TfL and Mobile Phone Data

MQT on 2017-10-12
Session date: 
October 12, 2017
Question By: 
David Kurten
Asked Of: 
The Mayor


I was somewhat perturbed to read in the Evening Standard on 28 September 2017 that during a four-week trial before Christmas last year, TfL followed the mobile phones of some 5.6 million passengers, to allegedly identify what passengers were doing at various points in their journey, such as entering or exiting a station, or changing lines. I understand that TfL is currently considering a full-scale roll-out of data collection from passenger's mobile phones. What is TfL going to do with all this data and what consideration is being given to the fact that many commuters will be uncomfortable with their data automatically being harvested by TfL, as they go about their business.


Answer for TfL and Mobile Phone Data

Answer for TfL and Mobile Phone Data

Answered By: 
The Mayor

TfL is committed to being open and transparent about its use of data.

Prior to the trial last year, TfL considered guidance from the Information Commissioner's Office (ICO) on WiFi location analytics and the ICO's Code of Practice on Privacy notices, transparency and control. In addition, TfL met with the ICO to outline its approach during the planning stages of the pilot.

The four-week TfL pilot, which ran between November and December last year, studied how depersonalised WiFi connection data from customers' mobile devices could be used to better understand how people navigate the London Underground network, allowing TfL to improve the experience for customers.

TfL adopted the ICO's advice to inform customers that it was collecting WiFi data and the benefits from doing so. TfL updated customers about this activity using in-station posters, press releases, a Metro newspaper article, social media, and a dedicated webpage and told customers they could opt-out by switching off their WiFi.

TfL's practice during the trial was praised by both the Information Commissioner and Big Brother Watch at the GLA Oversight Committee in September.

TfL published its findings from the WiFi on their website, the link to which is here: The findings show the potential value of the information for customers and for TfL's operations and commercial revenues.

The trial showed that TfL is justified in looking for benefits to customers and its own operations through WiFi data and any future data collected will fully comply with data protection legislation and best practice.