Re: Lawful?
Without wanting to detract from your main point,
Deliberately tampering with infrastructure such as traffic lights should be avoided, but failing this then if targeting shared infrastructure then they should be disabled totally, and not set them up to occasionally all show green, etc.
Forcing traffic lights to all-green is actually just an annoyance; it's not dangerous, despite what you see in the movies. Each signal controller is fitted with a separate watchdog unit which will detect such conflicts. The watchdog is a simple device which cannot be defeated by configuration - it's basically a wired-OR function. And when it trips, it takes out the fuse to the signal group, causing all the signal heads to turn off.
Having junctions that are normally signal-controlled suddenly becoming uncontrolled isn't great for traffic management, but that's a whole lot safer than having conflicting greens...
Vic.
Biting the hand that feeds IT
