How does traffic light sensors work

How does traffic light sensors work? This must be a question that has been ignored by people who drive to work everyday, because it is too familiar to trigger your curiosity. Nowadays in those massive cities, traffic lights are controlling the public transportation in a effective way. We cannot imagine a day without the traffic lights, however, we barely ask the question of how does traffic light sensors work.

How does a traffic light sensors work so that you’ve pulled up to a red light, and know to change it in a few seconds so you’re not waiting there all day? It depends on a few factors such as where you live and how much traffic travels through that intersection.

There are all sorts of technologies for detecting when a car has approached the intersection -- everything from lasers to rubber hoses filled with air. By far the most common technique is the inductive loop, which is the key to help we understand how does traffic light sensors work.

What’s an inductive loop?  An inductive loop is simply a coil of wire embedded in the road's surface.  A traffic light sensor uses the loop in that same way. It constantly tests the inductance of the loop in the road, and when the inductance rises, it knows there is a car waiting! I believe all these information can help you find the answer to the question how does traffic light sensors work.

Isn’t it interesting to think about a question so familiar such as how does traffic light sensors work? We choose to neglect those things that are so important and common in our daily life. However, when we find the theory and knowledge behind those familiar existence, we actually review our life in a different prospect.