Traffic Lights and Motorcycles

By: On: August 22nd, 20090 Comments »Updated: January 9, 2012

motorcycle at traffic light with wheel on signal sensorFor a motorcyclist, one of the more frustrating circumstances to be stuck in is to be trapped at a red light that never changes.  This can happen at intersections that use what are referred to as loop detectors in the pavement.

A loop detector is supposed to sense if a vehicle is present or not and they trigger the traffic light to change.

As we explain below, motorcycles often are not sensed by these loop detectors, but the position where you stop at a light can actually solve this problem.

If you are like me, you usually stop near the center of the loop.  At the motorcycle safety course, they didn’t explain how to get traffic lights to change.  I’m an engineer, and I have to admit that I never gave it much thought as to how these things actually work.  I assumed wrongly that if I was in the center of the loop that would give me a better chance to trigger the light.  In fact, the best place to have your motorcycle is directly on the loop, not in the center area.

A loop detector is a loop of wires that sense if there is something metallic near them.  If you are stopped in the center of the loop, your motorcycle is usually not close enough to the wires to be sensed.  By stopping directly on top of the wires, right on the lines on the pavement, then you will have the best chance to be detected.

motorcycle at traffic light not on signal sensorThere are two main types of loop detectors used at traffic signals.  One is a large rectangle shape, and the other is a rectangle with a line down the center of it.  If you are into trivia, the first type is called a dipole loop and the second type is called a quadrapole loop.  If you are at a dipole loop, then stop on top of either line that is parallel to the road.  If you are at a quadrapole loop, then you should stop on top of the center line.

There are motorcycle accessories on the market that are supposed to make your bike easier for these loop sensors to detect.  Some of those use a strong magnet that you mount underneath your motorcycle frame.  The theory with the magnet is that the magnetic signal will be detected easier by the loop detector than the motorcycle would have been by itself.  I have never tried one of these accessories, so I don’t know if they are actually worth the money.  I personally don’t feel that it is a very wise idea to mount a powerful magnet, on your motorcycle since you don’t know if that will damage or interfere with your motorcycle’s critical electronic systems such as the fuel injection, ignition and more.

With that in mind, I feel the best motorcycle information for getting a traffic light is to change is stop directly on and in line with the loop, especially if is the type that has the line down the center of it that you can stop on.

About John Clay

John Clay is the author of MotorcycleInfo.Org. He and his family reside in North Carolina in the United States. A graduate of the Motorcycle Safety Foundation's Experienced Rider Course, he enjoys riding his Moto Guzzi in charity rides and serves as a volunteer motorcycle marshal for an annual bicycle charity event in the Carolinas.

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