The Automobile Association (AA) says a 30km/h speed limit in Auckland city centre is a step too far.
AT says hundreds of deaths and serious injuries will be prevented if safe speeds are introduced across high-risk Auckland roads.
Auckland Transport (AT) yesterday confirmed it would consult early next year on the proposed changes to speed restrictions.
It yesterday announced its board had approved a Draft Bylaw, and would consult on it early next year.
Auckland Transport said the draft bylaw, which is part of AT's Regional Fuel Tax funded programme to improve road safety, would see speed limits reduced on 10 percent of Auckland's roads.
Between 2013 and 2017 there had been a dramatic increase in the number of speed related deaths and serious injuries, it said.
"Setting safe speeds is one of the quickest and most effective tools we have in reducing road trauma," said AT chief executive Shane Ellison.
"The public will now have their say on our safe speed proposals early next year, and for Auckland Transport to continue its work to make our streets safer for everyone."
If the proposal is adopted following consultation, AT would initially begin its Safe Speed Programme in the city centre, some town centres and approximately 770km of high-risk rural and urban roads around the region.
Infrastructure improvements will also be made to the roads subject to speed limit changes, to make road corridors and intersections safer.
Any proposed speed limit changes would come into effect later in 2019 following consultation in February and March, and adoption of the bylaw.
A survey of more than 14,000 AA members suggested 62 percent oppose or strongly oppose the idea of a 30km/h speed limit for the whole CBD, while 16 percent support or strongly support it. The remainder were undecided.
The AA said the number of responses were the most ever for an AA survey in Auckland.
"People see 30km/h as too slow to be credible on all but a very small number of CBD roads, and they're not at all comfortable with that becoming the default limit for the whole area," spokesperson Barney Irvine said.
The AA would be pushing for reductions to 40km/h instead, he said.
"The Transport Agency's tool for setting speed limits, the Speed Management Guide, recommends 40km/h as the safe and appropriate speed for the bulk of roads in the CBD, but AT is choosing to ignore it," he said.
"We think an approach based on 40km/h would be a win for road safety and a win for public support.
"Sydney and Melbourne have both moved to 40km/h CBDs to good effect and we've seen it work well on Ponsonby Road here as well."
The AA is also questioning whether any speed limit reductions make sense on multi-lane arterial routes such as Hobson Street, Nelson Street and Fanshawe Street.
"Telling people to drive at 30km/h on wide, expansive roads that have a natural driving speed of 50km/h just won't work - all that's likely to happen is that people drive above the limit at the speed that makes sense to them," he added. "Before looking at lowering the speed limit, we want to know what engineering work can be done to improve the roads so they're safer for everyone at current speeds."
The survey suggested AA members had similar reservations about changes proposed for town centres and rural roads.