A serious crash on Remutaka Hill has closed State Highway 2 on the Upper Hutt side of the Hill near Kaitoke.
At least one person is critically injured.
NZTA advise that the Serious Crash Unit is currently on site and have asked road users to avoid the area and delay travel.
The road is closed in both directions and there are likely to be lengthy delays.
NZTA contractors are currently on site working to open Remutaka Hill as soon as possible.