We go with the theory people are stupid and when they see red lights try to prove it.

A few years ago at 3 AM we were on a truck with ALL the lights running, parked northbound in the southbound lane at an intersection with 2 firefighters in front of it in turnout gear with reflective stripes, carrying flashlights, one holding a stop sign on a pole. And STILL we had stupid people try and go around it!