View Full Version : Speed limit tolerances
Paul James
01-Oct-2006, 09:37
Used to be that for speed cameras a tolerance of 10% posted limit plus 2mph was applied. (Actual speed in a 70 zone being 79 before a nick). It was supposedly to allow for speedometer errors.
Can anyone shed any light on whether this has changed ???
doogalman
01-Oct-2006, 09:48
Still much the same i think.
chris.p
01-Oct-2006, 09:49
Why?, have you been nicked Paul???:o
Chris:burn:
I believe the 10% plus 2mph is the ACPO guidelines, and as such are guidelines only, so it is possible to get done below that, but unlikely...
http://www.speedlimit.org.uk/faq.html
Also has a link to the ACPO website and speed enforcement guidelines
Martin
Rossman_999
01-Oct-2006, 10:45
Its cerainly no more Ive got got done for 82 on a 70 in the car! (camera van)
When I did my advanced test with the IAM the examiner said that he would allow 5 mph, which is what a police officer would do.
One other thing he said was that when overtaking he would be watching what was happening not the speedo so make the overtakes quickly and safely and after the manouvere was complete check speed, not during.
Of course he wasnt actually plod or a speed camera !
Athelstan
01-Oct-2006, 12:08
Used to be that for speed cameras a tolerance of 10% posted limit plus 2mph was applied. (Actual speed in a 70 zone being 79 before a nick). It was supposedly to allow for speedometer errors.
Here in CH we have the following:
a) general rule is 5kph tolerance margin allowed and the equipement error is set at 5%. Anyone found speeding more than 30kph (inc the 5kph) over the set limit has licence immediately withdrawn at the roadside and is not allowed to continue their journey in their vehicle which is impounded.
b) in some regions the authorities have introduced some new kit where they say the lazer measuring is so accurate that they have lowered the error margin to 3kph!! In other words virtually nothing (it is 1.875 miles per hour) - BUT - you the motorist have no idea where the new kit is installed.
c) the smallest roadside fine you'll face is approx UK£20 and the largest UK£90 plus an administration fee which will vary according to the Kanton where you were speeding, but expect a Tenner. If you are really thrashing it and above the max speed limit plus 30kph the you'll face a very heavy administration fee +UK£150, plus a court fine upwards of UK£120 to UK£2,000, plus a court fee - minimum UK£60. And if you were really naughty or caused an accident you may face gail as well which may be anything from the weekend to years.
Compared to us the uk is bliss - you lucky people.
Paul James
01-Oct-2006, 23:09
Just seems that as the driver/rider has his/her licence endorsed with penalty points which can lead to a driving ban there should be some national tolerance law ? There must be something to cover the potential inaccuracy of the speedometer and of course the speed measuring equipment ?
Question came up as a guy who does regular van deliveries to us recently got a ticket for doing 76 in a 70 zone, if the 10% plus 2mph was applied he shouldn't have been nicked.
Here in Oz in NSW, a decition has just been handed down in the supreme court, stateing that all the radar trap aquired fines were null and void for the last ten years. This was because the radar guns were required to be calibrated daily by the manufacturer, but the NSW cops did it yearly. This sounds like a bonus, but no. Due to the revenue raised being in the billions of dollars, the case has now moved up to the federal court.
Our cops give no quarter, for speedo error, which frankly sucks. They use to. And the worst part is that they say they are doing it to reduce road toll, but there has been no change since introducing all of the speeding detection equipment.
Griff
Most speedos, particularly the japanese ones error on the side of bravado.......so when your whinging about being caught at only 6 mile an hour over the limit, that will be the correct speed as apposed to you speedo reading which was probably over 80............
So if you used the speedo reading at for example 70 in a 70 i doubt if you would get a ticket.....Still you think they would put a big needle on it and get it to point at the speed your going...:rolleyes:
Paul James
02-Oct-2006, 08:58
Most speedos, particularly the japanese ones error on the side of bravado.......so when your whinging about being caught at only 6 mile an hour over the limit, that will be the correct speed as apposed to you speedo reading which was probably over 80............
So if you used the speedo reading at for example 70 in a 70 i doubt if you would get a ticket.....Still you think they would put a big needle on it and get it to point at the speed your going...:rolleyes:
Think you've missed the point here mate: If there is a tolerance it should be applied nationally. If there is no tolerance it is unworkable law. It isn't about a telling off its about potentially banning people from driving over irrelevant enforcement of misinterpreted, abused law.
In engineering I work to a tolerance, it is on the drawing and in effect part of the contract with my customer. If they decide to accept anything that I produce out of tolerance that is up to them, not me. If I make anything that doesn't conform to drawing it is scrap and they have no obligation to buy it.
Ergo the system of policing speeding should be based on a national tolerance which different regions can't change at a whim. If it is 10% + 2mph of the posted speed limit that is clear and workable fpr all concerned, it is reasonable. Getting nicked for doing 32mph in a 30 or 76 in a 70 isn't reasonable or likely to prevent any accidents IMHO it just alienates the generally law abiding driver yet again.
Isn't the tolerance on a speed limit zero, with discretion given for practicality where appropriate?
Ains.
The guidelines are just that, Guidelines. Some areas are "zero tolerance" so in theory you'd get done for 71.
There is no national hard and fast rule other than the actual speed limit itself, what speed you get done at over that is up to the policy set by the areas chief constable or the officer who pulls you that day...........if his/her moning bacon butty was not to his/her liking or their hair didn't look good on last nights police, camera action prog. you can be in trouble at just 1mph over.
Follow Andy B's advice and don't go over the limit at all or try not to get caught.......tough choice:lol:
Ray.
Or become a copper!
Is that a class 1 Copper? :lol:
.any case, all our vehicles are now fitted with datalogging black boxes! .......and the speed exemption rules have changed...........:eek:
philthy
02-Oct-2006, 11:05
I'm with Ains on this one. The limit is the limit. I drive in North Wales most days and here there is no tolerance level so I do an indicated 29 in a 30. In other parts of the country I still stick to speed limits as best I can.
The problems arise when you are followed by one of the '' I don't agree with the speed limits '' brigade who think that by following 6'' off your back bumper you will go faster, which happens at any speed. I had one at the weekend, maintaining 60mph in the astra van on a lovely twisty Welsh A road and 4wd comes up behind and tailgates for about a mile, ignoring several safe passing opportunities, and eventually overtakes on a blind left hand corner.
I caught him up about 5 miles later on an equally twisty B road where I can maintain 60mph and he was struggling to do 45.:rolleyes:
and of course they are a maximum limit, not a compulsory!:lol:
philthy
02-Oct-2006, 12:12
Ouch :lol: :lol:
Nice to see that you guys are such paragons of virtue. Don't you ever exceed 60mph when you are out riding on country A roads?
You are absolutely right in saying that we should keep within the 30 mph limit in built up areas but to advocate going no faster than 60 seems incredible coming from motorcyclng enthusiasts.
We live and learn.
Paul James
02-Oct-2006, 17:50
Isn't the tolerance on a speed limit zero, with discretion given for practicality where appropriate?
Ains.
How can there be no tolerance on a measurement ?
That was the point I was trying to make really. Who determines what 70mph is for instance ? What is the manufacturers tolerance on the speed cameras ? NOTHING is manufactured without a tolerance whether it be 0.0005% or 10% or expressed as something other than a percentage.
What is the manufacturers tolerance on a speedometer ? What effect does using tyres made by different manufacturers have opn speedometer readings?
Does anyone think that applying a strict 70mph limit has any true effect on road deaths and casualties when it usually goes hand in hand with a serious reduction in the police presence on our roads ? Would you rather have someone drive past your kids school gate at 34mph concentrating on the road or someone driving at 29mph writing a text on their mobile phone ?. The former will trigger the speed camera, the latter will run into your kid without even realising they are there !!!
Where the influence of speed on motorcycling road deaths is concerned I think some of you will be utterly amazed at how this myth has been forever smashed when the latest statistics are released locally ;-)))
philthy
02-Oct-2006, 19:53
Nice to see that you guys are such paragons of virtue. Don't you ever exceed 60mph when you are out riding on country A roads?
You are absolutely right in saying that we should keep within the 30 mph limit in built up areas but to advocate going no faster than 60 seems incredible coming from motorcyclng enthusiasts.
We live and learn.
I drive for a living. No license no job, it's as simple as that. That and the things I've done and seen over the last 30 odd years of driving / riding do colour my judgement towards excessive speed.
That said, if I'm out on the bike and it's a sunny day I will use my common sense as to whether it's safe to up the pace a bit, but as all of my riding is done in North Wales where 1mph over will get you a ticket, I think it's pointless to go above 60 on a long straight, which is where any camera vans or traffic cops will be.
I'm quite happy for all the fast boys to play racers on the popular routes and keep the cops busy writing tickets so that I can go and play somewhere quieter and twistier.;)
How can there be no tolerance on a measurement ?
That was the point I was trying to make really. Who determines what 70mph is for instance ? What is the manufacturers tolerance on the speed cameras ? NOTHING is manufactured without a tolerance whether it be 0.0005% or 10% or expressed as something other than a percentage.
What is the manufacturers tolerance on a speedometer ? What effect does using tyres made by different manufacturers have opn speedometer readings?
Does anyone think that applying a strict 70mph limit has any true effect on road deaths and casualties when it usually goes hand in hand with a serious reduction in the police presence on our roads ? Would you rather have someone drive past your kids school gate at 34mph concentrating on the road or someone driving at 29mph writing a text on their mobile phone ?. The former will trigger the speed camera, the latter will run into your kid without even realising they are there !!!
Where the influence of speed on motorcycling road deaths is concerned I think some of you will be utterly amazed at how this myth has been forever smashed when the latest statistics are released locally ;-)))
The "tolerances" for the equipment used are probably available from the mannufacturer or maybe the operators manual, you could maybe try and get hold of the latter under FOI but don't expect them to give in easily!
The ACPO guidelines probabaly allow for the tolerance i.e the reading has to be well over the legal limit so even allowing for the tolerance of the equipment you are definately over the limit when nicked.
The no tolerance stasi have conveniently forgotten about this so there is a possibility that you can get done while still being under the limit and thats not taking operator error into acount. There are various individuals questioning the accuracy of various speed measuring devices used by talivan/scamera partnerships. A quick look round pepipoo has more info.
MCN had been digging about asking if equipment had been specifically tested on bikes, that seem to produce a mixed response form the various bodies questioned and a yes-no interlude.:lol:
Bike are difficult to "acquire" using some equipment............so never ride in a straight line :lol:
Ray.
I am convinced that the emplacement of so many speed cameras does not add to road safety one iota.
There is a valid argument for controlling speed in busy dangerous built up areas. This has always been the case and obviously always will be.
The business of the so called "Camera partnership" is to site cameras regardless of their efficacy in preventing deaths.
There is a move afoot to lower speed limits even further on our country roads.
These limits are already lower than they were in the 1950's when tyres and brakes were much less efficient.
What would add to road safety is more driver training and safer road surfaces.
psychlist
03-Oct-2006, 11:29
Car/Bike speedo's have to read within a band of -10% to +0% so, if your speedo says you're doing 70mph, then you could actually be doing anything from 70 down to 63mph. I had my bike's speedo "compared" with a guy I know who's speedo is "calibrated" for his work (ahem) and it was spot on at an indicated 70mph but I needed to be doing an indicated 33mph to be doing an actual 30! That was on well worn Diablo's. I did a simple check with him again when I had new tyres fitted and it was spot on all the way from 20mph up to 70. This is because a new tyre has a larger rolling circumference than a worn one and centrifugal force has a greater effect on a worn tyre than a new one (obvious when you think about it) so you travel further for each turn of the wheel/engine. If a motorcycle is heavily banked over round a fast corner then you'll be using a smaller diameter part of the tyre and the rolling circumference will be greatly reduced so you'll actually be going LOTS slower than your speedo may indicate!
From my limited experience it seems that stabilised radar/laser targetting devices in the hands of a trained operative are generally regarded as "absolute" measuring devices and it is up to the operator to use their judgement on the spot regarding the prevailing conditions to determine the actual course of events once a certain speed is indicated on the recording instrument, using the (very old, and some say out of touch with modern technology) ACPO guidelines as a yardstick, so you may get away with 79mph in some 70 limits and get done for much less in others.
Not that I know anything about the subject of course ;)
Paul James
03-Oct-2006, 14:01
Car/Bike speedo's have to read within a band of -10% to +0% so, if your speedo says you're doing 70mph, then you could actually be doing anything from 70 to 77 mph. I had my bike's speedo "compared" with a guy I know who's speedo is "calibrated" for his work (ahem) and it was spot on at an indicated 70mph but I needed to be doing an indicated 33mph to be doing an actual 30! That was on well worn Diablo's. I did a simple check with him again when I had new tyres fitted and it was spot on all the way from 20mph up to 70. This is because a new tyre has a larger rolling circumference than a worn one and centrifugal force has a greater effect on a worn tyre than a new one (obvious when you think about it) so you travel further for each turn of the wheel/engine. If a motorcycle is heavily banked over round a fast corner then you'll be using a smaller diameter part of the tyre and the rolling circumference will be greatly reduced so you'll actually be going LOTS slower than your speedo may indicate!
From my limited experience it seems that stabilised radar/laser targetting devices in the hands of a trained operative are generally regarded as "absolute" measuring devices and it is up to the operator to use their judgement on the spot regarding the prevailing conditions to determine the actual course of events once a certain speed is indicated on the recording instrument, using the (very old, and some say out of touch with modern technology) ACPO guidelines as a yardstick, so you may get away with 79mph in some 70 limits and get done for much less in others.
Not that I know anything about the subject of course ;)
Shouldn't that read "63 to 70 mph" Paul ?
My biggest concern is that there is no natinally agreed binding tolerance on the actual speed relative to the measuring equipment. It isn't just or reasonable for one police authority to apply "zero tolerance" speed enforcement while others apply the 10% + 2mph rule. The speed limits are national, so should the enforcement levels be, surely ?.
Rushjob
03-Oct-2006, 14:24
Question came up as a guy who does regular van deliveries to us recently got a ticket for doing 76 in a 70 zone, if the 10% plus 2mph was applied he shouldn't have been nicked.
Paul, you mention the guy driving a van getting done for 76 in a 70.....
If said van was anything bigger than, say, a Peugeot Partner or Transit Connect ( more than 2T gross ) and he was on a dual carriageway ( not motorway ) then his max speed in that vehicle would be 60mph so he would have been well over 10% + 2 ......... it's suprising how many drivers don't know the limits applied to the vehicles they drive
Shouldn't that read "63 to 70 mph" Paul ?
My biggest concern is that there is no natinally agreed binding tolerance on the actual speed relative to the measuring equipment. It isn't just or reasonable for one police authority to apply "zero tolerance" speed enforcement while others apply the 10% + 2mph rule. The speed limits are national, so should the enforcement levels be, surely ?.
Surely, the answer is the speed limit is the speed limit, and getting away with anything over that is a bonus?
At the end of the day, if it was written down that it's speed limit plus 10% plus 2mph, then the speed limit on a motorway or dual carriageway would in effect be 79mph...
psychlist
03-Oct-2006, 15:24
Shouldn't that read "63 to 70 mph" Paul ?
Yes, if the speedo tolerance is -10% to +0% then at an actual 70mph it would be reading about 77, when it reads 70 then you could be going as slow as 63 :rolleyes:
So, if the speedo is within tolerance, then you'd potentially have to be breaking the limit by only a few mph for it to be saying, say 80mph :rolleyes:
Paul James
03-Oct-2006, 19:36
Yes, if the speedo tolerance is -10% to +0% then at an actual 70mph it would be reading about 77, when it reads 70 then you could be going as slow as 63 :rolleyes:
So, if the speedo is within tolerance, then you'd potentially have to be breaking the limit by only a few mph for it to be saying, say 80mph :rolleyes:
Yup, what I thought you meant, makes sense for it to work that way I guess ;)
Still think there should be a national tolerance stated for all drivers (take your point about the vehicle types Rushjob).
Static speed cameras are biased in favour of lorries as if set to go off at the limit that applies to cars in 70 zones they can be way over their legal limit before tripping the camera. Surprised nobody has taken that one up at the European Court of Civil Liberties yet ;-)))
i think they can tell the difference between a car and a lorry
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