rockfalls.

The two southbound lanes and a footpath on State Highway 1 south of Newlands through the Ngauranga Gorge will close at 12.30 today so crews can clear up a small amount of material and install concrete barrier protection, the NZ Transport Agency said.

The work is only expected to take an hour or two and will only affect southbound traffic, said regional transport systems manager Mark Owen.

"This is one of the busiest routes in and out of Wellington and we understand the importance of completing this work as quickly as possible," he said.


"One lane will still be available to southbound traffic, but road users may face delays.

"We are putting in barriers because there has been a lot of rain lately and we need to remove the debris and [assess] the area."

This means the footpath will remain closed until the work is completed.

An update will be posted on the NZTA website and social media pages as soon as the additional lanes and footpath are reopened.