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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.
I didn't have any inside knowledge, but I can't think of what having two would help other than the ability to measure speed. You can count just fine with one.
I should imagine you could measure direction too, if one is tripped before the other.
They may be for calculating speed, but without any further information, there's no way of telling what wheels belong to what vehicle, or how many wheels (edit: or more specifically, axles) a vehicle has - so it certainly wouldn't be viable for enforcement.
You can also estimate the size of the vehicle. based on how fast it it going and the time between front and back wheel you could calculate the distance between the wheels.
with two strips you can get a lot more data than if you just have one. count, direction, speed, size, and times the road is active. I dont know if they active measure all that but its possible.
Good point about direction. I couldn't imagine using this for enforcement, but I'm guessing you could be pretty confident any the number of axels but counting the ones that are the exact same speed and by the distance apart.
With only one, wouldn't the length of the vehicle also be a variable?
That would be the problem for speed, but for counting you'd just look for close sets of pulses.
Oh, I somehow misread that as you saying you could get speed from just one
Ah, no, need two
I have seen cases where two tubes are used, but one only stretches half way, so they can tell which lane is used.
Weight, since if you don't know speed you don't know if it's light and slow or heavy and fast. Number of vehicles, since you can't count axles without the above data