I mean, I think pneumatic road tubes are far more effective for capturing cleaner data on vehicle speeds over time, since they are less visible and likely unnoticed by many drivers. They aren’t there to fine drivers, but I’m sure with a small hidden camera, they could work in the same way. Not sure why speed cameras are so visible, since people almost always in my experience, will speed back up after leaving the area of the speed camera, negating the benefits swiftly.