London Tube to track phones using Wi-Fi

LONDON: Transport for London (TfL) will begin tracking customers’ phones on the London Underground by default from July 8^th onwards. Wi-Fi access points covering 260 of London’s stations will be tracking customers through their phones’ Mac addresses, providing TfL with data like the routes passengers take throughout the network and individual stations they pass through.

The systems’ reliance on MAC addresses which are automatically sent to Wi-Fi access points whenever a phone tries to connect, indicating that, to avoid this system, your phone’s Wi-Fi must be entirely shut off.

However, TfL has reassured customers by stating that no browsing or historical data from devices will be collected, and the data that is collected will be anonymised. This means TfL will tokenise MAC addresses, therefore replacing them with an identifier which cannot be linked back to any specific smartphone and therefore the customer.



This modification simply serves to allow TfL a better understanding of how the Tube network is used on a day to day basis and provide improved real-time information about crowing levels in stations. While TfL can already use ticket data to determine which stations people are travelling between, this tracking can provide London Underground staff with the ability to advise people on the best, most convenient way to reach their destination.

This will also allow TfL to issue accurate, real-time crowd warnings on their website and social media. More significantly, crowd data will also be provided via the authority’s existing APIs, which potentially could allow mapping companies like Google Maps and Citymapper to assist users in avoiding areas of high congestion and provide optimal transport recommendations.

TfL alleges these adjustments may benefit advertising space by “highlighting the effectiveness and accountability of its advertising estate based on actual customer volumes.” Advertisers with the goal of reaching a large number of people could utilize data such as the number of people in corridors of stations, and how many people will see the advertisements where they are placed.

TfL claims to have worked closely with the Information Commissioners’ Office (ICO) on the enactment of the scheme, adding that their MAC-anonymising solution has received the regulators’ full approval. Customers will be informed about the tracking program via signs erected around stations.

Back in 2016, TfL conducted a short pilot study over a period of four weeks. According to them, 509 million individual data points were collected from 5.6 million mobile devices travelling as part of 42 million journeys. By making the scheme permanent, TfL will collect billions more.

This story originally appeared on The Verge.