Drivers will have to detour around the intersection of Hyde Park Road and Sunningdale Road West for the next few months.
Construction of a new roundabout at the northwest London intersection is scheduled to begin on Monday.
"As part of this project, crews will be converting the intersection into a multi-lane roundabout to improve mobility and safety for all road users while helping to accommodate future travel demand," the city said in a statement.
The Hyde Park and Sunningdale roundabout is among the city's top ten construction projects this year.
Signage has been erected to help drivers and cyclists detour around the road work.
The construction is expected to be completed in the fall with finishing touches planned for 2022.
