Community calls for lower speed limits have triggered reductions for some roads in western Christchurch.
The Transport Agency says the changes will affect roads around the Yaldhurst area, where there has been significant development.
The lower speed limits will be on State Highway 73, east and west of Yaldhurst.
Maximum speeds will also be cut on the section of the highway going through the suburb.
And the Christchurch City Council will lower the speed limits on Pound Road and Ryans Road.