A serious crash north of Whangarei has closed State Highway 1 as holidaymakers head to the Bay of Islands and other holidays spots for Auckland Anniversary weekend.
Police said SH1 is closed at Whakapara, 24km north of Whangarei after a two-car crash near Puhipuhi Rd about 5.50pm.
Two people have sustained critical injuries.
The road is expected to be closed for some time and motorists are advised to avoid the area, if possible.
The crash comes as traffic is crawling on Auckland motorways as holidaymakers flee the city for the weekend.
On the Southwestern Motorway, a crash was blocking the centre southbound lane prior to the Walmsley Rd off-ramp.
The New Zealand Transport Agency told motorists at 3.35pm to expect delays and pass the scene with care. The lanes have since been cleared.
An earlier crash on the Northern Motorway southbound just after Shelly Beach Rd was also causing delays.
And several people have reported traffic is almost stationary just south of Warkworth.
Traffic is bumper to bumper back to the BP station just before the Silverdale turn-off, Diana Kramer reported on the Warkworth and Districts Traffic Updates Facebook page. Another frustrated driver said it took 42 minutes to travel from Onewa Rd to the Mahurangi West turn-off, just north of Puhoi.
Motorists who want to avoid the snarl-ups are being directed to a new tool that has been set up to help those heading away for the long weekend.
Motorists can work out exactly what times are usually the quietest and, therefore, best time to hit the road or - more importantly - what times are the busiest and should be avoided at all costs.
The Holiday Journeys map has been released by the NZ Transport Agency.
"Plan your journeys in advance with the help of our Holiday Journeys map. It shows predicted traffic flows based on previous years' travel patterns."
Anyone travelling from Auckland to Puhoi and Wellsford today would be best to avoid the roads between 2pm and 7pm, when congestion is expected to be the heaviest.
But even getting on the road between 11am and 8pm will set you back, as the map shows the area as being "busy" during that period.
By 11.30am, motorists were reporting queues starting to build at Warkworth.
People preparing to head northbound tomorrow will have to be up early to avoid the traffic jams predicted from 8am to 4.30pm. Peak traffic is expected to be between 11am and 2pm.
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Driving back home on Monday might be an unwanted mission if you choose to travel back any time from 9.30am.
The heaviest traffic is expected to last several hours - from 10.30am to 4pm.
The interactive map also includes travel and traffic time predictions for those heading further out to Northland and to the Bay of Plenty and Waikato regions.
Back in Auckland, anyone heading to tonight's Black Caps versus India cricket
match, at Eden Park, is being encouraged to consider using public transport to get to and from the game.
WEATHER CONDITIONS FORECAST TO BE HOT, HOT, HOT
On the weather front, conditions are forecast to be mainly sunny and very hot over the weekend and weather authorities are reminding people of the basic rules when out in the sun: "Slip, slop, slap and wrap."
Temperature highs in the mid to late 20s and early 30s are forecast for parts of the North Island over the weekend.
Niwa Weather says the UV Index will be "high to extreme" across most of New Zealand over the next few days.
Today's morning clouds in parts of the North Island, including in Auckland in particular, will make way for mostly settled weather, according to WeatherWatch.
Tomorrow brings mostly sunny conditions again for the North Island - but there will be morning cloud for western areas.
In the South Island, there will be heavy rain in the morning for South Westland areas; but those will turn into the odd shower before clearing later in the evening.
People in Otago can also expect a mostly cloudy day tomorrow, save for the odd shower.
MetService is forecasting morning low cloud or fog in parts of the North Island on Sunday but it is otherwise a mainly fine day.
On Monday, people who decide to have a stay-cation in Auckland can expect a partly cloudy day with southwest breezes and a high of 27C.