How do traffic lights work?

(2011-04-02 14:25:19) 1. epicninja Says: Do they run on a timed system, or are their sensors of some kind?2. John R Says: It's a miracle. Like rainbows.3. Siete Dos Aletas Says: Sensors....

Next time you're approaching a stop light take a look at the ground ahead of you. (don't run into anyone though). You will see huge squares or circles cut in the ground. Actually, you would see the outline of huge holes that were dug and sensors places in them. Might be better to walk up to a cross section and take a look. I believe you will see them more clearly that way.

You ever see those folks sitting at a light for a long time and start to move their car forward and backward several times? They are trying to trip the sensor.4. Zac Says: Pressure plates under road...
look like big circles.... Tag: How do traffic lights work?