While driving the other day, I spotted some black rubber cables stretched across the road. They made a soft “thunk” noise as my tires rolled over them. I’d seen them before but never really thought about what they were for until my sister asked me. Honestly, I didn’t know. So I looked them up and found out these are called pneumatic tubes, and they have an important job: counting cars.
Each time a vehicle passes over one of these tubes, it pushes a little burst of air through it, which then triggers a sensor that records the vehicle. One tube counting tells how many cars pass by, but two tubes spaced apart can do a lot more. They can measure how fast a vehicle is moving, which direction it’s going, and even tell if it’s a motorcycle, car, or truck.
The data collected doesn’t just vanish. Transportation officials use it to understand traffic patterns, decide where to place stoplights, or figure out if new lanes or stop signs are needed. This information even helps with public transport planning and setting snowplow priorities during winter.
These cables quietly work behind the scenes, giving cities valuable data to improve your daily drive. Next time you see those thin black cables across the road, remember they’re busy gathering information, helping make traffic safer and smoother—without you even noticing.
