Cameras would be mounted on the poles from next year.
The programme would eventually see up to 56 fixed cameras placed at high risk sites across the country, with 15 already in place.
Site works for the 33 sites were announced in May, and represent the third phase of a speed camera expansion programme announced in 2013.
Greally said poles and cameras would be put on roads identified as having a high crash risk based on detailed analysis by independent traffic experts, taking into account the history of fatality and injury crashes.
"We know from international experience that speed cameras do have an impact on slowing people down, particularly around the sphere of influence of the camera.
"This is why we are placing fixed speed cameras at this and other sites to encourage people to reduce their mean speeds, which, when coupled with road safety improvements and other measures, helps to reduce deaths and injuries," said Greally.
As well as cameras police would continue to have a visible presence on high risk routes.
New fixed speed camera locations:
Old North Rd, Kumeu, Waitemata
Twin Coast Discovery Highway, Kaiwaka, Northland
Tamaki Drive, Parnell, Auckland City
Hillsborough Rd, Hillsborough, Auckland City
Great North Rd, Grey Lynn, Auckland City
State Highway 2, Pukehina, Bay of Plenty
State Highway 1, Temuka, Canterbury
Leeston Rd, Springston, Canterbury
State Highway 3, Mokoia, Central
State Highway 56, Tiakitahuna, Central
Mahia Rd, Wattle Downs, Counties Manukau
Massey Rd, Mangere, Counties Manukau
Waiuku Rd, Mauku, Counties Manukau
Glenbrook Rd, Kingseat, Counties Manukau
Awhitu Rd, Karioitahi, Counties Manukau
Great North Rd, Kamo, Northland
Southern Motorway, Burnside, Dunedin
King Edward St, South Dunedin
Otatara Rd, New River Ferry, Southern
Serpentine Ave, Dunedin Central
Severn St, Oamaru
State Highway 2, Maramarua, Waikato
State Highway 2, Waikino, Waikato
Main Rd, Raglan, Waikato
State Highway 29, Te Poi, Waikato
Otorohanga Rd, Otorohanga, Waikato
State Highway 2, Waihi, Waikato
Te Awamutu-Cambridge Rd, Cambridge, Waikato
Coatesville Riverhead Highway, Coatesville, Waitemata
State Highway 1, Wellsford, Waitemata
State Highway 17, Albany Heights, Waitemata
Great North Rd, Henderson, Waitemata
Twin Coast Discovery Highway, Dome Valley, Waitemata
Rata St, New Lynn, Waitemata
East Coast Rd, Redvale, Waitemata