Brace yourself: Friday is expected to be one of the busiest days of the year for drivers fleeing Auckland and Wellington.
It's also expected to be one of the worst days of the year for drink driving, as people down a few beers or wines with colleagues on their last day of work.
But police hope free public transport, and warnings of extensive breath testing points, will stop people getting tipsy or drunk and then getting behind the wheel.
Public transport will be free from 4pm tomorrow under Auckland Transport's Home Free promotion, with customers with HOP cards who tag on after 4pm receiving no charge on their account.
Tāmaki Makaurau road policing manager Inspector Scott Webb urged people to leave their cars at home, saying the initiative would let people enjoy an after-work drink and still get home safely.
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Auckland police will also be out in force breath testing people to make sure they're not tipsy or drunk when they get behind the wheel.
AT staff and police have been conducting checkpoints across the city over the past two weekends, with a "disappointingly" high number of people caught driving under the influence, police said.
In Counties Manukau, more than 15,700 vehicles have been stopped and tested, with 168 people being processed for alcohol-related driving offences.
A large number of them were several times over the legal limit, with 97 people heading to court on alcohol-related charges as a result.
Webb said the figures were very concerning, and there was absolutely no excuse for motorists to be drinking to excess and then driving.
For those lucky enough to be leaving Auckland after finishing work on Thursday, the NZ Transport Agency has crunched the numbers to work out exactly when the traffic will be heaviest.
The interactive holiday journeys map shows predicted traffic flow across the Christmas / New Year period.
For Aucklanders heading south, the worst bottleneck will be around Takanini and Papakura, while northbound the heaviest traffic will be between Puhoi and Wellsford.
Based on previous years, traffic at both pinchpoints is expected to start building at 11am tomorrow, and by 12pm it's expected to be at a crawl, only calming down after 8pm.
If you want to hit the road running, leave early tomorrow morning or leave the driving till after dark.
But don't wait till Saturday. Traffic is expected to build on the Southern Motorway from 8am and won't calm down till after 6pm, while northbound motorists should see the traffic ease around 5pm.
If previous years are anything to go by, Sunday's traffic is expected to be much calmer heading south with only a brief heavy period mid-morning. But northbound traffic will remain heavy from 9am to 5pm Sunday.
While the traffic predictions are based on past data, factors like weather and driver behaviour could see patterns change.
It's also hoped that the recent widening of State Highway 1 to three lanes each way between each Takanini and Papakura will ease congestion.
THE NZTA'S SAFE DRIVING TIPS
• Check your car is in good "health" before you head off. Check your tyre pressure and tread, windscreen wipers, indicators and lights.
• Take extra care when travelling in holiday periods because of increased traffic volumes, congestion, tiredness and people driving in unfamiliar environments.
• Drive to the conditions - whether it's the weather, the road you're on, the time of day or amount of traffic.
• Avoid fatigue. Take regular breaks to stay alert.
• Keep a safe following distance from vehicles in front so you can stop safely.
• Be patient – overtaking is unlikely to make a significant difference to your journey time due to the amount of traffic expected over the weekend.
• Allow plenty of time. Remember you are on holiday, so there's no need to rush.
• Check the NZTA's journey planner for crashes or road closures en route.