The latest version of railML® - railML® 3.3 was made public on 5^th November, 2024. It introduces several new features within the railML subschemas, namely Infrastructure (IS), Rolling stock (RS) and Timetable (TT). It also incorporates significant modifications from railML 3.2, with the objective of enhancing data interoperability, accuracy and ease of use.

New Use cases

• Run Time Calculation Import (RTCI): railML 3.3 was extended in the Infrastructure (IS), Rolling stock (RS) and Timetable (TT) subschemas to support the functionality run time calculation import. It allowed the specification of data required as input of run time calculation programmes.
• Long-Term Circulation Planning (LTCP): This use case within the timetable subschema enables the definition of vehicle circulations prior to the completion of the timetable, thus facilitating the more effective management of resources during the initial stages of planning.
• Possession Management Analysis (POMA): The timetable subschema introduces features of possession management that allow users to encode restrictions and possessions directly. This will make track closure management and other operational constraints easier in the context of timetable planning.

Key updates from railML 3.2 to railML 3.3

• Additions on ETCS level 1: In railML 3.3, support has been extended to include ETCS track net level 1, in addition to the existing support for ETCS track net level 2.
• Specification of Signals: The subschemas for Infrastructure and Interlocking have been updated to simplify the specification of complex signal situations.
• State Management: In version railML 3.3, state information for Infrastructure, Interlocking and Rolling stock elements will have one common way of encoding as well as deviations from these. This new encoding not only replaces the existing state description in the IS subschema but also provides enhanced support for the handling of deviations and for the consistency of elements.

Subschema-Specific Updates

• Infrastructure: In railML 3.3, we streamlined the methods for describing the location of infrastructure elements, significantly reducing redundancy and improving consistency. This approach to positioning simplifies the process for software manufacturers to import data and provides a more intuitive framework for users.
• Infrastructure: In order to support splitting and joining infrastructure networks, netConnectors were introduced. A network can thus be temporarily 'detached' from and later reattached without the loss of information that would otherwise be critical to the implementation of flexible infrastructure management.
• Timetable: The use cases – LTCP and POMA were introduced.
• Common: In railML 3.3, the concept of metadata specification was revised by employing the latest iteration of the Dublin Core metadata standard and included the Dublin Core Terms. This update facilitates compatibility with contemporary metadata standards and provides more comprehensive and adaptable descriptions for railML data elements.

In conclusion, the version of railML 3.3 marks a significant advance in the standardisation of railway data. It meets the demands of users, increases the format usability and aligns with the evolving requirements of global rail systems, reflecting the commitment of railML to meet the needs of the industry. For railway organisations and software developers, railML 3.3 provides a robust foundation on which to address today's challenges and prepare for tomorrow's innovations.

For further technical details, please refer to the railML® 3.3 documentation and schema, available at railML.org. railML 3.4 deveopment will begin in January 2025 and we welcome proposals and suggestions for new use cases.

The 47th railML conference is scheduled to take place virtually on 17^th June, 2025. Registration will open for all members of the railML community in February 2025. We look forward to welcoming you at the next conference!