Traffic is starting to move freely on a major Auckland motorway after a serious one-car crash closed all southbound lanes.

The driver was taken to Auckland hospital in a serious condition after the crash on the northern motorway.

Significant southbound delays built up 1.5km north of Lonely Track Rd, according to NZTA.

A police spokeswoman said about 12.50pm one vehicle crashed after possibly having hit the centre barrier.

Advertisement

The crash which occurred just south of the McClymonts Rd initially led to the closure of all southbound lanes.

They have since re-opened.

At 2.40pm NZTA advised that the traffic queues were roughly 500m.