Our Ref:         FOI-2185-2021

Thank you for your request received on 28 January 2021 asking for information about the Wi-Fi available on the London Underground.

Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy. I can confirm we do hold the information you require. You asked for:

SHEET 1: The top ten most popular (frequently taken) routes on the underground in 2020 (January 1st 2020 to December 31st 2020/or latest available data) measured by the greatest number of individual journeys with the same Entry, Pass-through, and Exit – as defined on page 24 of this TfL file: http://content.tfl.gov.uk/review-tfl-wifi-pilot.pdf

Please find the requested information in the attached spreadsheet.

SHEET 2: The 5 most complex routes recorded between the shortest physical distance in 2020 – i.e. the anonymised traveller who connected to the most Wi-Fi traps (Pass-throughs) between the closest (shortest distance possible in tube stops/as a bird flies depending on how TfL stores the data) Entry and Exit. This is discussed on the 2016 pilot.

If this is still too costly, for this second sheet could you send me the routes (Entry, Pass-through, and Exit) of the top 100 anonymised devices that connected to the most Wi-Fi traps on a singular journey (Entry to Exit) in 2020 (Jan to latest available data) instead.

Please note that in accordance with TfL’s obligations under data protection legislation (including the UK General Data Protection Regulation (GDPR) and Data Protection Act 2018) we are not able to disclose information on individual journeys, as it is exempt from disclosure under section 40(2) of the FOI Act. This is because disclosure of this personal data would be a breach of data protection legislation, specifically the first principle of the UK GDPR which requires all processing of personal data to be fair and lawful. TfL has satisfied the condition of section 40 (3A) of the FOI Act – it would not be fair to disclose this personal information when the individuals have no expectation it would be disclosed.

Any disclosure under the FOI Act has to be considered as a disclosure to the world at large. Due to the unique nature of these journeys there would be a very real risk that individuals could potentially be identified from the information, particularly if combined with other information that people may hold.

This exemption to the right of access to information is an absolute exemption and not subject to an assessment of whether the public interest favours use of the exemption.

For more information on this please refer to the ‘Sharing Information’ section of our WiFi Privacy page (https://tfl.gov.uk/corporate/privacy-and-cookies/wi-fi-data-collection) that states the following:

Individual depersonalised device Wi-Fi connection data is accessible only to a controlled group of TfL employees. Aggregated data developed by combining depersonalised data from many devices may be shared with other TfL departments and external bodies. Aggregated data will include counts of numbers of devices, rather than data containing pseudonymised MAC addresses.

If this is not the information you are looking for, or if you are unable to access it for some reason, please feel free to contact me.

If you are considering submitting a further FOI request please think carefully about whether the request is essential at this current time, as answering FOI requests will require the use of limited resources and the attention of staff who could be supporting other essential activity. Where requests are made, please note that our response time may be impacted by the current situation.

Please see the attached information sheet for details of your right to appeal.

Yours sincerely

Gemma Jacob
Senior FOI Case Officer
FOI Case Management Team
General Counsel
Transport for London

[email protected]

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