Talk:Dev:How To Reference Infrastructure

I am not convinced of the current usage of the terms "macroscopic" and "microscopic" in conjunction with "tracks identical to edges between nodes" and "tracks longer than edges between nodes".

In (not only) my language understanding, the terms "macroscopic" and "microscopic" suggest something like a zoom factor, a kind of detailed or rough. This has nothing to do with the length of tracks being longer or not longer than edges between nodes.

One could also imagine

• a rather detailed infrastructure model (with points, signals a. s. o.) with tracks longer than edges between nodes,
• a rather "rough" infrastructure model with relative short tracks which are not longer than the edges of that model (junctions, stations).

The typical relevant basic features are

• Detailed infrastructure model: Model includes points, signals, track elements. Nodes are points.
• "Rough" infrastructure model: Nodes are junctions/stations. Model does normally not "look into stations" in a wider sense.

In my opinion, we should write this into an introduction of the topic.

Now that we do not want to start again from the beginning, I could imagine the following:

a) Explicitly defining the terms "macroscopic" and "microscopic" describing the length of the tracks only. Defining new terms for "detailed" and "rough" independent from "macroscopic" and "microscopic". These new terms could be for instance "point-oriented" and "station-oriented". Then, one (we) should be aware that there may be also "macroscopic point-oriented" and "microscopic station-oriented" models.

b) On the other hand, we normally use the terms "long-track philosophy" and "short-track philosophy" in all-day life instead of "macroscopic" and "microscopic". So, possibly we should use that therms in future for the length of the tracks and leave the "macroscopic" and "microscopic" as synonyms for "detailed, point-oriented" and "rough, station-oriented".

I would prefer the latter one (b).

--Dirk Bräuer 16:12, 10. Nov. 2012 (CET)

Under Construction

As discussed in the TT developer group, the Guide does not help in understanding how to reference infrastructure. Complete overhaul was deemed necessary.
RailML Coord Documentation (talk) 12:35, 13 March 2023 (CET)

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This article explains basic concepts of how to describe infrastructure and how to reference it from the timetable subschema

Dieser Artikel erklärt die Grundkonzepte für das Beschreiben von Infrastruktur und wie man auf diese auf dem Fahrplan-Subschema verweisen kann.

How to describe infrastructure / Beschreibung von Infrastruktur

In general we distinguish between the macroscopic and the microscopic approach of describing infrastructure. These are two ways of looking at the same set of tracks and stations a railway is made of. The microscopic approach is focussed on a very detailed description. In a microscopic infrastructure description in railML^® tracks usually are limited by switches, crossings, bufferstops and such. In railML^® that would meant that usually a <track>s <trackTopology> defines its <trackBegin> and <trackEnd> as either <connection> (<connection>), <bufferStop> or <openEnd>.

Different usages of the infrastructure schema

The macroscopic infrastructure model considers tracks as a connection between ocps. This model is typical for a timetable view.

The microscopic infrastructure model considers tracks as a connection between switches. This model is the preferred one for a simulation tool or a signal box view of the infrastructure.

To create unique references from a train part to the infrastructure with these two models, it is assumed that

• in the macroscopic model in railML there are 'long' tracks, i. e. the tracks cross several switches, junctions, or OCPs.
• in the microscopic model in railML there are 'short' tracks, i. e. the tracks are only defined between two switches or junctions but usually do not cross switches or junctions.

Das makroskopische Infrastrukturmodell betrachtet Gleise als eine Verbindung zwischen Ocps. Dieses Modell ist typisch für eine Fahrplansicht.

Das mikroskopische Infrastrukturmodell betrachtet Gleise als eine Verbindung zwischen Weichen. Dieses Modell ist das bevorzugte Modell für ein Simulationswerkzeug oder eine Stellwerkssicht der Infrastruktur.

Um mit diesen beiden Modellen eindeutige Referenzen von einem Zugteil zur Infrastruktur herzustellen, wird angenommen, dass es

• im makroskopischen Modell in railML 'lange' Gleise gibt, d. h. die Gleise queren mehrere Weichen, Kreuzungen oder OCPs.
• Im mikroskopischen Modell in railML 'kurze' Gleise gibt, d.h. die Gleise sind nur zwischen zwei Weichen oder Kreuzungen definiert, und queren normalerweise keine Weichen oder Kreuzungen.

How to define it with railML?

Example 1

If the infrastructure is used in the macroscopic way, only one <trackRef> element should be used for an <ocpTT>.

Example 2

If the infrastructure is used in the microscopic way, you will have to list all tracks (from switch to switch) as <trackRef> elements until you reach a track which contains a <crossSection> element related to the next <ocpTT>.

To list more than one track at <trackRef> shall only be done if the tracks are 'short', i. e. if they are defined between two switches or junctions only but not longer. This secures the description of a train part's route to be unique.