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.
One driver commented the traffic had been at a crawl for about two hours just north of Paraparaumu, with cars travelling at a speed of around 10km/h.
The same route had been heavily congested on Wednesday, with the agency reporting traffic did not ease until about 7pm.
Unlike on Wednesday, Paekākāriki Hill would be open on Christmas eve.
Earlier in the day the transport agency had also asked travellers to plan ahead for roadworks on SH1 at Mackays Crossing.
With the Wellington region also hit with wet weather on Thursday, MetService meteorologist Lewis Ferries recommended travellers allow plenty of time to drive to the conditions.