Author Topic: Speeding NIP incorrectly calculating speed?  (Read 103 times)

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Speeding NIP incorrectly calculating speed?
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Hi everyone.

I just received a NIP alleging I was driving 80 on a dual carriageway. I went to check the evidence as I remember potentially being a bit over the 70 limit for a moment and then reducing my speed.

What I noticed was that the first picture shows a long distance picture of a car which looks similar to mine but the number plate isn't legible going at 80mph with a timestamp of 12:26:05 and D=0352.7m. The second picture has my actual car (number plate is legible) in a different lane to the car in the first picture going at 64mph with a timestamp of 12:26:14 and D=0079.4m.

I assume D is distance, so I calculated that the distance between the 2 pictures is 273.3m and that there is a difference of 9 seconds so the average speed over that 9 seconds is approximately 30.37 m per second which is roughly 109.32 km per hour or 67.9283 mph.

If I assume that the first picture is indeed my car, don't these calculations prove or at least reasonably suggest that I was in fact driving at below the 70 speed limit? Is this a reasonable defence?

Many thanks for any comments or suggestions!

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Re: Speeding NIP incorrectly calculating speed?
« Reply #1 on: »
Without the pictures or knowing what sort of camera was involved it's impossible for us to say.  (Or at least give the location)

However, using such time over distance calculations where an instantaneous capture method was employed is generally fruitless.

Re: Speeding NIP incorrectly calculating speed?
« Reply #2 on: »
Without the pictures or knowing what sort of camera was involved it's impossible for us to say.  (Or at least give the location)

However, using such time over distance calculations where an instantaneous capture method was employed is generally fruitless.

Thanks, the calibration certificate says the camera is a Kustom LaserCam 4 Speed Meter and it was on the A11 around Red Lodge, Suffolk.

Re: Speeding NIP incorrectly calculating speed?
« Reply #3 on: »
The time displayed is "live". The speed and distance are not. The distance travelled between the 2 pings could well be greater than the difference in the distances, and using whole seconds as a unit of measurement over ~9 seconds adds a potential error of +/- 11%, in addition to the uncertainty as to when the distances were actually measured.
I am responsible for the accuracy of the information I post, not your ability to comprehend it.

Re: Speeding NIP incorrectly calculating speed?
« Reply #4 on: »
Without the pictures or knowing what sort of camera was involved it's impossible for us to say.  (Or at least give the location)

However, using such time over distance calculations where an instantaneous capture method was employed is generally fruitless.

Thanks, the calibration certificate says the camera is a Kustom LaserCam 4 Speed Meter and it was on the A11 around Red Lodge, Suffolk.
...then your time over distance calculations won't provide a defence.

Your speed was measured virtually instantaneously (Around 1/3s) - that peak/measured speed is all that matters.

Re: Speeding NIP incorrectly calculating speed?
« Reply #5 on: »
Without the pictures or knowing what sort of camera was involved it's impossible for us to say.  (Or at least give the location)

However, using such time over distance calculations where an instantaneous capture method was employed is generally fruitless.

Thanks, the calibration certificate says the camera is a Kustom LaserCam 4 Speed Meter and it was on the A11 around Red Lodge, Suffolk.
...then your time over distance calculations won't provide a defence.

Your speed was measured virtually instantaneously (Around 1/3s) - that peak/measured speed is all that matters.

Thanks for clarifying that.

In the first picture (around 350m away) the car's number plate isn't legible but in the second picture (around 80m away) it is legible but the car is in a different lane. It seems to me that unless there is video footage of the car from the first picture moving into the other lane and showing the number plate coming into view, it can't be proven that the car going over the limit in the first picture is the same one as the car in the second picture which is under the limit. Do you know if that camera records video footage and can I request it as evidence?

Re: Speeding NIP incorrectly calculating speed?
« Reply #6 on: »
Do you know if that camera records video footage and can I request it as evidence?
Yes it does.  Short of rejecting all out of court offers (Course/Fixed Penalty) they are unlikely supply any such footage.  (Then you are subject to court sentencing if convicted)