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Just for counting? For speed also?
(lemmy.world)
Yeah I know these are used for counting vehicles but can they also be used for detecting vehicle speed?
Description: two pneumatic hoses, affixed to a road. They lead to a box that's locked to a telephone pole. Location is southern California. On a minor artery road.
Doubtful that it's to survey if a new stop sign is needed since the next street is minor, dead ends into this one and already has a stop sign. The next intersection with another minor artery already has a stop sign.
Extremely doubtful that a traffic light is being considered since there isn't anywhere near the amount of traffic to justify one.
This is located on a slope. Many cars speed down here. That's why I'm wondering about speed sensing by this device.
They generally only use a single one for counts. You use the double setup here for speed tracking.
What I'm saying is they use a double to differentiate counts between passenger cars and semi-trucks (aka tractor trailers, 18 wheelers). Sometimes you want a count of 1) passenger cars and 2) semi-trucks. That's what I remember learning it was for. I'll edit my previous reply in case people are misreading it.
You can do that with a single line. It's a closed, flexible tube with a pressure sensor. Effectively a crude scale. It measures the weight on the axle. Semi trucks weigh a LOT more than passenger vehicles, even ridiculous pickups.