New speed limits across more than 600 roads in Auckland come into force from tomorrow.
There will be lower speed limits for Auckland's city centre and on some roads in the Rodney Local Board and the Franklin Local Board areas.
Most speed limits in the CBD will drop from 50 to 30km/h, except for Nelson, Hobson and Fanshawe Streets which will have 40km/h, and some shared streets such as Federal St, which will have a 10km/h limit.
Auckland Transport chief executive Shane Ellison said 40 people died and 567 people were seriously injured on the area's roads last year.
He said while Auckland's roads did need work, speed played a significant role in the severity of crashes.
"When a crash does happen, you're more likely to survive if you're driving at a safe speed," he said.
"We want you to be able to walk away from a crash, no matter what the cause. Even when speed doesn't cause the crash, it is the single biggest determinant in whether anyone is killed, injured or walks away."
Auckland Transport's head of safety Bryan Sherritt said the aim was to reduce deaths and serious injuries on roads.
"It's one vital piece of the puzzle in our road safety jigsaw. Speed doesn't cause every crash, but it does determine whether someone walks away from the crash or not," he said
Councillor Chris Darby said too many people died on Auckland roads in avoidable tragedies.
"[Those] precious lives being extinguished is something we need to see the back of."
He said a council review of the Auckland Plan 2050 prompted the changes.
"We realised that we were failing miserably to provide a transport system that maximised safety for all."
He said there had been an increase in traffic-related deaths and injuries, particularly for vulnerable road users.
The council acknowledged that drivers made mistakes and was seeking to minimise harm from people making those mistakes, Darby said.
You can see a detailed breakdown of the new limits here.