Driving to work I ran over one, but it wasn’t there yesterday. All it is, is a long cord that goes across the road with a box at the end. Is it some data collecting device? If so what is the data for?
they count the number of cars going over. it’s done to assess things like traffic patterns, needs to traffic lights etc. Or at least that’s what I was told when I asked.
It’s “Big Brother” at work! Stick it to the man and drive in the ditch.
yup, just an air hose with a sensor at the end recording the pressure “bumps”. You also see them at the entrance to gas stations to ring a bell inside tellling them a car has arrived.
To be accurate, they count the number of axles. Each time one axle goes over the line, the counter goes up. They take the number that gives and divide it by 2, which is roughly the number of cars that go over that stretch of road.
This isn’t entirely accurate, but is a good estimate. They do take into account if, say, the box is near a truck stop that number will be more likely to be 18 wheeler traffic.
One cord is to monitor traffic flow. Sometimes you see two cords a short distance apart, I have been told these are to monitor traffic speed by measuring the time between a signal on the first and the signal on the second. No idea if this is true and if so how it works on multiple lane roads. I’ve never seen a police car around where these cords are placed, so I would guess it is for informational planning purposes, not to catch speeders.
It’s used in traffic studies–mostly to determine if a section of road needs to be widened or expanded.
I’m Dept. of Transportation, so I know.
By the way, Slacker, I wouldn’t do that if I were you. State Police & local Law Enforcement often set up shop to catch speeders near those boxes. This is becaue the nice folks at Transportation ask them to. To see that nobody messes with them. Also, they are checked 4 or more times daily, & results are recorded. If you get caught messing with a field worker’s gear, he may just bend your head with that wrench that’s a part of his standard issue kit.
Also, there will be less State & Federal money to fix roads & pot holes near where you live, 'cause the traffic study’s screwed up.
Wow, what a great sig-line-in-the-making.
There used to be the occasional counters laid out on the road home from my elementary school. We thought it was great fun to jump on the cables and up the count.
The counter itself was visible without unlocking any cover. So we could see that each jump (or car axle) only bumped the unit counter by half a click; e.g., after one jump, the dial would turn to halfway between 1 and 2; one more jump, and it’d go to 2.
So no dividing by two is necessary.
Those things are hopelessly old-fashioned. Nowadays they have devices that can simultaneously determine the speed and type of a vehicle that passes over them. They’re basically metal detectors that generate a plot of signal strength vs. time. The shape of the resulting graph gives the speed of the vehicle and tells whether it’s a car or a bus or a truck or whatever. And, of course, a computer attached to the device keeps statistics on all the traffic that passes over it.
Such devices are nothing new. I saw a catalog of them several years ago (in the men’s room, as it happens) when I was also “Dept. of Transportation.” As far as I know, the only advantages to the older ones are cost and ease of installation. And the fact that juvenile delinquents can jump up and down on them all they want without compromising vital government statistics and causing huge freeways to be built out in the middle of nowhere. (Which happens in Texas anyway.)