The Topology Layer: Modelling How Your Network Connects
The most significant new requirement is the micro-level topology layer. This builds on the connectivity model that RINF already had—and extends it significantly.
What RINF Already Had: Macro-Level Connectivity
The original RINF wasn’t without topology. Sections of Line (SoL) explicitly connected Operational Points through SOLOPStart and SOLOPEnd parameters. A route across the network could be traced as a chain: OP → SoL → OP → SoL → OP.
This macro-level connectivity was sufficient for the original Route Compatibility Check. RCC could traverse from station to station, checking infrastructure parameters along each Section of Line. The question “can vehicle X travel from Brussels to Amsterdam?” could be answered by checking the SoL chain between those operational points.
What’s New: Micro-Level Topology Inside Operational Points
The 2026 requirements add a new layer: explicit modelling of how tracks connect inside operational points.
In a complex station, a train doesn’t just “arrive” and “depart”—it follows a specific path through platforms, switches, and crossings. Different paths through the same station may have different characteristics. The new topology layer captures this internal structure using NetElement and NetRelation classes.
This enables more precise Route Compatibility Checks. Instead of just knowing that a vehicle can travel to a station, RCC can determine which internal routes through that station are compatible—which platforms, which connections, which paths.
What You’ll Need to Provide
Abstraction layer (how things connect)
- NetElement — nodes in the network graph (representing track segments)
- NetRelation — connections between elements, with navigability properties
- NodePort — connection points on each element
Implementation layer (what exists)
- OperationalPoint — stations, junctions, border points
- SectionOfLine — line segments between operational points (as before)
- Track — running tracks and sidings
Crucially, both layers must be present and consistent with each other.
Practical Considerations
For many organisations, internal station topology has never been formally documented in structured data. The macro-level model—which stations connect to which lines—was well understood. But the micro-level detail—how tracks connect through switches and crossings inside a station—often exists only in signalling plans and operational experience.
Capturing this systematically requires coordination across departments: signalling, operations, and asset management all hold relevant knowledge.
Warning: ERA’s validation will flag disconnected elements and “sinking points” (elements with no outgoing connections). Your network must form a coherent, traversable graph at both macro and micro levels.