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're usually not used for speed where I live. They're simply for measuring traffic.
I can think of a few situations where it is used on small roads only to check the traffic without it necessarily meaning that any changes will be made to the small road.
If someone owns a small private road which is open to public traffic and it gets used a lot by people who don't live on that road, it's possible to request a reading of how much traffic passes through to determine if the municipality should take over responsibility of maintaining the road.
If there recently was built a larger bypass it makes sense to check if people still use the smaller roads instead of the bypass for whatever reason.
These things can be used to figure out lots of other stuff about traffic dependent on how and where they're set up, but generally it's that kind of thing. Just traffic measurement.
Speed readings would be incredibly annoying to do this way. While it is technically possible, most of the data would be useless. Sorting through data from several weeks only to be able to determine that someone probably speeded there last week doesn't really give any meaningful information to anyone.
Speed checks are better done with the sort of doppler measurement devices that you might know from the signs that show your speed and blink when you're speeding.
There's almost no reason for having two of them other than to measure speed, otherwise you'd only use one. But it's not for enforcement, it's to see how fast most drivers actually drive the road. This can be used for things like adjusting the speed limit, or testing to see if measures need to be taken to enforce it more strictly, etc. I know there is a hill in my hometown that residents used to always complain about speeding. They used exactly this setup to track the speed of drivers. They found that there was no excess in speeding, the steep hill required more gas to maintain speed, and people generally associate louder engine noise with higher speed.
There's two of them to determine the direction.