Rename 'dir' attribute in 'mileageChange'

Description

The <mileageChange> element provides a dir attribute which refers to the absolute mileage (absPos) along the line/track.

In contradiction to that, the dir attribute is used for the relative positioning direction (pos) in other railML infrastructure elements.

For better understanding, rename the dir attribute in <mileageChange> element to absDir.

Links

• Forum discussion
• Susanne Wunsch, 13.04.2012: [https://www.railml.org/forum/index.php?t=msg&th=124&goto=299&#msg_299]
• Trac ticket
• Wiki documentation

Proposed solution railML 3.1

In railML 3.1 mileage changes are modelled using elements of . An example for a linear positioning system (mileage system) with a gap at kilometre 1.000 and an overlap at kilometre 2.000 may look like this:

<linearPositioningSystem id="lps01" units="m" startMeasure="0.0" endMeasure="5000.0" linearReferencingMethod="absolute">
   ...
   <anchor id="lps01_anc01" measure="1000.0" measureToNext="0.0"/>
   <anchor id="lps01_anc02" measure="1025.0" measureToNext="975.0"/>
   <anchor id="lps01_anc03" measure="2000.0" measureToNext="0.0"/>
   <anchor id="lps01_anc04" measure="1950.0" measureToNext="3050.0"/>
</linearPositioningSystem>

The direction of the mileage does not change within one linear positioning system. So, if you want to model a change from increasing to decreasing mileage, you need to define another with a @startMeasure being greater than the @endMeasure. Consequently, there is no @dir attribute for mileage changes.