Oblivious to Modern Technology (once again)

I was sitting at a red light the other day and happened to look up and notice that the traffic light for the cars crossing my lane was really thin. Like razor-thin. Like if-you-took-off-the-glare-shields-and-the-light-turned-sideways-you-could-barely-see-it thin. When did this happen?

Sure, I had heard the rumors about LCD lights being used in traffic lights. I had even noticed that some traffic lights appear to have flat lenses now instead of the rounded lenses I was used to. Yet in my mind, the depth of traffic lights remained the same, regardless of the type of light used. I was picturing all lights to be as thick or thicker than the light in the photo above, only to find that I am completely oblivious to modern technology once again!

On a related topic, for years I have been curious about how lights know when to change colors. Sure, some lights are obviously just on a basic timer, but what about those lights that seem to know when a car is waiting on a low-traffic road and can change in response? If you are curious like me, you need to wonder no more, because I have finally gotten around to doing the research for you! You will be happy to know that some lights have a metal-detector-type sensor buried under the pavement that can detect the metal in your car and know that someone is waiting. Of course, if you drive an all plastic car, this will be an issue. Otherwise, it works nearly flawlessly.

Next time you're sitting at a light, look up. Are you shocked by its thinness also?