side and position device attributes;
chainage_m derives the position if that is not set. Cells
with a dashed outline are placed by guesswork because
neither was provisioned, so their position is not authoritative.
Select a passage to see its per-second shape. Passages captured before the node had the trace enabled, or uploaded after the node had already dropped them from memory, show no trace β that is reported rather than drawn as an empty one.