The Department for Transport through the Bus Services Act 2017 requires requires bus operators and/or local transport authorities to openly publish information about bus routes and timetables, stopping places, fares and tickets, location information and more broadly the operation of bus services.
In July 2020 the statutory instrument to enable the DfT to mandate the provision of data was made:
https://www.legislation.gov.uk/uksi/2020/749/contents/made
RTIG have produced a quick guide to the dates and data formats required in the SI:
https://www.rtig.org.uk/system/files/documents/RTIGT040-2.0%20BODS%20SI%20Dates%20and%20Formats.pdf
The DfT have produced an implementation guide to support the statutory instrument:
https://www.gov.uk/government/publications/bus-open-data-implementation-guide
Routes and Timetables
These need to be published in TransXChange format.
The schema documentation for TransXChange can be found here:
http://naptan.dft.gov.uk/transxchange/
The Draft profile document is here:
The summary PowerPoint for the profile is here:
TransXChange: Public Transport Information Profile
Fares
Fares data is published in NeTEx format.
The details of this including profile documentation is available:
http://netex.uk/farexchange/downloads.htm
The schema is available on GITHub:
https://github.com/NeTEx-CEN/NeTEx
The formal NeTEx documentation is CEN copyright and available in the UK from BSI as PD CEN/TS 16614
Location Data
This will need to be published in SIRI VM format.
The details of this including profile documentation is being developed:
The SIRI schema is available on GITHub:
https://github.com/SIRI-CEN/SIRI
The formal SIRI documentation is CEN copyright and available in the UK from BSI as BS EN 15531