"This is particularly tragic, especially for their whanau ... people presumably of good health, they had a future yesterday, but now they are gone."
Greally said the crashes were often a result of poor decision making, and failure to drive to the conditions.
"We've got to adjust the way we behave on our roads, it's not too difficult," he said.
He said the high road toll would have left families, friends and loved ones dealing with grief and loss.
Greally said nobody woke up in the morning wanting to get on the road and kill someone.
"Unfortunately, in the business that the police are in, we come across people who don't see things the way we do," he added.
Two cars collided on State Highway 6 near Clover Rd at about 5.40am on Sunday morning.
Police have confirmed they tried to stop a vehicle on nearby Gladstone Rd.
"The car failed to stop and fled towards State Highway 6, overtaking a truck and moving onto the wrong side of the road where it crashed into another vehicle that was travelling north," Superintendent Mike Johnson said.
"Tragically three people have died as a result, two of the deceased were from the fleeing vehicle and the third person was an innocent member of the public.
"An outcome like this is the last thing police want to see."
Johnson said next of kin were still being notified of the crash.
"We now have three families who have lost members and our thoughts are with them during this difficult time."
Johnson said this kind of incident was "extremely testing" for police, who aimed to protect their community.
"They are fast-moving, unpredictable and high-pressure situations that require quick judgements."
The crash will be investigated and the Independent Police Conduct Authority has been notified.
"Our staff go out every day and I ask them to go out and keep the community safe," Johnson said at a press conference after the incident.
"This is the worst outcome that could happen in this type of circumstance."
Johnson said he understood the pursuit was still in progress when the crash happened.
The authority and police are already reviewing police pursuits nationwide after a series of fatal crashes.
The review aims to understand pursuit environments and how police manage them.
On average, about 10 drivers flee police every day. Between October 2016 and September last year, seven deaths and 552 crashes were recorded.
The review will examine about 75 police pursuits which were reported to the authority last year, and a 10 per cent random sample of 200 other chases.
The report is expected to be released later this year.
Sunday morning's crash brings the weekend road toll to eight. Also, three people are in hospital with injuries after a crash in Northland.
A St John helicopter rushed to the scene in Ruakaka shortly before midnight and a crew treated the injured parties.
One person was critically injured in the crash, and two others had serious injuries.
One patient was airlifted to Auckland hospital and two others were flown to Whangarei Hospital.
A police spokeswoman said just one vehicle was involved in the crash, which happened on Peter Snell Rd.
The vehicle had driven off the road.
These crashes followed five earlier fatal crashes.
The first person killed was a man who died in a single-vehicle crash on Mountain View Rd in Hikurangi, Northland, just before midnight on Friday.
Two people received minor injuries.
Seven hours later two people died when a truck and a van collided in the central North Island at 6.40am on Saturday.
The crash happened at the intersection of State Highway 47 and SH48, the same place a bus crashed down a bank 14 months ago, injuring 14 tourists and the driver.
Two people died and a third was flown to Auckland Hospital in a serious condition after two cars crashed on State Highway 10 about 2.20pm, north of Kaeo, in the Far North yesterday.
When emergency services arrived at the crash, they found four people trapped — three in one vehicle, one in another.
