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.