Tragically nine people have been killed in eight crashes since August 19. This figure included Northland's Tristan Kearney, 43, who died after his vehicle collided with a tree in Peria, near Kaitaia, on August 23.
Police commissioner Andrew Coster said emergency services continue to be called to serious and fatal crashes throughout New Zealand despite the travel restrictions in place.
"Even with less traffic on the road, it is vital that everyone continues to focus on the basics - drive within the speed limit and at a safe speed for the conditions, ensure everyone in the vehicle is properly restrained, don't drive while impaired, and put your phone away."
Less than 10 days into alert level 4, Northland District Commander Superintendent Tony Hill pointed out that "for some reason" the driving capabilities of the region's road user's had "deteriorated" during lockdown.
Roadsafe Northland and Northland Road Safety Trust chairman John Williamson wrote in a column, published in the Advocate, international research revealed a number of explanations behind altered driver behaviour during lockdown.
"These include increased stress, more idle time, greater opportunity for reckless driving with a perceived reduction in enforcement and increased consumption of drugs and alcohol.'
"It's the change in drinking behaviour that is of most concern," he wrote.
Williamson referred to last year's Global Drug Survey, which ran a study with more than 40,000 respondents worldwide including 300 Kiwis. It found of the Kiwi respondents, 20.7 per cent reported drinking a lot more during lockdown, with a further 30.2 per cent drinking a bit more than usual.
"This was the biggest increase of all the countries surveyed, the global average of people drinking a lot more, being 13.5 per cent. We also recorded very high numbers of people increasing instances of binge drinking, well over the global average."
Driving concerns aside, police were overall pleased with the level of compliance with alert level 4 restrictions among Northlanders - minus protesters and a few unruly individuals.
Since lockdown started on August 17 and 5pm on September 1, Northland police have arrested and charged 16 people with Covid breaches, provided 24 warnings, and referred two people to Youth Aid. Officers have also issued 318 infringement notices.