Stoplights that don't turn

[LightningGSX]

At some intersections I have seen more than one sensor(one for the 3M Opticom, and one for something else).I know stoplights use different control strategies for light and heavy traffic times, usually timed for heavy traffic times(day), and a pressure or proximity sensor for light traffic times(night).It is entirely possible the other sensor I have noticed is there to spot headlights at night, so the stop light "knows" traffic is waiting to cross.In fact, using a sensor to "see" headlights at night makes a shitload of sense(to me at least).Also, there are many different versions of the Opticom(not Opticon), and even custom made to order.So its possible there is a version that will look for visible light as well(for control purposes).When retrofitting a stoplight, it would cost alot less that way, than it would digging up the pavement to implant a pressure or proximity sensor.I've always heard the headlight thing was a myth though, who knows.

[Khadgar]

Well on the one lately my headlight is out on the left side, maybe that is the cause? Otherwise i have only had the problem a few months ago