Discussion
When i got done by a GATSO, the whole case and my estimated speed was based on the number of lines i had travelled on the road. I'm no expert, but i can't see how they can prove your speed if they can't prove the distance you were travelling?!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
eltax91 said:
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
Quite so. And distance travelled is the difference between the return times of radar pulses emitted by the Gatso. I'm told that the lines a only corroborative, and that the approval doen't require them.
Andrew D said:
eltax91 said:
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
Quite so. And distance travelled is the difference between the return times of radar pulses emitted by the Gatso.Not quite - Gatsos use continuous wave radar, which measures the frequency of the returns from the car and calculates the speed from the doppler shift.
eltax91 said:
When i got done by a GATSO, the whole case and my estimated speed was based on the number of lines i had travelled on the road. I'm no expert, but i can't see how they can prove your speed if they can't prove the distance you were travelling?!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
I think that they can use an overlay on the photo to determine the distance travelled between the flashes.
esselte said:
eltax91 said:
When i got done by a GATSO, the whole case and my estimated speed was based on the number of lines i had travelled on the road. I'm no expert, but i can't see how they can prove your speed if they can't prove the distance you were travelling?!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
Speed = DISTANCE divided by Time if i remember my GCSE maths correctly!
I think that they can use an overlay on the photo to determine the distance travelled between the flashes.
Bummer, so painting over the whites with tarmac-coloured paint won't invalidate them all?
esselte said:
I think that they can use an overlay on the photo to determine the distance travelled between the flashes.
That would be very naughty as such a process is subject to a substantial amount of uncertainty.
No lines on road > no secondary measurement to corroborate with the primary sensor (which is subject to error) > reasonable doubt!
Given there were no lines and the OP's indicated speed was nowhere near the nominal trigger threshold, I would say the camera is a powered dummy.
stevem5 said:
Whilst driving to work this morning, a Gatso flashed at me. When I looked down I was doing 30mph (In a 30 zone). The road in question has only just been re-tarmac'd so there are no lines on the road for the Gatso.
Am I OK?
Am I OK?
When they installed at GATSO in Highnam, near Gloucester, some years ago, it was flashing at everything going above about 25mph in both directions! I don't know if anybody got a FPN for low speeds, but I was flashed twice doing about 32 and didn't hear anything more.
Gatsos require the road markings. If the lines are missing then you get NFA on that one. It must have the calibrated lines in the road to prove the offence. There was recently a case where a motorcyclist was flashed by a camera for doing I think 38 in a 30 limit, and he queried the evidence as he believed it was incorrect. The line markings were not checked by the ticket office before sending the NIP out. At court it was subsequently proved from the photograph that he was actually doing 26 mph, which is why these lines are required to coroborate the offence. 
Gassing Station | Speed, Plod & the Law | Top of Page | What's New | My Stuff