You are looking at a track message concept

Messages along the ram track (grape vine?)

someone requests the tram by triggering the track near them. This sets itself as the destination then finds all exits with a track in them and changes their state in some way.

Tracks with a changed spate then search for exists with tracks in them, and do the same.

This raises the question of a new field:
- objects having a switch variable - they dont process code if switched off.
switch $tactor off