Transport for London to start automatically tracking bus passenger numbers

Transport for London (TfL) will soon start automatically tracking passenger numbers on buses in the capital using a mixture of CCTV footage, passenger Wi-Fi, and changes in weight and air pressure.

The three-month trial, starting tomorrow, is being rolled out across a handful of routes and, according to TfL, will assess which technique best captures passenger flow. This data could help the transport authority provide better real-time travel information and prioritise investment.

Seven buses on routes 55, 47, 222, 507 and 521 will be trialing the gamut of counting techniques, which range from cameras measuring footfall to special door sensors. TfL says the full list of technologies is as follows:

• Cameras aimed across the bus floor observing the footsteps of passengers getting on and off the bus
• Real-time analysis of existing safety camera footage
• Sensors over each door of the bus
• Analysis of changes to the buses weight and air pressure
• Passenger Wi-Fi connection data

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While records of changing bus weight certainly capture the imagination, privacy advocates are more likely to focus on the use of real-time CCTV analysis and Wi-Fi data. On the latter, TfL has previously tested the measurement of passenger Wi-Fi connections on the tube, similarly with the intention of monitoring passenger flow in its network.

TfL says that any Wi-Fi data collected during this new trial will be automatically depersonalised, in line with the Information Commissioner’s Office guidelines, and that no browsing data will be collected. Buses trialing the various counting techniques will also have posters to make passengers aware of what’s going on. A TfL spokesperson also told Alphr that no facial recognition would be used in the CCTV monitoring, and that the system would instead count “human shapes”.

Privacy advocacy group, Privacy International, told Alphr that the depersonalisation of Wi-Fi connections may not be as clear cut as TfL suggests: “Privacy International have previously warned Transport for London about the dangers of WiFi tracking on buses, due to the indiscriminate nature of such activity, and the inability to prevent capture of non-consenting users’ data,” said the group’s technologist, Christopher Weatherhead.

“One of the primary concerns is that depersonalisation of data does not mean anonymisation of data. Therefore information pertaining to an individual could potentially be inferred. Privacy International has broad concerns about the increasing prevalence of Wi-Fi tracking capabilities.”

Simon Reed, head of surface technology and data at TfL, noted that there are already a number of ways the transport authority monitors its passengers: “We use a range of methods, such as ticketing data and manual paper surveys, to understand how customers travel across London, but we cannot measure in real time the number of people on a given bus.

“We hope this trial will show us the best way to identify real-time bus usage, which in turn could help us plan our network better, run it more effectively and greatly enhance live customer information.”

Being able to see how busy buses are could make a nice addition to the ever-evolving toolkit of apps like CityMapper. TfL also claims that disabled passengers could have the most to gain from more accurate passenger monitoring, as it could make it much easier for them to tell how much accessible space is on any particular bus.