The speed limit for traffic on Blackfriars Bridge and London Bridge will be reduced to 20 mph from Sunday 20 July, the City of London Corporation has confirmed.
The City of London Corporation will introduce a 20 mph limit on nearly all its roads in the Square Mile next month.
At the same time, Transport for London is lowering the speed limit on Blackfriars Bridge and London Bridge.
The Blackfriars 20 mph trial is linked to plans for a new north-south cycle superhighway between King's Cross and Elephant & Castle.
Last year Transport for London revealed that bicycles make up more than half of all northbound traffic crossing Blackfriars Bridge during the morning peak hours.