How To Trigger Green Traffic Lights

Ever found yourself or seen someone stuck for an unreasonably long time at a traffic signal, when there is no opposite or cross traffic?  Felt impatient waiting at such a signal, being a disciplined road user, adhering to traffic rules?  Well, do not worry, there is a wee bit of technology right at your foot, literally, involved in such times and some elementary knowledge into how these things work that can get you an instant green light every time you near such traffic intersections.

See, what happens in some remote and not so busy traffic junctions is that the police and city civic authorities have installed traffic lights but without an automated timer device to keep changing the lights at periodic intervals.  Such ones work well only where there is heavy traffic and thus will need to be regulated periodically.  So, coming back to the traffic signal lights in remote and non-busy junctions, these need to be triggered by some external mechanism for them to work.  So, how does one trigger the green traffic light?  It is so simple, really.  Here are some tips:

Common sense tells us that most automobiles are made of metal and most often comprised of ferrous metals like iron or steel.  So, some genius came up with this plan of lining the stop-line with a loop of metal that is connected to the traffic light system.  Now, consider an infrequently used road - vehicles come there occasionally, yet for safety reasons a traffic light is deemed necessary at that intersection.  So, what the authorities do is to place a sensor type of metal loop at the said intersection.  Every time the metal loop senses a large body of metal, it triggers the green light at this junction and turns on red at the perpendicular and opposite traffic points, thereby allowing your vehicle to pass. This change in status of signals sometimes takes up to thirty seconds.

How exactly does this work?  Let me explain:

1. A loop of metal is embedded into the asphalt very much near the stop line of a traffic light.  When you drive up in a car, it is most likely that you will go all the way up to the stop line in order to wait for the light to turn green.  When you do this, the metal loop embedded in the ground below your automobile senses the large mass of ferrous metal and triggers open the signal light so be sure you are stopped at the stop line and not prior to it.
2. What is the science behind it?  The loop is made of heavy inductive metal with a splice between the lead-in wire and the lead-in cable in a box.  When an automobile pulls into the loop, it generates a high degree of inductance which then closes the loop and triggers a reaction for the lights to change.
3. Now, does this work for all kinds of automobiles?  What if one were to approach such signals in a smaller vehicle, say a bicycle or motor-bike?  Yes, those may face problems and will have to wait until the signal does change per its long frequency. 

So in order to make the system work for a smaller automobile or two-wheeler, just attach a couple of strong pieces of neodymium magnets to the bottom part of the vehicle.  This emits strong signal and when near the metal loop, it triggers the light and off you go on your way.