Congestion is not expected to ease until 8pm on Christmas eve for Wellington holiday makers heading north from the capital.
At 11am Waka Kotahi NZTA Wellington advised there were still major northbound delays on State Highway 1 (SH1) between Waikanae Beach and Ōtaki, with queues growing at Te Horo and Peka Peka.
They later updated delays at Peka Peka had "eased slightly" but remained between Te Horo and Ōtaki.
State Highway 2 was reportedly free-flowing.