The NSW government could block a council-led plan to further cut speed limits in Sydney's centre, a move the premier says could reduce metropolitan traffic to walking speed.
All roads in the City of Sydney council area - which covers the main business district and several inner-city suburbs - will be limited to maximum speeds of 40km/h in the coming weeks.
Roads outside council control, like motorways and major thoroughfares, will remain above the speed limit.
But the council has flagged working with state officials to lower speeds on those roads as well.
The council also wants to limit traffic to 30km/h on more roads in the city centre and other high-pedestrian areas.
Premier Chris Minns said increasing the number of 30km/h roads was over the top, adding: "You could walk quicker than that."
The centre of Australia's most populous city shouldn't be treated as if it were a country town, he told reporters on Wednesday.
"It's got broader obligations than just those people that live and pay rates within its boundaries ... it's a major international city," Mr Minns said.
In announcing the change on Tuesday, Sydney Lord Mayor Clover Moore said speed limits of 40km/h or lower would drastically improve survival rates for people hit by a vehicle.
"It is everyone's responsibility to make our roads as safe as they possibly can be for people walking, riding and driving," she said.
Two decades ago, only five per cent of the council's roads had a limit of 40 km/h or lower.
Now three-quarters do and more will be added within weeks.
"Not only will our streets be safer as a result of these important changes, they'll be quieter and have less exhaust emissions," Ms Moore said.
A Transport for NSW spokesman said the agency assesses local and regionals roads at the request of councils.
"Speed limit zones across NSW are constantly reviewed and assessed according to factors including crash profile, road function, road use, roadside development, road characteristics, traffic mix, crash history and the presence of vulnerable road users such as pedestrians and bicycle riders," they said.
Business Sydney executive director Paul Nicolau said more consultation was needed on the council's pursuit of a 30km/h speed limit.
"Unreasonably low speed limits run the risk of stifling the commercial life of the city, which is already struggling to recover," he said.
"The lack of consultation about this latest change and the apparent wider agenda are a serious concern."
The business lobby group called on Roads Minister John Graham to intervene, asking for a suspension of speed-limit changes to allow for more consultation.
"We believe the government is in a position to intervene as the council's announcement says the speed limit change is being funded by the government," Mr Nicolaou said.
Mr Minns said he would speak to Mr Graham about "common-sense laws" for the city.
The council has previously advocated for a range of changes to car traffic through the city, including the pedestrianisation of George Street following the construction of a light-rail line.
Traffic lanes have also been removed on several streets to allow for the construction of bike lanes.
