Why is Transport for London going to track my data?

From early July 2019, London’s transport network, TFL, has announced it will be collecting data from devices that log-on to the Wi-Fi by default, in a bid to understand how people use the tube. Wi-Fi access points across 260 of the capital’s stations will track customers using their phones’ MAC addresses; when a mobile device such as a smartphone or tablet has Wi-Fi enabled, the device will continually search for a Wi-Fi network to connect to. When searching for a Wi-Fi network, the device sends out a probing request that contains an identifier specific to that device, known as a Media Access Control (MAC) address. If the device finds a Wi-Fi network that is known to the device, it will automatically connect to that network. If the device finds unknown networks, it will list these in your device settings so you can decide whether to connect to one of them.

MAC addresses will be tokenized, meaning they will be replaced with an identifier that can’t be traced back to a smartphone or the customer who owns it. That way data will automatically be depersonalized. TFL will not collect any browsing or historical data from devices.

The privacy campaign group Big Brother Watch has expressed concern about data being collected without consent. However, TFL has worked with the Information Commissioner’s Office to address privacy and transparency concerns. Signs will be erected around the tube network, similar to existing CCTV warnings, to inform customers about the tracking program.  The only way to opt out of this system will be to turn your phone’s Wi-Fi off entirely while travelling.  

By collecting the data, TFL has said it is hoping to improve passenger journeys by getting a more accurate understanding of how people move through stations, interchange between services and how crowding develops.

The data is to be used to offer targeted, helpful information to passengers. For instance, it could tell commuters how busy incoming trains are, so they could plan their journeys accordingly. Moreover, the information could be used to support station expansion plans, provide regular real-time posting on social media feeds and to reduce the number of incidents taking place on the tube network.

Data will also be made available to app developers, academics and businesses to create new products and services, ultimately helping passengers to have a more comfortable journey.

It’s not clear whether other major cities around the world will follow suit, but it is seen as a step forward in using data for positive means and creating comfortable, safe passenger journeys.