My name is Georg Boasson and I am working at Bane NOR in Norway with implementing the ETCS signal system.

Bane NOR need to indicate the working process when doing a redesign of our signal systems. This is very valuable information in the migration phase, especially when replacing conventional signals with ETCS signals. So far, we have used an attribute in the Norwegian extension of railML2.4 to indicate "new", "removed" and "modified" elements.

My suggestion for implementation of this feature in railML3.1 will be to use the element <infrastructureState> with the sub-element <elementState> and the attributes @refersToElement and @value.

The elementState@refersToElement attribute will be used to reference any element in the infrastructure model (ex: <SignalIS@id>).

The elementState@value attribute will be used to indicate the state of the referenced element:

Removed @value="disabled" or "closed"
New --> @value="operational"
Modified --> @value="conceptual"
Unchanged --> no @value defined

Is this an acceptable way of implementation? Or anybody have other suggestions?