KEY POINTS:
New road spikes are expected to be on hand in 1200 more frontline police cars within months following successful trials in Auckland of new gear intended to make car chases safer.
The new "stinger" spikes have shortened the time it takes police to lay spikes, which they say
is stopping offenders earlier and thus lowering the risk to members of the public who get caught up in pursuit-related dangerous driving or crashes.
National road policing manager Superintendent Dave Cliff told the Herald the new spikes - used successfully by police in the United States and other countries - were lighter, easier and faster to deploy.
They replaced spikes that needed to be pinned down, dragged across a road and then pinned down again.
Officers using the new spikes simply had to throw them across a road, making the process safer and faster, he said.
The new spikes worked by triggering a "controlled deflation" of a car's tyres, which meant tyres were let down slowly, reducing the risk of crashing afterwards.
"It's another tool that we have to stop people safely who refuse to drive safely," Mr Cliff said. "The whole point is it's a last resort."
A review of police policy on car chases is under way after several pursuits ended in crashes.
Mr Cliff said it was important police were not in a position of having to back off from chases, which would give offenders freedom to flee.
"The vast majority are stopped because they're driving dangerously in the first place and that's why police are trying to stop them. If we don't stop people who are driving dangerously and let them continue on, the risks around that are enormous," he said.
"We swear an oath to protect life and property. We can't back away from the oath."
Inspector Rob Morgan of police national headquarters said the Counties Manukau trial showed the benefits of having more patrol cars carrying spikes, with officers reporting shorter chases before catching offenders.
More than half of the country's 3000 frontline cars will have stinger spikes when the new order arrives next year.
ROAD WORKS
* Police trialled 100 stinger spikes in Counties Manukau from September 2004 until December 2005.
* They later ordered and received another 550. Another 1200 have been ordered from an American manufacturer and are expected to come in lots of 500 within the next few months.
* Police have about 3000 frontline vehicles including booze buses and marked and unmarked patrol cars.