can police work out your speed from dash cam

[Haggisman]

I would imagine theoretically possible, but the effort involved would make it extremely unlikely purely to get someone for a doing a little bit over the limit on the motorway

Lol yes you're right

Erm around 80'ish

"80ish" indicated would be around 72-5 actual speed

I suppose they could take two static objects from your video, go out and measure the distance between them and then time how long it takes you to get from to the other. From that they could calculate a rough speed.

wouldn't that involve finding the exact place where the OP was driving, and then measure the distance between those 2 objects exactly parallel to the path the OP took (including lane changes etc)?

Then there's also the assumption that the camera has a high enough framerate to accurately measure the speed to within the tolerances required to prosecute.

As I said, it's probably technically possible given the right circumstances, but I would place money on it not being worthwhile just to give someone 3 points and £100 fine for being 10 miles over the limit on the motorway.

 

[Illgresi]

You would have to know the exact distance between two external landmarks and measure the time taken for a local landmark to cross them. For example, you could measure a lamp post and a sign post in relation to a chip in the windscreen. However the stretch of road would need to be straight, or the two external landmarks would need to be fairly close together.

Also, according to NPCC guidelines, the police tend not to issue a ticket unless you are driving above 79 m/hr. Taking in to account dial error, it's unlikely they would take the time to bother.

 

[Terminal_Boy]

Bus ran a red light right, joining the road I was on forcing me abd others to stop then just stopped in the outside lane of a dual carriage for around a minute then cut across the inside lane to take a left turn to a side street. And no you can't see not sure of the legalities of uploading something the police have requested, plus just watched the full journey on the the laptop and I was over taken quite a few times so don't think I have any worries.

The bus company would be very interested in seeing your dashcam footage as this driver is going to cost them a lot of money at some point if he/she continues to pull stunts like that.

 

[tom_e]

Also unless you're literally warp speeding past everything else like they're stood still then it's going to look totally normal speed on a M way even if you were knocking on the door of a ton.

 

[VincentHanna]

An indicated 80? If so you were only just doing over 70 so they won't even notice.

Is this still the case? Anytime I go past those 'flashing speed's signs that warn you about speed it always syncs to what my speedo says. I thought there was only about 2%-3% margin of error now on modern cars.

 

[tom_e]

Is this still the case? Anytime I go past those 'flashing speed's signs that warn you about speed it always syncs to what my speedo says. I thought there was only about 2%-3% margin of error now on modern cars.

I think up to 10% over read is allowed, my bike is exactly 10% over when compared to GPS.

 

[kindai]

This thread is worthless with out video.... come on, show us what the fuss is about.

 

[Puzzled]

On a similar note. Anyone heard of any cases where an owners dashcam has been used against them as evidence?

I'm assuming that the police could quite easily confiscate one if they wanted it to assist with an incident.

 

[tom_e]

On a similar note. Anyone heard of any cases where an owners dashcam has been used against them as evidence?

I'm assuming that the police could quite easily confiscate one if they wanted to assist with an incident.

I've not heard of a dashcam being used, but a helmet cam from a biker was used to put him away for 2 years for speeding and wheelies

 

[Burnsy2023]

I thought that to be able to give a penalty for speeding the police need to use a calibrated device that is very accurate. Your dash cam would not be accurate enough. But what do I know?

No, Police do not necessarily need a calibrated device to get a speeding prosecution. They do it because it makes prosecutions simpler to prosecute with much less wiggle room for defences which would be costly to mitigate.

You also need to remember that you only need to prove that the speed limit was broken. If you use a dashcam, you may have to leave a wider range of accuracy but the faster you go above the speed limit the less this matters. For example, if from a Dashcam I expect that my margin of error is 20% and I estimate that you're doing 100, it's still easy to prove you were well above 70mph. This would likely be enough for a prosecution.

Would this happen for a speeding offence? Unlikely. Would it be used in a more serious incident where there was a collision with an injury, especially serious? Rather likely.

I'm assuming that the police could quite easily confiscate one if they wanted it to assist with an incident.

Yes, s19 of the Police and Criminal Evidence Act gives power of seizure.

 

[Ace Modder]

why not just cut the video to only the part in question with the bus, and provide them with that?

 

[Mercenary Keyboard Warrior]

Yes, s19 of the Police and Criminal Evidence Act gives power of seizure.

Surely its just evidence so they can hold it just the same as any other evidence of crime should they feel the need.

Do you think that if they wanted it, say you saw a significant event, that they would just accept the SD card or do you think they would want the whole device?

 

[Burnsy2023]

Surely its just evidence so they can hold it just the same as any other evidence of crime should they feel the need.

Do you think that if they wanted it, say you saw a significant event, that they would just accept the SD card or do you think they would want the whole device?

Indeed, s19 is a general power used for all sorts.

It depends how tech savvy the officer is and whether they're seizing the car after a collision anyway.

 

[Soundood]

Thanks very helpful, just because I prefer digital spy it's a hacked account

to be fair, no activity for 7 years, then this question? what did the gang at digital spy think?

 

[Captain]

A tad over 70 isn't 80ish..

 

[savagesam117]

On a similar note. Anyone heard of any cases where an owners dashcam has been used against them as evidence?

I'm assuming that the police could quite easily confiscate one if they wanted it to assist with an incident.

Yes, a guy I work with friend, went to jail. He was doing 130mph on the motorway about 15 minutes before he witnessed a crash and then gave the film to the police and they done him for speeding as he had one of the GPS fancy ones. Poor guy!

 

[VincentHanna]

Since I've had my GPS dash cam I tend to set my cruise control to 77mph on Dual carriageways and Motorways...

 

[Janesy B]

Stick it on Youtube and let the internet do it's thing.

 

[bobbyspangles]

They can. My brother got a fine once based on a motorcyclists dash footage who had been involved in a fatal accident.

They worked out my brothers speed (incorrectly ) from the length and number of white lines passed.

 

[Uther]

Since I've had my GPS dash cam I tend to set my cruise control to 77mph on Dual carriageways and Motorways...

Still speeding though isn't it? A friend of mine got done for not much over 70 in, I think, Cumbria, so now sets his cruise control to 71 there...