i see these on tons of traffic lights and never knew what they are? they can't be red light cameras cause they are everywhere and they don't have that many red light cameras:
http://www.its.umn.edu/Publications/...oute-light.jpg

 

I think thats the car sensor. not sure on the technical term, but it tells that there are cars at the light, and aides in the computer deciding when to change the lights colors.





I think.

 

That has always been my guess.

 

they must do something like that, cause they have one of the little "radar" things with them that is white and points down at the line so they must go hand in hand ive just always been curious to know what they are exactly

 

It's the receiver for a MIRT. A MIRT is on top of all emergency vehicles and when they need the light turned green they flash their MIRT and that receiver turns the light green.

 

^and theres the answer

 

damnit. that was always my 2nd guess.

 

ah chit. I forgot all about those things... Read online somewhere how to make one too...

 

http://www.i-hacked.com/index.php?op...sk=view&id=176

 

thats the site. lol