Odd Lights on Traffic Signal Poles

fta12
1:06p, 8/21/11
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AG
Anyone else notice the regular looking light bulbs oriented sideways on the poles of traffic signals around town? I have never seen them before in a city and am curious as to what they are for. I will try and post a picture later this evening if no one can figure out what I'm talking about.
classicdoug
1:15p, 8/21/11
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AG
They are so a policeman can sit anywhere around the intersection and catch red light runners. I don't remember which way they work, but they each correspond to a red light and turn on or off when that light turns red.
AgResearch
1:16p, 8/21/11
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AG
They turn on in your direction when cross traffic's light turns red.
fta12
1:19p, 8/21/11
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AG
Thanks all. I couldn't come up with a good explanation for them.
CS78
1:46p, 8/21/11
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They are to let you know when to hit the gas while your light is still red but about to change. Kinda like the light tower on a drag strip.
techno-ag
2:40p, 8/21/11
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Doug is correct. They assist LEOs so they can monitor red light runners from different angles at an intersection.
bcsrunner
10:18p, 8/21/11
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All correct. We call them "enforcement lights," but I have also heard "tattletale lights," and even "rat lights" (as the original version was a gray-colored box and the wires made it look like a rat. If there are two lights on one pole (one on top of the other), the top one is for the left turn phase, and the bottom for the thru phase. Drive safely!

Dale Picha
Bryan, Texas
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