The Independent Police Conduct Authority has questioned whether some police car chases are worth the risk they pose to the public and has recommended several changes to policy.
The IPCA reviewed 137 car chases since December 2003. It says most cases began over traffic violations and few uncovered evidence of serious crimes other than an offender's driving during a chase itself.
The authority says officers need clearer guidelines about when to start a chase and their decisions should not be based on speculation about why a driver has not complied with a police request to stop.
In the five years reviewed, 24 people died and 91 received serious injuries in police chases.
IPCA chairperson Justice Lowell Goddard says some pursuits began over general suspicions or minor offences, where the benefits of a chase outweighed the risks.
The judge says the decision to begin a chase should be based on known facts, rather than speculation about a driver's reasons for not stopping. She says they may be committing minor traffic offences and panic when confronted by police.
Justice Goddard says the major consideration for officers should be the risk to public safety if an offender is not stopped.
Police say the public's safety is always a priority when officers decide whether to begin a vehicle pursuit.
Assistant Commissioner Viv Rickard says police will consider the IPCA recommendations as part of an internal review already under way.
Mr Rickard says there were 12,000 police chases in the period concerned.
About a quarter of people involved with pursuits are in stolen vehicles and are young men who are driving dangerously, he says.
