London 20mph speed limits have more than tripled on roads controlled by Transport for London (TfL) since 2021, according to newly released figures.
Data obtained through Freedom of Information laws shows that around 50 miles of TfL-controlled roads had a 20mph limit in 2021. By March this year, that figure had risen to 166 miles, figures first reported by Regit on 15 September 2026 show.
The increase means that almost half of the approximately 360 miles of highways controlled by TfL across Greater London are now subject to a 20mph limit.
Vision Zero programme
The figures come as London Mayor Sadiq Khan continues to expand his Vision Zero programme, which aims to eliminate deaths and serious injuries on the capital’s roads. TfL’s wider record on road safety has also come under scrutiny, including its prosecution over a fatal bus crash in Walthamstow.
TfL points to its own research as justification for the lower limits, which it says shows that 20mph schemes have contributed to a 34 per cent reduction in the number of people killed or seriously injured on borough roads following their introduction. A TfL spokesperson told Regit that “its evidence shows that 20mph speed limits save lives, pointing to research showing a 34 per cent reduction in people killed or seriously injured on borough roads after 20mph schemes were introduced.”
Drivers voice concerns
The policy remains controversial among motorists. Critics argue that 20mph limits are increasingly being introduced on roads where they believe higher limits would be appropriate, and that the growing patchwork of lower speed zones can make it harder for drivers to know which limit applies when travelling between different parts of the capital.
Most of the roads that have been reduced from 30mph to 20mph were previously subject to the higher limit.
The growth in 20mph zones has coincided with a sharp rise in speeding detections. Figures obtained from police forces earlier this year showed that 21,125 motorists were caught by speed cameras in 20mph zones across the country in 2023, rising to 127,915 in 2025, with data from 22 police forces showing almost 250,000 motorists caught speeding in 20mph areas during the period covered.
Wider changes for London drivers
The expansion of 20mph zones is one of several changes affecting drivers in the capital under Mr Khan, alongside the expansion of the Ultra Low Emission Zone across Greater London in 2023 and the increase in the Congestion Charge. London’s taxi trade is also under pressure, with the LTDA and Freenow calling for a temporary suspension of the taxi age limit amid fears of a black cab shortage.
TfL has also seen a sharp increase in revenue from bus lane enforcement, reportedly collecting £6.6 million from 54,761 motorists issued penalties for entering bus lanes last year, up from £4.3 million and 29,423 drivers the previous year.
Mr Khan’s transport agenda continues to evolve elsewhere too, with TfL recently rejecting a Superloop SL4 extension to Bromley North. The wider debate over 20mph limits is likely to continue as more roads adopt lower speed limits.
