Transport For London (TfL) will soon collect depersonalised wifi data from commuters connected to wifi at 260 of its stations. The anonymised data will help TfL understand how people move through the system and will eventually inform real-time traffic updates and advertising.
Although the data will not drive digital advertising, it will aid with reporting impressions of, and footfall near, its vast physical advertising real estate.
Currently, the ticketing system tracks the entry and exit from the tube, but not the minutiae of the journey itself. But from 8 July, wifi tracking will be implemented to understand flow of commuters, congestion and provide more accurate advice and alerts to those in the system.
It said that no browsing or historical data will be collected from any devices. TfL said it worked closely with the Information Commissioner's Office to develop the system.
Lauren Sager Weinstein, chief data officer at Transport for London, said: “The benefits this new depersonalised dataset could unlock across our network — from providing customers with better alerts about overcrowding to helping station staff have a better understanding of the network in near-real time — are enormous.
“By better understanding overall patterns and flows, we can provide better information to our customers and help us plan and operate our transport network more effectively for all.
“While I am excited about the potential of this new dataset, I am equally mindful of the responsibility that comes with it.”
It comes after a four-week test in 2016 across 54 stations. During that window, more than 509m depersonalised pieces of data were collected from 5.6 million mobile devices (more than half the population of London).
These 42 million journeys "revealed a number of results to TfL that could not have been detected from ticketing data or paper-based surveys," the company said.
One insight was as follows: "For example, analysis showed that customers travelling between King's Cross St Pancras and Waterloo take at least 18 different routes, with around 40% of customers not taking one of the two most popular routes."