A crash that was partly blocking State Highway 1 on the Kapiti Coast has been cleared, but the NZTA is still warning revellers escaping the capital for Christmas to be patient as on the road.
The incident, which happened in the northbound lane just north of the Peka Peka Interchange, had put more pressure on the already clogged up route
An NZTA traffic update at 4pm said it was taking an hour to drive from Plimmerton to Otaki.
The 50km trip usually takes about 40 minutes, according to Google maps.
Other main highways in major cities have also been heavily congested.
The NZTA warned traffic was expected to remain heavy until 6.30pm.
The agency earlier urged holidaymakers to plan ahead and drive safely in an attempt to reduce traffic madness.
NZTA's nationwide map of holiday hotspots and times to avoid travelling showed traffic on Auckland's Southern Motorway, heading out of the city, is set to be at its heaviest between 11am and 6pm. Northbound traffic is also set to be bad from 11am to 4.30pm.
Those travelling north on State Highway 1 were warned to leave before midday, when the traffic between Puhoi and Wellsford was expected to become heavy.
The State Highway 2 Maramarua Interchange with State Highway 1 was also expected to be busy from 9.30am.
The annual Christmas rush kicked off yesterday afternoon with gridlock traffic heading out of Auckland and Wellington, made worse by a number of crashes.
A person was taken to Auckland Hospital with serious injuries after a car hit a tree on Whangaparoa Rd in Red Beach, Auckland. Crashes on the Northern and Southern Motorways, both heading towards Auckland CBD, also caused disruptions to traffic.
Traffic on the Central Motorway Junction was also heavy southbound due to minor incidents along with the onset of holiday traffic.
Commuters reported cars crawling to get onto the Auckland Harbour Bridge yesterday.
Traffic was also heavy around some of the key malls, including Sylvia Park in Mt Wellington, as people did their last-minute Christmas shopping.
Meanwhile, those heading out of the capital on the Kapiti Expressway faced delays of up to 30 minutes. Commuters should expect more delays in the area for most of today.
And, within hours of the official holiday period beginning, one person has already been killed on the road.
Abdul Raheem Fahad Syed, a 29-year-old taxi driver from Avondale - believed to be on his way to pick up passengers - was killed when a speeding black Mercedes allegedly ran a red light on Symonds St in central Auckland.