Vehicle Counters
Car counters rely on metal detectors. Either an inductive loop is cut into the tarmac road surface itself, or a magnetometer is buried easily in the adjacent grass verge. Installing a loop is a technical job which most highways authorities licence strictly. But on private roads you can do what you like. An inductive loop is only triggered when a vehicle is directly on top of it. By contrast, a magnetometer will respond to any large iron objects moving nearby.
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Magnetometer A magnetometer detects metal passing over or near it. It can be buried on the side of a road and will detect vehicles passing. |
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Induction Loop Induction Loops are loops of fine cable cut into the road surface and will detect vehicles passing. They cannot be used on gravel roads. |
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Pyro The pyro detects a body of heat passing near it. This will work with the heat of a vehicle engine as well. |
