What are those long black tubes in the road used for?

Have you ever been driving down a road when you are suddenly confronted by a long, black tube that is stretched across the entire street?

Although it may look like nothing more than a displaced garden hose, it actually plays a very important purpose — one that could impact whether or not you end up getting a speeding ticket in the future.

So what is this mysterious tube, who put it there and how does it work?

It’s called a pneumatic road tube and according to the U.S. Office of Highway Policy Information, when a car passes over one of them, it releases a burst of air pressure.

City of Bloomington, Minnesota

This pressure, in turn, sets off an electric signal, which delivers information to analysis software.

Using these tubes can help highway officials to determine how many drivers use a road per day, as well as which direction they are traveling and during what times of day.


The information collected can be helpful in figuring out patterns of traffic as well as what class of vehicle (cars versus tractor-trailers, for example) uses that road.

“We use [traffic counts] as an important statistic for roadway planning and design,” said Matt Bruning, a spokesperson for the Ohio Department of Transportation, when talking about the tubes to the Marion Star.

The video below, from the City of Bloomington, Minnesota, shows how the tubes are installed and what keeps them in place.

The information collected by the tubes could also include the speed at which drivers travel, which is important in determining if a certain road is experiencing a high rate of speeding, or unsafe, drivers.

For example, do you live on or near a street where you feel that drivers are going too fast or not paying enough attention to road signs?


When a community has complaints such as this, road safety officials can use pneumatic road tubes to help determine if risky driving is a common occurrence on a patch of road.

If the analysis shows that that people are driving too fast, state transportation officials might decide to hang up new road signs, such as clearly marked speed limit signs or signs that urge drivers to slow down.


This information might also be shared with local police, who could decide that they need to keep a closer eye on a certain street and hand out more tickets to speeding drivers.

So, the next time you are driving down the street and you see a bit of tube stretched across the road, keep this information in mind.

When Should You Actually Merge?

When you’re driving down the road and you see that one lane is ending soon, do you get over right away? Or do you wait until the last second (which tends to make other drivers really angry)?

traffic photo
Getty Images | Scott Olson

Merging early is like waiting in line at the deli — you wait your turn to go through the construction zone like everyone else. But merging late feels like you’re cutting the line and making life unfair for the rest of the drivers. Also, no one likes getting the one-finger salute from other drivers.

According to multiple studies though, it turns out you’re supposed to merge at the last second.

traffic photo
Getty Images | Marc Serota

Staying in your lane and moving over at the last second is called the “zipper method,” and it’s the most efficient method of merging.

From above, it looks like a zipper being zipped up, since every other car takes their turn through the open lane. Studies say this can reduce congestion by 40% while also causing fewer accidents since every car is going at the same speed.

RELATED: Would you or do you use one of these devices to monitor your teen on the road?

Have you learned something about driving today?