Rubber tubes across NJ roads are tracking more than you think
I predate the internet. God how I wish I didn’t!
Nonetheless, when I was a kid, if you were really curious about a thing you had to find a local library (remember those things?) and spend time finding books and scouring pages looking things up.
So maybe I just grew so used to wondering about an unimportant thing and being content without an answer that it took me forever to finally Google this one.
Ever wonder about those thin, easy to miss black rubber tubes you’ll see stretched across a traffic lane on a road surface? Sure, we know it must be the city or county or state taking some sort of car count. But was there ever more to it? Why do we sometimes see a second tube spaced so many feet after the first one?
Well I finally looked it up.
Turns out they’re called pneumatic road tubes. They’re more involved than you’d think. And can tell a lot more than just how many cars drove over them.
They are stretched across a road perpendicular to traffic. They’re closed at one end and secured in place by a nail in the pavement. The other end travels into an electronic box powered by rechargeable batteries and the box is out of sight and usually chained to a street sign or pole.
Every time the pressure of tires hits the tube it sends a burst of air through it which records the event in that box. Simple enough way to know how much traffic a certain road is getting.
Turns out they do much more.
Check out this video:
You will sometimes see that second pneumatic road tube placed several feet after the first. This will tell you by whatever fraction of a second the second air burst comes after the first precisely how fast your car was being driven.
Now luckily there are no cameras and this is never a moving violation machine for police. We had our fill of red light cameras. We don’t need electronic speed enforcement like they have in Maryland. But no worries. This is purely to collect data which can be used to determine if a speed limit needs to be adjusted or possibly better enforced.
These tubes can tell which direction traffic is headed. They can even tell by the spacing apart of axels what vehicle classification is rolling over them. So they will know a passenger car from a box truck and a box truck from an 18-wheeler. Pretty cool.
They say these pneumatic road tubes are usually placed only temporarily and often for only one day of data gathering.
Now if they could only tell me why my check engine light is on.
The post above reflects the thoughts and observations of New Jersey 101.5 talk show host Jeff Deminski. Any opinions expressed are Jeff Deminski's own.