SunLive - Does lower speed limits equal reduced emissions? sunlive.co.nz - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from sunlive.co.nz Daily Mail and Mail on Sunday newspapers.
Waka Kotahi says it's lowered speed limits to 80 kilometres per hour on about four percent of New Zealand highways as part of the Road to Zero safety campaign.
The changes have frustrated many drivers, and the incoming National government has been vocal in their criticism, too.
But the lower speed limits don't only make our roads safer - they can have big emissions benefits.
Morning Report producer Emma Ricketts has more.