can the police use your dashcam for proof that you were speeding?

I doubt they could get you for speeding unless your cam is an accurate speed measuring device

erm... Once again (amazingly), speed is merely distance over time. A camera is already an accurate time measuring device, then by using the footage an investigator can return to the scene and accurately measure the distance travelled, therefore the speed figure you calculate using this basic equation will automatically be accurate.
 
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I doubt they could get you for speeding unless your cam is an accurate speed measuring device, or you've got your speedo clearly in shot. I can see a traffic cop trying it on, but if you went to court and asked the police to tell you exactly how fast you were going based on your film and their guestimate, they'd look a bit silly saying "fast, but I don't know how fast".

However, if they've got film of you driving like an idiot, crossing solid lines, overtaking at zebras and so on, they'd do you for that instead, regardless of your speed.

If the police are going to use a recording like that in court against you, it would be pretty simple to determine an average speed. It is just distance over time afterall. Not exactly rocket science.
 
erm... Once again (amazingly), speed is merely distance over time. A camera is a completely accurate time and distance measuring device therefore the speed figure you calculate using this basic equation will automatically be accurate.

Establishing the speed of a car from a video is not the biggest challenge associated with obtaining a conviction.
 
Establishing the speed of a car from a video is not the biggest challenge associated with obtaining a conviction.

Like I said, whilst this is possible, most officers have too much work to get that video evidence into a usable state for a conviction.
 
I have a Roadhawk and it tells me how fast I am going at any given time complete with google map reference.

So looking at footage of me doing 110 down M54 I reckon they could do me.

Dave


ps - joking about 110
 
Generally actual police officers aren't that interested in your speed, unless you were going a LOT more than the limit. They leave that to the road-side speed traps. They would be interested in evidence of Due Care and Attention or other such offences though.
 
Like I said, whilst this is possible, most officers have too much work to get that video evidence into a usable state for a conviction.

In a case where the car is stopped at scene and a camera is removed perhaps, but in the case of a YouTube video very hard even with all the time in the world.
 
If the police are going to use a recording like that in court against you, it would be pretty simple to determine an average speed. It is just distance over time afterall. Not exactly rocket science.

But if playback is faster or slower than the speed it was recorded at then there will be a difference
 
Pretty simple to play it back at 1x speed though. Basic software.

I think he's hinting at the fact that it's easily open to abuse, if they play it back faster (intentionally) they could claim you were driving faster.

There would be a limit of how much playback could be sped up of course, but it could be used to push speeds past speed limits without it being obvious that it's been sped up.
 
I think he's hinting at the fact that it's easily open to abuse, if they play it back faster (intentionally) they could claim you were driving faster.

There would be a limit of how much playback could be sped up of course, but it could be used to push speeds past speed limits without it being obvious that it's been sped up.

And therefore committing perjury, perverting the course of justice and misconduct in a public office to name a few likely offences. Jail time would be all but certain.

And you reckon someone would do that to make it look like someone did 35mph instead of 30?
 
how could you be sure that the camera was recording in real time? and not creating footage that was sped up/ slowed down.

it comes down to calibration. speed guns have to be calibrated. police cars have their speedo's calibrated. i doubt that a cheap dash-cam would have any calibration accreditation at all.
 
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