City-bound traffic is being diverted near the Auckland Harbour Bridge, after a crash near the Onewa Road off-ramp.
A van driver has critical injuries after colliding with a truck in the southbound lanes of State Highway 1 about 3.30pm.
All three southbound lanes are closed near the crash site.
Traffic is being diverted off the motorway at the Onewa Road off ramp to rejoin the highway via the Onewa Road on-ramp.
Commuters are being warned to expect delays.