NZTA warned road users to plan ahead and choose alternate routes with roads expected to be busy until 8pm this evening.
Traffic was heavy heading into Auckland from the North, with congestion from Wellsford to Puhoi.
The alternative route of SH16 via Helensville was also congested, especially around Old North Rd.
An image sent in by a motorist this afternoon shows a long queue of vehicles backed up on Old North Rd waiting to get onto SH16.
From the south traffic was building from Bombay to Papakura.
Waka Kotahi says holidaymakers travelling into the capital can also expect a lengthy journey along the Kapiti Coast, with the heaviest traffic expected between 11am and 5pm.
The highway from Otaki was expected to be busy from 10am.
Meanwhile, a crash has closed a section of SH35 in the Gisborne region with motorists in the area urged to take extra care.
The road in Te Araroa is closed near the intersection with Te Arawapia Rd and a detour is in place, NZTA advised via Twitter.