The plan proposed a swathe of other changes for coming years, including dropping speed limits around schools and roads deemed unsafe, and increasing penalties for risky driving.
Changes are also coming for speed cameras, with Genter saying by mid-2021 they would be heavily signposted to try to get people to slow down.
"They're going to be very highly signposted. The idea and philosophy which has been proven to work overseas is you use the cameras on speed cameras to ensure people are driving at safe speeds," Genter told reporters.
"In an ideal world we won't collect a single infringement fee."
Responsibility for speed cameras will also move from police to the NZ Transport Agency (NZTA), in a bid to reduce back-office work.
But Genter said the NZTA wouldn't receive any of the revenue from the cameras, and police could still continue to use other kinds of speed cameras, such as in vans.
The Government put the plan out to consultation in July and Genter said about a third of people felt the 40 per cent reduction target didn't go far enough.
"It's right to take the approach that no loss of life on our roads is acceptable, but we need to be hard-headed and evidence-based about how we're going to get there," she said.