Second IDX4rail Expert Workshop Day in Cologne: Insights to the Alpha Model

On June 04^th, 2025, the IDX4rail consortium met with experts on infrastructure data of several rail- and tramway operators at a hybrid conference held by the Association of German Transport Companies VDV (“Verband Deutscher Verkehrsunternehmen”) in Cologne. Highlights of the conference were the presentation of the IDX4rail 1.0 (equates to railML 3.4) Alpha 2 data model and an update on the project roadmap.

IDX4rail is a railML partner project which aims to consolidate data for railway and tramway infrastructure by harmonising the industry standards railML^® and IDM^VU, a German standard for infrastructure data management for tramway and light rail. Like railML, IDX4rail modelling is use case based, ensuring seamless implementation in practice. During requirement analysis, eight specific use cases were identified, which are now being modelled incrementally. The order in which the use cases are modelled follows the logical hierarchy determined by their interrelation. Following this reasoning, four out of the eight use cases were initially prioritized, namely railTopoModel, General Data, Track Geometry and Asset Status Representation. Their modelling was showcased for insight into version Alpha 2 at the conference.

Due to unanticipated additional workload, the harmonisation analysis could only be concluded by December 2024, which consequently delayed the preparations for the modelling phase. However, until summer 2026, the delay in the overall project schedule will ultimately be limited to six months by switching from the originally intended waterfall model to an agile approach.

Since June 2025, the first Beta version of IDX4rail 1.0 (equates to railML 3.4) has been available to rail- and tramway operators and software manufacturers. In this version, all eight use cases (railTOPOMODEL, General Data, Track Geometry, Asset Status Representation, Schematic Track Plan, Inspection and Maintenance Data, Network Statement, Topology Update) are at least basically modelled. As a next step, initial import and export tests will be conducted and feedback from the tramway operators gathered through workshops. These results will be used to refine the model. Model version Beta 2 will be presented at the 48^th annual railML Conference on November 5^th, 2025. Community feedback is eagerly awaited. A few days later, on November 12^th, 2025, outcomes of Beta version testing will take the spotlight at the Third IDX4rail expert workshop day hosted by the Leipzig transport company LVB (“Leipziger Verkehrsbetriebe”).

The IDX4rail 1.0 (equates to railML 3.4) data model and accompanying documentation are expected to be completed in spring 2026 and will be made available as open source and open access to all rail- and tramway operators, software manufacturers and other users in summer 2026. Simultaneously, a draft for an update to VDV document 456 will be submitted to the associated committee.

The final product is set to be demonstrated at the InnoTrans fair 2026.

As mentioned, a Beta version for IDX4rail 1.0, respectively railML 3.4 has been released since June and is available for download on the railML schema download page. If you are interested in joining the review process for Beta 1, please reach out to orga@governance.railml.org. Your input is greatly appreciated.

Also, if you or one of your colleagues wishes to attend the next IXD4rail expert workshop on November 12^th, 2025, in Leipzig, Germany, it is possible to do so both in person and virtually. More information on the agenda, the location and possibilities to sign-up are available at the Third IDX4rail Expert Workshop Day webpage. The event will be held in German language.

The project IDX4rail is funded by the German Federal Ministry of Transport as part of the mFUND initiative with a sum of 1 549 Mio. Euro.