A serious crash on Auckland's northern motorway has blocked all lanes near the Onewa Road off-ramp.
SH1 NORTHERN MWY, NORTHBOUND - CRASH - 1:15PM— NZTA Akld & Nthlnd (@NZTAAkl) August 21, 2018
A serious crash is blocking ALL LANES north after Onewa Rd. All traffic being diverted off the motorway at Onewa Rd. Avoid this route or expect diversions and delays. ^TP pic.twitter.com/Oblo5fwFzF
Police said one person has been seriously injured after a vehicle rolled north of the off-ramp.
All northbound lanes have been closed by the crash, with traffic diverted off the motorway at Onewa Road.
Police have warned this will cause significant traffic disruption and motorists are urged to avoid the area if possible.
It is not known how long the motorway will be closed.
NZTA said motorists should avoid heading for the Auckland Harbour Bridge and to use alternative routes north via the Western Ring Route on SH16 and SH18.