Presentation of Additions and Changes in IDX4rail Beta 3 and State of Documentation

On April 16th, 2026, the IDX4rail project consortium met with experts in the field of infrastructure data including various railway, tramway, and light rail operators and software developers. The 4th IDX4rail Expert Workshop Day took place in hybrid format and was hosted by the Munich City Utilities (Stadtwerke München GmbH, SWM).

The event focused on the strategic context of the IDX4rail data exchange format, changes and newly modeled additions to use cases in the Beta 3 (based on community feedback to Beta 2), a converter demo IDMVU to IDX4rail , as well as the roadmap to release of IDX4rail 1.0 and an updated VDV Recommendation 456. Furthermore, the event featured exciting guest lectures by the host SWM and other industry partners.

IDX4rail explained

IDX4rail is a railML® partner project which aims to consolidate data for railway, light rail, and tramway infrastructure by harmonizing the industry standards railML and IDMVU, a German standard for infrastructure data management for tramway and light rail. Like railML, IDX4rail modeling is use case based ensuring a seamless implementation into practice based on actual data exchange needs.

Modelling of IDX4rail Beta 3 – Changes and New Additions to Use Cases

Since the IDX4rail Beta 2 version was presented at the 3rd Expert Workshop Day in Leipzig, community feedback was carefully taken into consideration. Thanks to the feedback the Beta 3 features some changes and new additions primarily in the use cases track geometry, survey data, and maintenance data.

Community feedback inspired adding the topic of superelevation in the geometry part of the model. The feedback also led to changes that significantly extended the model details in the topic areas level crossing, switch and crossing, and track bed.

For the use case survey data new additions were added in the Beta 3 to include survey meta data, references (time, location, external data), and survey findings among other changes allowing the linking with measurement data stored in various different (binary or table-based) formats.

For the use case maintenance data new additions feature data about maintenance operations such as location designators, timely validity of the operation (e.g. one-time, recurring, or seasonal) and other referencing options. Changes to the topic area designators grant users more freedom to reference unique and specific requirements (e.g. project guidelines) as well.

The IDX4rail Beta 3 model is based on RailTopoModel and includes (apart from the already implemented use cases) the railML use cases Track Geometry and Alignment, Infrastructure Asset Status Representation, Maintenance Planning for Infrastructure and Network Statement.

Topics of Consortium and Partner Lectures

Milan Hoffmann, railML.org, kicked of the 4th Expert Workshop Day by laying out the strategic context of IDX4rail. Hoffmann recapped the initial situation with a significant overlap in the infrastructure domain between railML and IDMVU paving the way for the IDX4rail project. It was also highlighted that IDX4rail is based on the RailTopoModel and is intended to employ the same infrastructure model as railML 3.4 to ensure the same base for light rail and heavy rail. Furthermore, the use case approach as well as the IDX4rail 1.0 use cases were summarized. In closing, Hoffman provided a look at potential connections to other standards, railML domains and use cases extending the potential of IDX4rail to the heavy rail sector.

Christian Rahmig, DLR, introduced the current state of the IDX4rail modeling (Beta 3) and the newest changes on technical level inspired by community feedback on the Beta 2. As mentioned before, the focus of these changes were the use cases track geometry, survey data, and maintenance data.

Giuliano Scollo, DLR, demonstrated the IDX4rail converter showcasing the transformation of an IDMVU example file into IDX4rail format with two approaches. The first approach featured a JAVA-Script solution ideal for local use on individual computers. The second approach featured an API solution with Quarkus intended for permanently accessible web applications and organization wide use. The IDX4rail files produced by the converter can be validated for readability with the railVIVID tool.

Vasco Paul Kolmorgen, railML.org, and Andreas Beck, VDV, outlined the road to an updated VDV Recommendation 456 IDX4rail. Kolmorgen began with an overview of the current state of the documentation (which will become the new VDV Recommendation), how each chapter is structured, and how the documentation is intended to be used after publishing. An updated timeline for the IDX4rail 1.0 release in November 2026 was provided as well. Beck then moved on to the VDV publishing procedure. He highlighted the critical milestones the proposal for the updated VDV Recommendation has to pass and specifically emphasized the critical role of the tram and light rail community in the 8-week survey phase. Beck urges the community and sector to start nominating relevant members of their organizations to join the task force today to streamline the survey procedure later in November.

Professionals are strongly encouraged to join the VDV 456 survey task force.

Please contact us at info@idx4rail.railml.org to get involved.

In the afternoon, Bernd Kaiser, GüteZert, hosted a discussion on the needs for training and certification services in the IDX4rail community. The discussion once again underscored the importance of coordinated community efforts to advance standardization. This is particularly critical for supporting the adoption of IDX4rail after its launch, given the railway and light rail sector’s heterogeneous software landscape, which makes the delivery of targeted training inherently difficult.

In closing, Kolmorgen assured the community that the IDX4rail standard would continue to be maintained and developed even after the official conclusion of the project. He pointed to the IDX4rail-Website for the roadmap to release and for access to the Beta 3 for testing in the community.

For IDX4rail to become the future-proof standard it aspires to be, your feedback is essential. Only through an engaged and participatory community - providing input on our modeling and proposing new use cases - we can ensure the standard’s quality and relevance in the long run.

We invite you to review Beta 3 and share your feedback by June 17th, 2026, via info@idx4rail.railml.org.

Guest Lectures from Industry Partners

1. Dr.-Ing. Philipp Striegl & Alexander Glatz, SWM, speaking on the digitization of the Munich subway infrastructure using 3D laser scans in an mobile mapping approach.

2. Michael Liebig, DVB, speaking on introducing an infrastructure data management system in a large public transportation organization in Dresden.

3. Mario Rainer, RSV, speaking on Asset Management with MR.pro for tram, light, and heavy rail as well as outlining challenges software developers face in the railway sector.

4. Jakob Geischberger, DLR, speaking on railway operations simulations using the open-source tool SUMO for intermodal urban transportation planning.

All provided slides of consortium and guest lectures are available on the IDX4rail-Website.

IDX4rail Roadmap 2026

On June 17th, 2026, version Beta 4 will be provided for community feedback. By September 2026, modeling of all relevant use cases will be completed and an IDX4rail 1.0 Release Candidate will be published for a final round of feedback. The use case “Topology Update” will not be implemented as part of IDX4rail 1.0, as it is only relevant for a follow-up project to update the standard.

IDX4rail 1.0 will be officially released on November 5th, 2026, alongside a tool for converting data records from IDMVU to IDX4rail. For the validation of IDX4rail files, the railML validator software railVIVID will be configured accordingly, reflecting the close proximity of the IDX4rail data model to railML 3.4.

At the same time, the VDV will submit the survey procedure for updating VDV Recommendation 456 to the relevant committee. This will amplify IDX4rail’s significance withing the industry appropriately. Preparations for this have already begun. The updated VDV Recommendation 456 is expected to be published in spring 2027.

Upcoming Events

49th railML Conference (virtual) on June 17th, 2026, inviting all railML partners to join the review process of the latest Beta 3 version for IDX4rail 1.0 - respectively railML 3.4 - released on April 16th, 2026 and available for download. Share your feedback at the conference or via info@idx4rail.railml.org. Your feedback is greatly appreciated!

InnoTrans 2026 from September 22nd to 25th, 2026 in Berlin, featuring a closer view at the IDX4rail Release Candidate and further information at the booths of consortium partners.

5th IDX4rail Expert Workshop Day on November 10th or 11th, 2026 in Berlin, marking the completion of the project. railML.org is open to continue with maintenance of the project IDX4rail after its conclusion, if there is demand from the community to do so.