Request ID: FOI-4450-2324 Date published: 11 April 2024
You asked
I am undertaking a research project investigating the affect of different variables on a modal shift from private to public transport following the implementation of a Low Emission Zone. I am looking to use Logistic Regression Analysis with variables such as those in the LTDS. For Logistic regression however, I need a string of results for each agent/individual as opposed to aggregated results for categories. This is typically obtained by means of a survey. As a result, is it possible to have access to the questionnaire results that informed the LTDS? Obviously private information such as names etc. are not necessary I would just need to be able to assign variables such as age, income, household type, location of home/work, transport mode to work all for the same individual.
Thanks in advance
Clarification received 12/03/2024: If possible, I would like the survey & results for the most recent survey (which I believe is 2022/23) and ideally the 2019/20 edition as well.
Again, I would like to clarify that no personal information is required (names, addresses etc.). I just need the data in questionnaire format so I can assign all responses to an individual “agent” instead of taking the average / aggregate results, hence why the LTDS report on TfL’s website is not sufficient.
We answered
TfL Ref: FOI-4450-2324
Thank you for your request received by Transport for London (TfL) on 29th February 2024 asking for information about the London Travel Demand Survey (LTDS).
Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.
Specifically you asked:
“Is it possible to have access to the questionnaire results that informed the LTDS? Obviously private information such as names etc. are not necessary I would just need to be able to assign variables such as age, income, household type, location of home/work, transport mode to work all for the same individual.”
On 12th March 2024 you clarified that you would like to see the results of the 2019/20 and 2022/23 surveys.
I can confirm that we hold the information you require.
Given the size of the relevant files, rather than send them by email we are providing them to you by providing access to a Sharepoint file on which they are stored. You should have received an email separately that provides a link to that site. If you have not received such a link (and please check your junk mail folder first) please let me know and I will ensure it is sent again.
Please note that given the nature of the information held it is not possible to provide you with all of the information in the exact form held by TfL. This is because the combination of information held would allow individuals to be identified, in breach of our obligations for the fair processing of third party data under the General Data Protection Regulation (GDPR). We have, therefore, combined or anonymised some of the information held. For example, rather than provide the ethnic status of the respondents according to one of the 17 original categories, these have been grouped into four categories to reduce the specificity of that information. Similarly, rather than provide the exact start and end point of journeys we have reduced this to the borough-level only. Such changes have been made under section 40(2) of the Freedom of Information Act, the exemption which protects against the unfair release of personal data (and which, in effect, ensures compliance with GDPR obligations when responding to FOI requests).
I understand that this may mean that the data provided does not meet your exact needs. However, it is, in our judgment, the correct balance for releasing information under FOI law – that is, providing as much of the requested information as we can while at the same time protecting the identity of third parties. If this does not meet your needs it may be possible that a more detailed version of the data might be available via another route. This would involve your University entering into a data sharing agreement by signing our standard, non-negotiable Academic Confidentiality Agreement (ACA). This is a matter you would first need to discuss with your University and requires a member of faculty to act as Principal Investigator and the ACA would need to be signed by authorised signatories at TfL and the University. The process would also involve a Cyber Security audit and approval of the University’s secure technical solution for storing, handling and analysing identifiable data and a Privacy by Design and Default evaluation. If your University does want to explore such a route, then TfL can be contacted for such requests at: [email protected]
Finally, please note that the following will help you to understand / interpret the data:
Variable definitions are shown by opening a table, right click on the heading and select 'design view'.
Variable categories can be added by joining the relevant label table.
The household, person and trip tables follow in a hierarchy and can be linked to look at variables across the tables in this hierarchy. For example linking the 'hhid' variable in the household table to the 'phid' variable in the person table.
A few variables have been categorised in order to ensure we comply with GDPR requirements for personal data. These include:
pegroup1 - ethnic group
page - age
pwkstat - work status
tdbmmode - trip based main mode
topurpi - origin purpose
tdpurpi - destination purpose
tjpurpi - journey purpose
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely,
David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
