"There's no other way to put it. If they have a crash at that speed they're going to die. And they're putting other people at risk at the same time.
"The law of physics apply. If you crash at that speed, it's not going to be the car stopping that kills you. It's going to be when your brain impacts the front of your skull, basically."
The top speed recorded in the last three and half years was 194km/h on Stage Highway 8 at Lake Tekapo in 2008, though police believe faster speeds have been measured by hand-held radars. In 2009 a vehicle was caught travelling 109km/h over the 60km/h limit.
Automobile Association (AA) driver training manager Karen Dickson said a driver's hazard detection at more than 100km/h became increasingly difficult because at that speed peripheral vision was reduced to around 8 per cent.
"At 189km/h your chances of picking up an item or something in front, on a side road, is negligible. They are seeing less than 10 per cent of what they should see at that stage, which is frightening."
AA calculated that in the last 5m before stopping, a car still held 25 per cent of its speed.
So even if a car travelling 189km/h had slowed down to avoid a hazard, it would still be carrying around 47km/h of speed a moment before it stopped.
"If you hit a kid at 50km/h, they've got around a 70 per cent chance of surviving. If you hit them from 80km/h upwards, there's almost zilch. So at 190 kilometres ... the survival rate is terrible, non-existent," she said.
Mr Morgan said only 6 per cent of drivers exceeded the speed limit by more than 10km/h, but they were "very high risk".
HIGHEST ON SPEED CAMERA
Fastest speeds recorded in Jan-April 2011:
* 189 km/h (speed limit 100km/h) - April 22, SH2, Lower Hutt between Melling Link Rd and Koro Cres
* 181km/h (speed limit 100km/h) - March 3, SH2, Lower Hutt between Kennedy Good Bridge and SH58
* 179km/h (speed limit 100km/h)- January 1, Eltham Rd between Patiki and Auroa Rds
* 177km/h (speed limit 100km/h) - January 6, SH1 Porirua between Paremata Bridge and Mungavin Overbridge
* 174 km/h (speed limit 100km/h) - January 22, SH6, Nevis Bluff between Victoria Bridge and Church Lane.