As tens of thousands of New Zealand holidaymakers funnel back into cities at the end of the de facto Anzac Day long weekend on Sunday, drivers may want to pick their travel times to avoid the worst traffic jams.
With a forecast of rain scattered into the mix in some places, there is the potential for some serious low-gear crawling.
Sunday afternoon is picked for the peak of the bumper-to-bumper driving in traditional traffic hotspots, but the New Zealand Transport Agency warns that in some areas the holiday headache could start as early as 10am or persist until 8pm.
The agency is also calling for calm, urging motorists to drive at a safe speed and to consider leaving early or late, or take an alternative route to avoid snarl-ups.
Because peak traffic flows are changed by crashes, weather and how drivers are behaving, the NZTA encourages motorists to check the latest information on its journey planner website before setting off.
State Highway 1 drivers aiming for Auckland from the north on Sunday are expected to face the heaviest traffic flows from midday to 6pm between Wellsford and Puhoi, while those coming from the south could be heading into a 1pm to 8pm lock-up on the Southern Motorway at Takanini.
At Maramarua on State Highway 2, the heaviest traffic westbound - carrying many travellers from the Coromandel Peninsula and Bay of Plenty - is expected to persist for 10 hours, from 10am to 8pm.
North of Hamilton near the Taupiri roundabouts that feed State Highway 1, the 11am-6pm period is expected to be the worst for northbound traffic.
At Karapiro, on State Highway 1 south of Cambridge, the heaviest flows are expected from midday to 5pm heading south, and 10am to 7pm northbound.
In the Wellington region, the usual Kapiti Coast jam on State Highway 1 is forecast from 11am to 5pm northbound, and 11am to 7pm heading south.
On the Rimutaka Hill road, State Highway 2, the traffic is anticipated to be at its worst from midday to 6pm.
"Congestion and delays are inevitable during holiday periods, so we also want to remind everyone to leave plenty of time for their journey, drive to the conditions and plan ahead before leaving home," NZTA safety and environment acting director Niclas Johansson said.
"Road safety is everyone's responsibility. Let's work together to make this a safe and happy holiday break."
He urged drivers to be guided by the conditions, which might mean a lower speed than the legal limit. Other advice was to always wear a seatbelt, avoid alcohol, don't drive when tired, focus on the task of driving, and put the phone away.
At Kawakawa in the Bay of Islands, people with stop-go signs be employed on Sunday to control traffic flow during the period of expected congestion at a pedestrian crossing over State Highway 1 and at its intersection with State Highway 11.
"We ask motorists to drive with care and expect hidden queues between Moerewa and Kawakawa at times," Johansson said.