In an experiment across 52 underground stations in the capital, Transport for London (TfL) tracked smartphone users via their devices.
Last year from the 21st November to 19th December, the government body noted the movements of anyone who had their Wifi connected during a tube journey.
It’s important to note that that TfL were transparent about the whole experiment, as the only data they recorded was the location of users on the tube. All information was encrypted, with the purpose of the test being to understand the routes Londoners took on their journeys.
Interestingly, the tracking helped to suggest the popularity of Virgin Media’s free underground Wifi. According to TfL’s analysis of Vauxhall station, Wifi traps picked up a third of devices entering the station. However it could be the case that many users are simply walking around with their Wifi on, connecting to different networks.
One of the things TfL were trying to work out is why we take the routes we do. For example, when travelling from Liverpool Street to Victoria, the most popular route involved a change at Oxford Circus to use the Victoria Line, rather than remaining on the Circle Line. 44% of people made the switch, while just 26% remained in their seat.
Previously this data was only tracked by journeys made on a particular Oyster card, but the Wifi tracking allows TfL to analyse the finer details.
A spokesperson for TfL told Gizmodo: “By using Wi-Fi data, merged with aggregated Oyster and Contactless ticketing data we would have a far richer data source to ensure optimal and evidence based decision making for a wide range of planning decisions.”
Another reason for the experiment was undoubtedly the advertising potential of tracking our movements underground. Knowing exactly where passengers are at certain times could be invaluable to advertisers, with the data helping to determine where the next digital displays will go and how long each ad will last for.
TfL appear to still be assessing the data, so it is likely more may be released soon. If successful, it’s possible that this kind of Wifi tracking could become the norm in London.