Traffic woes: Gridlock again at notorious Johnstone's Hill Tunnel near Pūhoi

A second day of traffic congestion north of Auckland is plaguing the exodus of holidaymakers leaving the city for summer.

Motorists are down to a crawl at the Johnstone's Hill Tunnel near Pūhoi on State Highway 1 for the second consecutive day, according to reports on social media.

Traffic backed up at the Johnstone's Hill Tunnel south of Pūhoi for the second consecutive day as holidaymakers head north for the summer. Photo / Elizabeth Balogh/Facebook

Yesterday the NZ Transport Agency recommended motorists avoid the backlog and re-route to State Highway 16, which rejoins the main highway at Wellsford.

The usually one-hour trip from Auckland central to Wellsford was yesterday reportedly taking at least two hours.

On the Warkworth and Districts Traffic Updates Facebook page, Julie Scott posted a photo of the congestion earlier today saying: "It's started early this morning".

While the southbound lanes were clear, traffic was backed up as far as the eye could see in the photograph.

The backlog on State Highway 1 north of Auckland began earlier today after being clogged yesterday too. Photo / Julie Scott/Facebook

For the holiday season, NTZA produced a travel planner informing motorists when to avoid the motorways for best travel.

Based on previous years' holiday traffic, NZTA predicted SH1 between Pūhoi and Wellsford would be at its heaviest between about 10am and 6pm.

Last night, a crash at Te Hana on SH1, north of Wellsford, also caused delays.

By 8pm, the crash had been cleared and congestion eased, NZTA tweeted.

Police have warned motorists to take it easy, drive to conditions and take regular breaks.

The road toll stands at one after a pedestrian was killed in Blenheim Friday night.