Holidaymakers north of Auckland are stuck in gridlock near the Johnstone tunnels.
Northbound traffic is at a standstill on State Highway 1 on the 35km stretch between Puhoi and Wellsford.
A Herald photographer at the Hillcrest overpass said traffic was "chockablock" with the queue of cars tailing back as far as the eye could see.
He said most of the cars appeared to be full of people looking to make the most of the summer break with boats and jet skis in tow.
The NZ Transport Agency (NZTA) is advising motorists to avoid the tunnels and take State Highway 16 instead.
Google Maps' route planner is estimating the usual one hour journey from central Auckland to Wellsford is now taking more than two hours.
For the holiday season, NTZA produced a handy travel planner informing motorists when to avoid the motorways for maximum happiness.
Based on previous years' holiday traffic, NZTA is predicted SH1 between Puhoi and Wellsford would be at its heaviest between about 10am and 6pm.
Southbound traffic from Auckland, meanwhile, was expected to be more free-flowing and there currently aren't any delays.
Traffic was expected to only be at its heaviest between 9.45am and 10.30am today, NZTA's data shows.
Meanwhile SH1 north of Whangarei is also expected to have its worst day for traffic of the holiday period as people drive north to holiday spots in the Bay of Islands.
From 10am to 5.30pm today traffic is expected to be at its heaviest for the holiday period northbound from Northland's biggest city.
To find the most up-to-date information on your travel route, check the NZTA's Journey Planner
NZTA's top tips for safe holiday driving
• Check your car is in good "health" before you head off: Check your tyre pressure and tread, windscreen wipers, indicators and lights.
• Take extra care when travelling in holiday periods because of increased traffic volumes, congestion, tiredness and people driving in unfamiliar environments.
• Drive to the conditions: whether it's the weather, the road you're on, the time of day or amount of traffic.
• Avoid fatigue: Take regular breaks to stay alert.
• Keep a safe following distance from vehicles in front so you can stop safely.
• Be patient: overtaking is unlikely to make a significant difference to your journey time due to the amount of traffic expected over the weekend.