Transport for London says it intends to introduce a 20 mph speed limit for all traffic at the BFI IMAX junction at Waterloo on an experimental basis for six months.
Transport for London says that counts show that more than 5,500 cyclists use Waterloo roundabout each weekday, representing nearly a quarter of all traffic at the junction.
Last year TfL announced a series of changes to the junction to improve safety for cyclists.
TfL is proposing to introduce a 20 mph speed limit on the roundabout and the approach roads as a six-month experiment to assess the benefits and impacts on all road users.
TfL is holding a public consultation on the proposed experimental speed limit which runs until the end of February.
Work is due to start in late March.