Safety stickers are appearing on platforms at busy Underground stations following complaints of dangerous overcrowding.
Tube bosses were criticised earlier this week after passengers were unable to practice social distancing during the rush hour.
Cuts to the timetable caused by staff shortages led to alarming scenes at North Acton station, west London, where commuters were forced to change trains and waiting on crowded platforms.
The new blue stickers are spaced two metres apart to allow passengers to stand a safe distance from each other.
Frequent station announcements are being made to advise passengers to comply with the social distancing rule. Tube trains are now disinfected every day.
Transport for London said the number of people using the Underground has dropped by 95%
Around 200,000 journeys were made on the Underground on Wednesday compared to 3.98m on the same day in 2019
TfL said 160,000 Oyster and contactless cards were used on London’s Tube and rail network on Wednesday
Around 2m individual cards were used to tap in and out at stations before the coronavirus outbreak
Shuttle trains on the West Ruislip branch of the Central Line have been replaced by through trains during the morning rush hour so commuters can avoid changing at North Acton.