Traffic crawling on Auckland's Southern Motorway

A crash is blocking the third southbound land on the Northern Motorway just before the Auckland Harbour Bridge.

NZTA said motorists should expect delays and take extra care after the crash about 6.50pm.

Meanwhile, Auckland's Southern Motorway remains gridlocked southbound after two minor crashes earlier this evening.

Commuters who live in South Auckland and work in the city were likely to have spent well over an hour in traffic this evening.

NZTA said just before 5pm that Auckland's Southern Motorway was so heavily congested southbound that it was taking 85 minutes to travel from the CBD to Manukau.

Two minor crashes about 5.40pm added to the chaos.

The first - a nose-to-tail - near the Otara off-ramp was not blocking. But another near the Princes St off ramp, which police said involved four cars, was partly blocking one of the lanes.

One of the vehicles involved in the four-car crash was undriveable, a police spokeswoman said.

The crash has since been cleared, but the motorway is still heavily congested in the area more than an hour later.

No injuries were reported from either Southern Motorway crash.