I like the idea but in the real world, your screwed!
As I’m sure you know, you can’t measure anything 100% accurately. You can count things but not measure, be it speed, distance, temperature or angles. As far as speed is concerned, the law knows this as well.
Over 150m with the gun offset by 10 m, the difference in distance is about 0.3m. With that fact known, the officer would be able to give a reasonable reply.
I never seen one of the guns (well, not close up
) but it wouldn't surprise me if they have a distomat function that allows the user to swing approx. 90 degrees and measure the offset to the carriageway which can be used in the calculation of the speed. Getting closer to the true speed.
As you have said, loads of other things come into play such as the horizontal and vertical alignment of the road, temperature, air density and the fact that sometimes the gun is hand held.
For the average speed and fixed position camera’s there is a huge amount of testing to be done involving the police, Dept of Transport, the Home Office (I think) and the installers before they can start issuing tickets. Can take up to three months before they become live, hence you don’t see them on road works of short duration (unless they have sped up the process since I was on a motorway project).
I would guess the same has happened for the hand held or camera van device in the form of trials and training, to ensure the prosecution stands up in court.
Any measure of speed will only be a rough estimate hence the 10% plus 2 rule (if it’s true but seems to be). The problem would come when they try and prosecute for 31mph etc. You sometime hear in the press about calls for any amount over the limit to be enforced but they simply can’t do it.
Must say to BoxercupDave, very sorry for the thread hijack btw, should have said this before.
Hope all works out well.
)
