Inductive Loop Detectors and Motorcycles
by FastFred
Many motorcyclists are often frustrated by traffic
light sensors that fail to detect their motorcycles. The inductive
loops is a vehicle sensor that is simply a coil of wire embedded
in the road surface. An electronic module in the traffic signal
control cabinet sends a signal through the loop. When a mass
of ferrous metal passes over the loop a shift in the electrical
signal will occur. If the shift detected is great enough, the
module tells the computer that a vehicle is present. The key
point is the mass of metal must be great enough to overcome
a threshold. Only ferrous metal objects above the threshold
are detected.
Many motorcyclists have resorted to purchasing
a variety of products designed to help increase detection by inductive
loop traffic sensors. I have personally tested these devices
on my motorcycles and was greatly disappointed by lack luster
performance. Save your money because these devices do not work.
Traffic lights in cities in high traffic areas
often operate on timers instead of detectors. However detectors
are common in the suburbs and on country roads. They may detect
when a car arrives at an intersection to trigger a light change
or when too many cars are waiting at an intersection to control
the length of the light. Detectors are often used to detect
when cars have entered a turn lane in order to activate the
arrow light.
If you are interested in learning more inductive
loops or about the variety of traffic detectors available or
how they work consider reading How
does a traffic light detect that a car has pulled up and is
waiting for the light to change?
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