Flashed by Camera when driving under limit?

[andrewparker]

I thought they had to give you 10% as the speedo could be out

Your speedo can over-read by 10%, but not under-read. So it can show you to be going faster than you actually are, but not vice versa.

[Nodz]

I thought they had to give you 10% as the speedo could be out

Your speedo can over-read by 10%, but not under-read. So it can show you to be going faster than you actually are, but not vice versa.

Ah right, I never knew that, I just assumed where speed camera's are generally set 10% +2/3mph I thought it was due to speedo's being out but obviously not

[garrardrj]

Why are you legally allowed to be doing 35mph in a 30mph zone?

Because the law states you are allowed 10% plus 2MPH over the legal limit before you can be issued a speeding fine to allow drivers some breathing space.

So why have 30 mph speed limits then and not just say 35mph but if you break this one we will really prosecute you.

My mates missus got done in Wales where they have no tolerance and probably a different wording in their Highway Code to reflect that...

A different Highway Code  

I know they speak funny and spell funny but their code is the same

People can be prosecuted for 1mph over , the trouble with that is that Speedometers are not that accurate. Therefore there would be more people appealing or fighting their cases . Most forces have the 10% rule , don't know about the plus 2mph bit though . Wales have a zero tolerance and i think that was when Mr Brunstrom was their Chief Constable , he was a nutter (or another word !) He's not there now , he was the one who showed the decapitated head/helmet of a motorcyclist in a publicity campaign to get people to slow down . He hadn't told the deceaseds relatives about it  

[Tamiyoman]

If you took that to court tho I am pretty sure it would have been shown the door, no way they should be doing you for 31 as manufacturers speedos camnnot be guaranteed as accurate hence the allowances

[jonnym]

When the cameras down its not active. Any flashes are merely tests or resets. If you were to receive anything a check using the marks on the road would confirm your speed as either under or over.

What has been said is all correct but just in case the 10% + 2 is merely is guidance issued by ACPO roads policing committee and people have been stuck on for less. The Welsh highway code is exactly the same as England's.

What area was this?

[andrewparker]

If you took that to court tho I am pretty sure it would have been shown the door, no way they should be doing you for 31 as manufacturers speedos camnnot be guaranteed as accurate hence the allowances

It's the law that they cannot read under, so if a Gatso registers you doing 31 mph your speedo isn't allowed (by law) to show anything less than 31 mph, but is could read 34 mph.

[MC71]

My only points (ever) were for doing 34mph in a 30mph zone about 20 something years ago. Still annoys me to this day when I travel on that stretch of road. 

[sub39h]

If you took that to court tho I am pretty sure it would have been shown the door, no way they should be doing you for 31 as manufacturers speedos camnnot be guaranteed as accurate hence the allowances

It's the law that they cannot read under, so if a Gatso registers you doing 31 mph your speedo isn't allowed (by law) to show anything less than 31 mph, but is could read 34 mph.

mathematically this scenario isn't really all that likely. if you're telling me that not a single one overreads then i find that impossible to believe. generally speaking, when talking about averages that are normally distributed, if 95% of the population conforms then you say that it's mathematically significant. speedo variance is likely to be normally distributed, so therefore almost by definition around 5% of speedos are going to overread.

considering that 95% is enough for doctors to decide what drugs to give you, i think it's unlikely that speedos are expected to meet a more stringent test (tho it is possible i suppose). but let's call it 0.5% of cars.

now consider the millions of cars that VW makes. in 2011 VW sold 8.3m cars according to the BBC. what is 0.5% of that? (41500.) i don't think you can have a law against it when talking about that number of cars. and that's just from a single auto maker.

[Deako]

If the camera was in the down position, it's likely that it was pointing at the ground.

[Mr Savage]

So why have 30 mph speed limits then and not just say 35mph but if you break this one we will really prosecute you.

My mates missus got done in Wales where they have no tolerance and probably a different wording in their Highway Code to reflect that...

Without wanting to get caught up in all the technicalities of this i'll just say that yes it's not strictly law that you can do 10% of the speed limit plus 2 MPH but it is in the Police ACPO Guidelines that you are allowed to do 10% plus 2 MPH before being prosecuted in a court of law. I'm sure a Policeman can pull you over for doing 31 in a 30 zone and issue you a ticket but most people would appeal against this and there's a big chance the judge would simply laugh at this and just throw the case instantly out.

The reason the limit says 30 and not 35 is because if it said 35 everyone would drive 35 and there would be no leeway at all for people going slightly over the speed limit, which would be stupid, slip of a foot at the wrong time and you'd get a ticket. So allowing drivers a 10% plus 2MPH tolerance is fair so they can't complain when they get ticket'd for doing 36 in a 30 zone.

Thirdly, this is talking about being caught by a Speed Camera, not a Police Man. Speed Camera's are calibrated to the 10% plus 2 MPH rule and so a 30 MPH speed camera will not go off at 31MPH but rather 36 and above. Can you imagine how many people they would catch if it was calibrated to flash anyone going 1MPH over 30? They'd have a field day. It's the same on motorways, you can drive 79MPH before being prosecuted as again it's 10% plus 2.

I don't know if the rule is different in Wales but i'm in England and I know that this is the case here.

When the cameras down its not active. Any flashes are merely tests or resets. If you were to receive anything a check using the marks on the road would confirm your speed as either under or over.

What has been said is all correct but just in case the 10% + 2 is merely is guidance issued by ACPO roads policing committee and people have been stuck on for less. The Welsh highway code is exactly the same as England's.

What area was this?

The camera was in Derbyshire.

So bottom line. Yes the legal limit is 30 and you can be prosecuted for going over it but the chances are very slim and the chances of the prosecution holding any ground and sticking is even slimmer. Is the guideline 10% plus 2? Yes and this fine will stick if your caught exceeding this.

Oh and lastly I was doing 28MPH anyway so the 35 in a 30 thing is completely irrelevant anyway.

Thanks for everyones help and for putting my mind at rest :) Think it was just testing, faulty, whatever the case. Guess thats why they were fixing it.

[andrewparker]

If you took that to court tho I am pretty sure it would have been shown the door, no way they should be doing you for 31 as manufacturers speedos camnnot be guaranteed as accurate hence the allowances

It's the law that they cannot read under, so if a Gatso registers you doing 31 mph your speedo isn't allowed (by law) to show anything less than 31 mph, but is could read 34 mph.

mathematically this scenario isn't really all that likely. if you're telling me that not a single one overreads then i find that impossible to believe.

I didn't say they didn't over-read. In fact, by law they are allowed to over-read by 10%. They aren't allowed, again by law, to under-read, that is show you to be going slower than you actually are.

Vehicle construction and use regulations require a vehicle speedometer accuracy to be in the range of -0->+10%. The implications are that it must never under-read - for obvious reasons - but may over-read. As the cost of manufacturing a speedometer with -0% error would be very costly they all over-read by a few percent without exception. Even if speed is measured correctly the display may not be accurate, so a speedometer error is allowed. Because of this, the Association of Chief Police Officers (ACPO) have an official formula for calculating a speeding offence. It allows a leeway of 10% plus 2mph. In reality, most speed traps are triggered at higher speeds than this because if they were set bang-on those guidelines, the sheer amount of paperwork generated would overrun the police speeding departments.

[Horatio]

Hey all,

Some help needed to ease my mind. I was driving down a road I use daily and saw the 30MPH camera had been lowered down to the ground and had a van and a bunch of guys all working on it. I drove past it at 28mph and looked in my rear view mirror to be horrified when I saw it flash me twice? Haha.

Any ideas why it would have done this and how I would go about disputing this if I do get a ticket. I know I'm legally allowed 35 before it triggers. Will they notice its a faulty camera/reading before sending the ticket out or will I have to wait and dispute it when it arrives?

Cheers,

Are you a borrower?  

Remember, your speedo will only ever read TRUE, as required by Statute Legislation  , and not give your actual speed. Actual speed and true speed as two very different things.

[sub39h]

If you took that to court tho I am pretty sure it would have been shown the door, no way they should be doing you for 31 as manufacturers speedos camnnot be guaranteed as accurate hence the allowances

It's the law that they cannot read under, so if a Gatso registers you doing 31 mph your speedo isn't allowed (by law) to show anything less than 31 mph, but is could read 34 mph.

mathematically this scenario isn't really all that likely. if you're telling me that not a single one overreads then i find that impossible to believe.

I didn't say they didn't over-read. In fact, by law they are allowed to over-read by 10%. They aren't allowed, again by law, to under-read, that is show you to be going slower than you actually are.

Vehicle construction and use regulations require a vehicle speedometer accuracy to be in the range of -0->+10%. The implications are that it must never under-read - for obvious reasons - but may over-read. As the cost of manufacturing a speedometer with -0% error would be very costly they all over-read by a few percent without exception. Even if speed is measured correctly the display may not be accurate, so a speedometer error is allowed. Because of this, the Association of Chief Police Officers (ACPO) have an official formula for calculating a speeding offence. It allows a leeway of 10% plus 2mph. In reality, most speed traps are triggered at higher speeds than this because if they were set bang-on those guidelines, the sheer amount of paperwork generated would overrun the police speeding departments.

I meant under read. As in display a speed lower than the one you're travelling at. Mathematically this is as near as impossible for me to not believe that there is a law against it.

Your quote also makes no mention of this being governed by law. In fact your quote implies that it is not governed by law, and the Police have to take into account that a percentage will under read

[andrewparker]

I'm not making it up, there are literally hundreds of links that confirm what I've been saying...

http://www.speedview.co/forum/Thread-How-accurate-is-my-factory-speedo

http://www.civinfo.com/forum/general-discussion/25148-speedometer-readings-honda-official-line.html

http://www.thecarexpert.co.uk/how-accurate-is-a-car-speedometer/

[sub39h]

well whether it's a law or not is a moot point. my point was merely that it's mathematically not possible that not a single car manufactured today has a speedo that under reads so as a law it means nothing.

iirc a chap a few years ago also got out of a driving ban for driving over 100mph as it was demonstrated by his legal team that his speedo was under reading. it does happen (it has to happen mathematically speaking), and as mentioned even if it's mathematically a very small percentage over the millions of cars produced yearly it is a significant number of cars.