this post was submitted on 28 Apr 2024
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What is this thing?

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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.

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[–] [email protected] 0 points 5 months ago* (last edited 5 months ago) (2 children)

It's for traffic count. IIRC the double track to is differentiate the count between passenger cars and semi-trucks (aka tractor trailers, 18 wheelers). The double track can differentiate when there are multiple axles like you see on semi-trucks. Sometimes you want separate counts.

You could calculate speed for shits and giggles but it's not enforceable obviously.

[–] [email protected] 2 points 5 months ago (1 children)

It's not for enforcement...this will tell them if they can 'make profit' by putting up auto ticketing systems that fine you when speeding.

[–] [email protected] 4 points 5 months ago

Yes it's not for enforcement, that's why I said it's not enforceable. And that it's for traffic counts.

[–] [email protected] 2 points 5 months ago (1 children)

They generally only use a single one for counts. You use the double setup here for speed tracking.

[–] [email protected] 2 points 5 months ago (1 children)

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.

[–] [email protected] 1 points 5 months ago

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.