There was a massive disruption on Auckland’s Southern Motorway during this morning’s commute due to an “incident”, police say.

NZ Transport Agency Waka Kotahi said all northbound lanes were temporarily blocked between Cavendish Dr and East Tamaki Rd.

“Consider using SH20 and expect delays,” the agency wrote.

The lanes reopened at 8.30am.

A police spokesperson said emergency services were on the scene of the “police incident” and motorists should expect delays.

89 flights cancelled, delayed

Meanwhile, 44 regional flights were cancelled and another 45 flights delayed after thick fog descended on Auckland overnight.

Auckland Airport removed fog restrictions at 12.18pm.

A spokesperson said approximately 44 domestic flights were delayed and 45 domestic flights were cancelled due to the fog.

Heavy fog also shrouded much of the city’s motorway network, making driving difficult, and delayed ferry services.

MetService forecaster Lewis Ferris said it was a mixing pot of bad ingredients that was causing the fog to hang around.

He said MetService was expecting visibility to increase from now until midday as the sun begins to heat up the ground.

Ferris said the sun’s low angle due to the winter solstice, high clouds blocking the sun, and the lack of wind, made for the perfect foggy conditions.

Flight restrictions were put in place shortly before 3am, Auckland Airport said in a statement.

The airport said that as of 9.30am, 41 domestic regional flights had been cancelled and 30 domestic regional flights have been delayed, due to the fog.

Three flights from Christchurch, two flights from Wellington, and one flight to Wellington have been delayed.

However, flights to Christchurch and Queenstown had been cancelled for reasons unrelated to the fog, an airport spokesperson said.

Passengers are advised to check the airport’s website or app for the latest information on their flight.

Fog covering the Viaduct in central Auckland overnight. Photo / Hayden Woodward

Auckland Transport said the fog had caused delays to some ferry services to and from downtown Auckland, including Bayswater, Hobsonville and Beach Haven, Gulf Harbour, Pine Harbour, and Birkenhead. Several sailings were cancelled or 30 minutes or more late.

Video taken from the Hobsonville ferry terminal at about 7.20am shows pea-soup fog covering the water, with low visibility.