Passengers on the Victoria, Northern and Jubilee lines are being exposed to "dangerous levels" of noise, with the notorious "tunnel screech" reaching more than 100 decibels (dB) – louder than a nearby chainsaw or power tool.
Data released by Transport for London (TfL) and the Mayor of London's office last month shows the network received 707 noise complaints over the past three years, including 641 relating to noise inside Tube carriages and 66 at stations.
Loudest and quietest lines
TfL measures sound exposure in carriages by calculating the average noise level over a specific period on each line. Commuters on the Northern line faced levels of up to 104 dB in the worst periods, while the Victoria and Jubilee lines recorded 102 dB.
The Hammersmith and City line was the quietest on the network, with a maximum average noise level of 81 dB, comparable to a hair dryer or vacuum cleaner. It also recorded the lowest average noise levels overall.
Concerns over passenger conditions
Elly Baker, Labour's transport spokesperson on the London Assembly, said: "Passengers should not have to put up with excessive noise every time they travel on the Tube.
"TfL's own data shows noise is reaching dangerous levels in parts of the network. This raises serious questions about the conditions passengers are travelling in.
"Despite years of complaints, there is still a lack of clear information about why some parts of the network are particularly noisy and what steps are being taken to address the problem.
"TfL needs to be transparent with passengers about the causes of this excessive noise and publish a clear plan to reduce it."
TfL response and mitigation
TfL said it "recognises the importance of reducing the impact of noise on customers". In July, London mayor Sir Sadiq Khan said the main cause of track noise was "rail corrugation", where a bumpy pattern forms on the train tracks due to friction over time.
He said he has set aside £9 million for "rail grinding" work to help mitigate this. In a written answer to the London Assembly about the causes of the noise, the Mayor said: "There are a range of factors that contribute to noise levels inside London Underground carriages.
"These include the track curvature, the speed of the train, whether automatic train operation is in place, the spacing and condition of the sleepers, and the overall track form."
