A graphic tool and a style sheet that shows track distance in accordance with the definition from EN-15273-3, chapter 3.2 are desirable.

The point is that the distance between two tracks, measured from track center to track center, shall be measured perpendicular to the track with the least cant and projected perpendicular into the ToR-plane (the plane that touches the surface of both rail heads).

I imagine that the graphical tool should work in a similar way as the “Tracking” function in Bentley/Power Rail Track. This function has the property that, after snapping to a neighboring track, you can follow the horizontal distance continuously.

If one or both longitudinal profiles have not been prepared, the distance will not be completely correct. In such cases, I suggest that the tool can assume the same elevation in the two tracks.