Gini Welch, National road policing manager Acting Superintendent, called it a "devastating start" to the weekend.
"While it is too early to talk about the cause of these crashes, we will continue to relentlessly remind people we all have a part to play to keep our roads safe," she said.
"Most people behave safely on the roads most of the time, but it only takes one risky decision or moment of inattention to result in tragedy. Ultimately, the actions of every driver and rider makes a difference."
Heavy rain and strong winds lashing the South Island are expected to hamper road conditions from this evening, with congestion expected as those on a weekend getaway return home tomorrow.
Waka Kotahi/NZTA urged motorists to plan ahead and be patient when they hit the inevitable traffic jams.
"The roads have been very busy as people take advantage of the first long weekend since June, and we know that traffic heading back in to the main centres will be very heavy tomorrow," said Greg Lazarro, Waka Kotahi general manager safety, health and environment.
"Congestion and some delays will be unavoidable at peak times, so we're asking everyone to allow plenty of time for a safe trip home."
But tragedy has struck five families as many enjoy a day off work or school.
The weekend period started at 4pm on Friday and runs until 6am on Tuesday.
Just an hour after the weekend period started, a motorcyclist was killed in rush-hour traffic.
The crash happened on Main Rd North (State Highway 2), in Timberlea, Upper Hutt, on Friday.
A second person was killed in the early hours of Saturday morning near Gisborne.
Emergency services were called to the crash on Whatatutu Rd, Te Karaka, just before 2am.
Seven hours later, emergency services were called to a two-car crash along State Highway 8, near Tekapo.
Che Tekapa Hogg, 42, was killed and three others injured.
The trio was airlifted to Christchurch Hospital with serious injuries.
A pedestrian died on Saturday afternoon after being struck by a heavy vehicle near Whanganui.
The incident occurred around 2pm on State Highway 3 at Westmere.
And the fifth person died after a car rolled on State Highway 35 in Tikitiki, on the East Coast north of Gisborne, shortly after 2pm on Sunday.
Police continue inquiries into all five crashes.
Today Welch again urged motorists to slow down and drive safely.
"Too many people have already lost their lives or been seriously injured on the roads this weekend," she said.
"Please watch your speed and following distances, pay attention to the conditions, and stop and take a break if you're feeling fatigued."
