A change to some of the speed limits in Auckland will make a big difference to the city.
Most speed limits will go down from 50 kilometres per hour to 30 on more than 600 roads across Auckland today, including the central city.
Infrastructure transport expert Fergus Tate told Mike Hosking the goal is to reduce the number of crashes on the roads.
“The social cost of crashes in New Zealand is in the billions, and again, it depends whose loved one gets killed or seriously injured, but this will make a big difference."
There are concerns lower speed limits in Auckland will cause more traffic congestion, but Tate says city traffic jams have many other reasons for happening.
“The amount time it takes to get from one place to another is driven more by the amount of traffic signals in the area than the speed limits."