Have you ever seen black cables on the road?

I always thought they were a way for police to see the speed or for speed traps.

Have you ever wondered why they are there?

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If you are as confused as I am, no worries! I am about to explain it all.

Black Cables Meaning


Luckily, the black cables are not something that we drivers need to worry about.

Independent Mail says that,

At times, two parallel cables are deployed. That enables the DOT to determine the speed and type of vehicle (car, bus, or 18-wheel truck). The two-tube counters, also known as Continuous Count Stations (CCS), count vehicles 24 hours a day, 7 days a week.

Every time a vehicle's tires hit the tube, it sends a burst of air that will trigger a switch that makes an electrical signal.

These black cable tubes are extremely important for federal agencies according to Mental Floss:

One pneumatic tube can track the number of cars driving over a road in any given span of time. By measuring the time that passes between air bursts, officials can determine which time of day has the most traffic congestion. Two pneumatic tubes installed slightly apart from each other paint an even broader picture. Using this method, government agencies can gauge the class, speed, and direction of each vehicle that passes through.

Mental Floss
Mental Floss

Based on the data from the tubes, cities, and municipalities can check which road signs and speed limits are actually working or not. It also helps figure out how much money they can allot for their transportation budgets.

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