"Switching on the first of the new cameras is an important milestone in our efforts to reduce deaths and injuries on the country's roads, as part of the wider Safer Journey's strategy which focuses on creating safer roads and roadsides, safer drivers and promoting safer vehicles," Assistant Commissioner of road policing Dave Cliff said.
"Between 2010 and 2012, driver speed contributed to approximately three out of 10 of all fatal crashes, and two out of every 10 serious injury crashes. In human terms, that translates to 299 people killed in speed-related crashes over that three year period, and a staggering 6300 people who suffered some kind of injury, ranging from minor to very serious."
Research in New Zealand and internationally showed speed cameras encouraged motorists to slow down, he said.
The current fixed camera network is almost 20 years old and uses outdated wet film technology. The new cameras are digital and use 'second generation' technology.
The first 12 sites to have them installed would be a mix of existing and new locations, Mr Cliff said.
In September a second site will have a new camera installed, in Wellington's Wainuiomata Road.
The $10m funding for the speed camera upgrade project was provided by the New Zealand Transport Agency through its road policing programme, with both the police and NZTA to share ongoing operating costs.
All money collected from speeding infringements went to the Government, not police, Mr Cliff said.
Location of first 12 new sites for fixed speed cameras
*Indicates existing
State Highway, Ngauranga*
Wainuiomata Road, Wainuiomata
Whitford Brown Avenue, Aotea
State Highway 1, Thorndon*
Wainui Road, Waiwhetu
Hutt Road, Korokoro
Great South Road, Otahuhu*
Mill Road, Totara Park
Murphys Drive, Totara Park
Tamaki Drive, Parnell
Candia Road, Henderson Valley
Great North Road, Kelston*