Next time you’re out driving, whether on the highway or a quiet residential street, take a moment to look down at the road. You’ve probably seen those black cables lying across the pavement. While they’re safe to drive over, you might find yourself wondering: what are they for?

It’s a question many drivers have, and today, we’re here to finally give you the answer!

These black cables are actually road tubes, a simple yet effective tool used by local transportation agencies to collect data about traffic patterns. They’re strategically placed in areas where they won’t interfere with traffic but can still gather valuable information.

Here’s how they work:

Whenever a car drives over the tube, its tire causes a burst of air to travel through the rubber tubing to a nearby counter. This counter tracks the data, helping agencies gather information about the flow of traffic. After a set period, the data is collected and analyzed.

The road tubes don’t just count how many cars pass—they also help determine things like peak traffic times by measuring the interval between air bursts. When used in pairs, the tubes can even track vehicle speed, class, and direction.

This data is then used by transportation agencies to make decisions about things like speed limits, road signs, and other traffic-related changes. All of this is done without much human involvement, making it a cost-effective and efficient way to gather important traffic data.

So, next time you spot those black cables, you’ll know exactly what they’re up to!