[Michael Beard]

There is a "Staged Minimum" setting in Autostart (typically 0.6-0.7) that prevents Autostart from being activated by just a bare flicker. If there are two pre-stage bulbs lit and one of the Stage bulbs is lit for more than the Stage Minimum time, then Autostart is active (and it does not reset if a car backs out).

Both instances were legitimate timeout redlights.