I know you've seen these on Lubbock roads before, but have you really ever wondered what they are and what they do?

They have the fancy pants name of Pneumatic Road Tube, not funky black snakes on a road.

The United States Department of Transportation describes them like this:

Pneumatic road tube sensors send a burst of air pressure along a rubber tube when a vehicle’s tires pass over the tube. The pressure pulse closes an air switch, producing an electrical signal that is transmitted to a counter or analysis software. The pneumatic road tube sensor is portable, using lead-acid, gel, or other rechargeable batteries as a power source.

They're used not just for counting traffic, but to determine if road signs are needed and if there are speeding issues in a particular area. The sensors can also determine what kind of vehicle and how many axles a truck has.

So, at the end of the day, these sensors serve a lot of different purposes in keeping us safe on the roads of Lubbock.

Oh, and if you ever wanted to see how they do this, then here you go!