The Puhoi to Warkworth motorway is now open to traffic.

Members of the public are taking to social media to share their excitement at the news of the opening, which has been highly anticipated by locals in particular.

On a local Warkworth community Facebook page, people started posting that the road had opened from about 5am.

Johnny Shore said he left Warkworth at 5am and was in the Auckland CBD by 5.35am.

“That’s no traffic,” he said.

Another person said the road opened late last night and that it took them 15 minutes to travel to Silverdale.

Car on fire on Auckland motorway

Meanwhile, emergency services are responding to a car fire on a southbound lane on Auckland’s Southwestern Motorway, just after Walmsley Rd.

The incident was reported by Waka Kotahi NZ Transport Agency at 6.20am.

Video footage from a traffic camera shows flames coming out of a vehicle with its driver’s side door wide open.

A number of people can be seen standing on the side of the motorway, as at least two vehicles have parked up with their hazard lights blinking.

Police are advising motorists to expect delays on the Southwestern motorway as a result.

“Police are assisting with the incident - near the Walmsley exit - which was reported around 6.15am.

“The fire is currently being contained by Fire and Emergency (NZ). However, some southbound lanes are blocked.”

No injuries have been reported, police said.

Pockets of thick fog

Auckland city covered in fog, looking across from Devonport. Photo / Hayden Woodward

The incident comes as motorists around the city are having to navigate heavy fog on parts of the motorway network and locals roads.

A woman driving into the city from New Lynn, West Auckland, said: “Visibility is terrible on Auckland’s western roads.”

Auckland Airport put fog restrictions in place overnight; with an alert being sent out just before 12.30am.

No flights have been affected, however.