What You Should Do When You See Black Cables on the Road

The other day, while driving to get groceries, I rolled over a pair of black rubber cables stretched across the road—the kind you barely notice as they make a soft thunk-thunk under your tires. My sister, riding with me, suddenly asked, “What are those for?” I had no idea.

Later, I Googled it—yogurt spoon still in hand—and found out they’re called pneumatic tubes

. Their job? Counting cars. When a vehicle passes over, the pressure sends a puff of air to a sensor that logs it. One tube simply counts cars; two can measure speed, direction, and even vehicle type. This data isn’t just collected for fun—it’s used by city planners to make real decisions: where to place stop signs, adjust traffic lights, or add turn lanes.

It helps identify speeding hotspots and even shapes public transit and snowplow schedules.

What amazed me most is how quietly it all happens. These tubes don’t flash or beep; they just sit there, quietly shaping our roads.