Amateur video footage - sufficient evidence for speeding?

[sunnydude]

Hi guys

If a pedestrian is filming a vehicle travelling in excess of the speed limit on his mobile phone, can that serve as evidence of speeding given that no other offence was committed?

This is of course a theoretical situation which in no way relates to an event that has previously occurred

[KungFuPanda]

Doesn't the evidence have to be someway calibrated?

[sunnydude]

I have no idea

I was thinking more if, say, a car looks like its going too fast

Or if they say that you've covered a certain distance within a certain number of video frames at a certain frame rate (but the phone wont be calibrated)

[Red Devil]

If dashcam footage can be used for successful prosecutions I don't see why mobile phone footage couldn't be.
http://www.dailymail.co.uk/news/article-3344563/Da...
http://www.dailypost.co.uk/news/north-wales-news/w...
Neither of those instruments was calibrated.

[sunnydude]

With the first one, that isn't speed related so no calibrated instrument was required to determine a speed

But with the 2nd one, it said special software had been used to determine speed
However... The charges against him were 2x dangerous driving and 1x careless driving. Is this significant at all? In other words, maybe they could guestimate his speed such that he was in dangerous driving terratory and so only do him for that rather than directly go after him for speeding where he could then question the accuracy of the speed-determining software?

I'll be interested to know about the careless driving charge as well. Is that being used instead of a speeding charge, as a way to sort of avoid getting into a court battle over the validaty of evidence?

Edited by sunnydude on Friday 3rd June 03:13

[AH33]

Just say you must have been photoshopped in

[wgl2014]

sunnydude said:

Hi guys

If a pedestrian is filming a vehicle travelling in excess of the speed limit on his mobile phone, can that serve as evidence of speeding given that no other offence was committed?

This is of course a theoretical situation which in no way relates to an event that has previously occurred

Evidence is evidence........if in isolation that would be enough to secure a conviction is another matter.

I would suggest that it would be more likely to support careless/ dangerous driving or even a S59 warning be handed out. This would also depend on how clear the footage is, does it identify the driver and what it shows. If the vehicle is a few MPH over the limit that is different to doing warp speed in a residential street.

[tapereel]

sunnydude said:

Hi guys

If a pedestrian is filming a vehicle travelling in excess of the speed limit on his mobile phone, can that serve as evidence of speeding given that no other offence was committed?

This is of course a theoretical situation which in no way relates to an event that has previously occurred

Of course it can, all you need is someone to evidence the speed from it, how it was calculated and what the potential errors are.

[Monkeylegend]

sunnydude said:

Hi guys

If a pedestrian is filming a vehicle travelling in excess of the speed limit on his mobile phone, can that serve as evidence of speeding given that no other offence was committed?

This is of course a theoretical situation which in no way relates to an event that has previously occurred

So were you trying to impress a potential girlfriend with speed?

[sunnydude]

No, I haven't done anything
I was just discussing the theoretical situation with a friend

[agtlaw]

KungFuPanda said:

Doesn't the evidence have to be someway calibrated?

Calibrated - no. Corroborated - yes.

[sunnydude]

agtlaw said:

Calibrated - no. Corroborated - yes.

When you say corroborated, what do you mean exactly?

[boobles]

I would have thought that unless the device actually records your speed, then how could it possibly stand in court? unless it's so obvious that you were doing lets say 70 in a 30.
Surely that's like going to the police & saying "somebody drove past me at high speed & was definitely breaking the speed limit"

[agtlaw]

See section 89(2) RTRA 1984. Corroboration requirement for non-motorway offences.

It would "stand in court" by taking two known points a known distance apart and doing the maths.

Edited by agtlaw on Friday 3rd June 10:29

[sunnydude]

agtlaw said:

See section 89(2) RTRA 1984. Corroboration requirement for non-motorway offences.

If would "stand in court" by taking two known points a known distance apart and doing the maths.

Edited by agtlaw on Friday 3rd June 10:28

But as its speed = distance/time, would the video recording speed from the persons mobile phone be accurate enough? Surely the phone's video recording timecode inaccuracy could possibly make the car be calculated to be going faster than it actually was, let alone the fact that it could have been sped up with a video editing app

I suppose the other thing could be the 14-day rule. If it applies in such situations, and they miss the 2 week window for reporting it to the police, surely they could simply just edit the metadata on the video to make it appear as if the incident happened later on?

Also, i've just seen on your profile that you're a barrister. Do such like cases happen often?

Edited by sunnydude on Friday 3rd June 10:44

[silentbrown]

sunnydude said:

Surely the phone's video recording timecode inaccuracy could possibly make the car be calculated to be going faster than it actually was?

Or slower, of course.

But how accurate is the clock on your mobile phone? They'll normally drift out by a few seconds a day and resync from a central server or GPS. Imagine that your phone lost a massive one hour every day, that's still only a 4% error, so a true 50 MPH would be calculated as 52MPH.

There's inaccuracies in every method of measuring speed. Some are worse than others. From film footage the main difficulty might be correlating the position of the car in the video to an exact position on the road, which will deopend on the camera angles, length and quality of the video.

However, any inaccuracies can be calculated, to give you a margin of error of +/- so many percent.

[Mr Happy]

Surely number of frames for the car to travel between points a and b on the video / fps of the video = time, then measure the distance between point a and b shown on the video = distance, and work the speed out from that?

[sunnydude]

Mr Happy said:

Surely number of frames for the car to travel between points a and b on the video / fps of the video = time, then measure the distance between point a and b shown on the video = distance, and work the speed out from that?

Yeah, thats how it will be done.

I did exactly that for my 3rd year project at uni when measuring the speed of vortex rings using frame numbers. Whilst I know that it works, i'm also aware of things like eg. Parallax errors

[jith]

So where is the evidence of dangerous driving, or is it once again an assumption simply due to the calculated speed?

J

[tapereel]

sunnydude said:

Mr Happy said:

Surely number of frames for the car to travel between points a and b on the video / fps of the video = time, then measure the distance between point a and b shown on the video = distance, and work the speed out from that?

Yeah, thats how it will be done.

I did exactly that for my 3rd year project at uni when measuring the speed of vortex rings using frame numbers. Whilst I know that it works, i'm also aware of things like eg. Parallax errors

The video frame rate is very accurate and more so than it needs to be to calculate vehicle speed over a few 10's of metres.
If there is potential for parallax errors it is up to the witness to either remove that by careful analysis or account for its quantity.
All easily achievable if you know what you are doing.