A 15mph speed limit is set to be introduced in an area of the UK for the first time.
The City of London Corporation has voted to enforce the measure across the Square Mile in a bid to reduce the likelihood and severity of collisions.
It says its “radical” transport strategy to lower the existing 20mph limit will prioritise the needs of pedestrians and cyclists.
The local authority wants to “make the most efficient use of street space” and reduce traffic by a quarter by 2030.
The new speed limit could be enforced by 2021/22 if it is approved by the Department for Transport (DfT).
Alastair Moss, chairman of the planning and transportation committee at the City of London Corporation, said: “We are working tirelessly to support the 513,000 workers that commute to the Square Mile every day, and to deliver the forward-thinking City that Londoners want to see.
“These radical plans will ensure the continued success of not just the City, but wider London and the UK as a leading global business and cultural destination.”
AA president Edmund King said switching the limit from 20mph to 15mph is “not likely to make much difference” as traffic in the Square Mile has “moved no faster than a horse and cart for 100 years anyway”.
He added: “All road users and pedestrians being more alert, abiding by the rules of the road and putting away their phones would probably be more effective than reducing the limit.”
The City of London Corporation reported that its ban on traffic at Bank junction between 7am and 7pm on weekdays – except buses and bicycles – has halved casualty numbers since it was introduced in May 2017.
A DfT spokeswoman said: “We are proud that the UK has some of the safest roads in the world but we are always looking at ways to make them safer.
“We await the application from the City of London Corporation and will respond in due course.”