A study of police chases has found Wales' four forces have significant differences in when and how they would pursue a suspect vehicle.
Differences were found in the way Welsh forces made pursuits
The research discovered that in the majority of cases the forces had no plan to ensure a car chase ended safely, and in many cases officers were not properly trained.
North Wales Police had a leading role in the year-long study by the Police Complaints Authority (PCA), which has described the number of deaths caused by police pursuits in England and Wales as unacceptable.
The authority found that more than half of pursuits conducted by the north Wales force ended with a collision, compared to just under 13% in those by its south Wales counterparts.
One person was killed and 48 injured in police pursuits in Wales in the 12 months between September 2002 and August 2003, the PCA study found.
Across England and Wales, more than 1% of all traffic fatalities between 2001 and 2002 involved the police.
So far this financial year, 27 people have died in police chases, compared with 31 last year and just eight deaths between 1997 and 1998.
The study found more than half of pursuits had no plan to end them
Almost 350 officers provided information to compile the Welsh forces' study, Police Pursuits in Wales, published with another report, Following Fatal Pursuit.
The report found less than half of incidents assessed had a plan to end the pursuit safely - most commonly through using a "stinger" device or helicopter - but the plan worked successfully in only 6% of cases.
The PCA said it was "worrying" that 21 incidents in Wales were undertaken by drivers trained only to standard or basic level.
It said that was "a situation that should only occur in the gravest of circumstances."
There were also sharp differences in the speeds achieved during police chases or "follows" and the outcome of the pursuits, the report found.
Arrests were made in just over 40% of all of the incidents, with a total of 226 people arrested immediately and a further 42 arrested subsequently.
The average estimated maximum speed in North Wales Police incidents was 73mph compared to 53mph by South Wales Police.
The average length of pursuits was longer in the North Wales force and Dyfed-Powys Police areas than in the other forces area - more than seven minutes - compared to 5.8 minutes in Gwent and 4.9 minutes in south Wales.
Both North Wales Police and Dyfed-Powys Police averaged more than one arrest for each incident, while South Wales Police averaged just over one arrest for every two pursuits reported.
But the north Wales force also recorded the highest injury rate - an average of 0.37 injuries per incident.
Overall, it found the North Wales Police force had more arrests but speeds were on average higher, the number of collisions greater and the force had the highest statistical rate of injuries.
Sir Alistair Graham, Chairman of the
Police Complaints Authority, said: "Our key recommendations are that police forces must
have properly considered policies in place regarding the pursuit of vehicles and
"Secondly, they must have a range of suitable tactics to lead to the safe conclusion of such pursuits."