Police are justifying why they've placed three speed cameras on the Wainuiomata Hill.

Concerns have been raised by Lower Hutt mayor Ray Wallace over the installation of two new cameras, one at the top and one at the bottom of the hill.

That adds to the already existing camera on Wainuiomata Hill road.

In a statement released today, Police say the sites were carefully chosen after a rigorous site selection process.

National manager road policing Superintendent Carey Griffiths says they consulted with Hutt City Council safety engineers as part of that process who raised no issues.

He says he'll contact the mayor to discuss any further questions he has.