The Purpose Of Those 2 Black Cables On Massachusetts Roads

Do you ever come across two random black cables laying across a street or a road here in Massachusetts?

I was on a afternoon jog the other day when I saw a pair nearby a MassDot vehicle.

They look pretty snug to the street, so they're definitely not downed wires or something like that.

What are those things, anyway?

Here's What Those Random Black Cables On The Road Mean

I always thought they somehow measured your vehicle's speed and were to alert local law enforcement of speeding hotspots within a city or town.

Well, I was half correct.

Those two black cables or "pneumatic road tubes" actually do more than just decipher speed, they gather a bunch of information.

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. -mentalfloss.com

The information being recorded from the tubes will give data on the number of vehicles that pass over them, the size of the vehicle, the length (18 wheeler for example), the weight, and the speed at which the vehicles are traveling.

The information being recorded from the tubes will give data on the number of vehicles that pass over them, the size of the vehicle, the length (18 wheeler for example), the weight, and the speed at which the vehicles are traveling.

Sometimes the cables are installed for a short time, (24 hours), while others are left for a while.

Information that is collected can help state or city governments better improve roadways.