It's holiday traffic nightmare on the roads with holidaymakers experiencing bumper-to-bumper traffic across many parts of the country.

Waka Kotahi NZ Transport Agency was urging drivers to allow extra time for their journeys due to holiday traffic creating busy roads, and crashes causing closures.

State Highway 1 from Puhoi to Warkworth is blocked due to a crash near Cowan Bay Rd.

Motorists are urged to follow directions by emergency services and to expect significant delays in both directions.

In Waikato, State Highway 25 is closed at the Hikuai River Bridge due to a crash. The agency said contractors and tow trucks are now on site.

Congestion warnings have been put in place also on SH25 for both directions in Tairua and southbound on SH1 between Cambridge and Tirau. The agency is urging motorists to allow extra time for their journeys and to expect delays.

It is also a slow crawl for motorists heading north due to holiday traffic, with massive delays on SH1 northbound between Puhoi and Wellsford.

The holiday toll reached 11 when a motorcyclist died after coming off the road in Northland just after midnight.

The male rider died at the scene on State Highway 12 in Kaihu around 12.20am.

A motorcycle passenger received moderate injuries and was taken to Whangārei Hospital for treatment.

The Serious Crash Unit is investigating.

The Christmas-New Year holiday road toll period finishes at 6am on Wednesday.