Delays are expected after both southbound lanes of State Highway 1 were closed on the Southern Motorway when a campervan crashed onto its side today.

SH1 SOUTHERN MWY - CRASH - 12:05PM

A crash is blocking the right lane SOUTHBOUND, near the Nikau Rd off-ramp, on the Bombay Hill. Merge left to pass with care & expect delays. ^TP pic.twitter.com/LLR87SRkpT — NZTA Akld & Nthlnd (@NZTAAkl) April 12, 2019

The accident happened at about 12pm near the Nikau Rd off-ramp on the Bombay Hills.

While one lane was initially blocked, both lanes were closed to recover the vehicle. They have now been reopened.

NZTA has asked motorists to expect delays and be patient.