Supt Greally said attending accident scenes was hard for everyone involved.
"(Taupo) was a horrific scene for officers and ambulance staff, tow-truck drivers and undertakers," he said.
"You couldn't write a script of more horror and it's worse to knock on the door of families. It's hands down the toughest job in New Zealand."
It's not yet known if speed is behind the fatal crashes this past week, as investigators work to determine the causes.
"The bottom line is decision-making from our drivers - this problem won't go away until this country understands that this is a really serious problem," Supt Greally said.
"Not one death is acceptable, that's our view."
The national road toll for the year stands at 296, 44 greater than at the same time in 2016.
ROAD FATALITY STATISTICS FOR 2017 SO FAR
• 159 driver deaths
• 62 passengers
• 30 motorcyclists
• 31 pedestrians
• 15 cyclists
(Source: Ministry of Transport)
- NZN