You’ve seen them.
They stretch across the asphalt like black rubber snakes, lying quietly in the road.
You drive over them.
Thump. Thump.
No warning signs.
No cones.
No workers in sight.
Just two mysterious black tubes — and the quiet sense that something is happening… but you have no idea what.
I used to ignore them too — until my sister asked, “Wait… what are those?”
And I realized:
I had no idea.
So I did what we all do:
I Googled it later, yogurt spoon in hand, still in my sweatpants.
Turns out, those unassuming black cables aren’t forgotten construction debris.
They’re pneumatic road tubes — silent, low-tech sensors that count cars, measure speed, and help shape the way cities move.
And yes — that thunk under your tires?
That’s your car being recorded.
Let’s explore what they really are, how they work, and what you should know the next time you see them.
🛠️ What Are Those Black Cables? Meet the Pneumatic Road Tube
Those black rubber tubes you drive over are temporary traffic counters — part of a system used by transportation departments, city planners, and engineers to collect real-world data.
They’re called pneumatic tubes because they work using air pressure — no electricity, no cameras, no satellites.
Just rubber, air, and physics.
🔧 How They Work – Simple, But Brilliant
Here’s the magic:
