Military AI Works

On motorways where there are roadworks going on, there are usually variable speed cameras. My question is, is the speed taken between the 2 x cameras on the one pole or is it taken between the first pole to the second pole etc?
Also, when the speed limit is 50mph and vehicles are overtaking me at approx 60, are they getting fined, as there seem to be a lot of them.

The speed cameras will take your number plate and the time you passed them. Then when you pass the next one they should be able to work out what speed you have been doing on average. I'm not entirely sure how many you have to pass before you get a ticket, but it will probably be the same as Gatso cameras in this country in that they mostly are for show and aren't actually working, cos it costs too much money to run them.

Nick

I'll be one of those passing you by...

When it comes to enforcing the law, allowances have to be made for the fact that speedometers only have to be built with an accuracy of +/- 10%. Therefore, if you are travelling at 55mph, your speedometer could be reading anywhere between 49.5 mph and 60.5 mph within the legally allowable margin of error. So, if the speed limit is 50 mph, and you are clocked at 55 mph, you could claim that your speedometer was only reading as low as 49.5 mph. Therefore, due to the legally tolerated inaccuracy of your instruments, your speeding error was not your fault.

As a result of all this, you need to be doing at least 10% more than the speed limit for the police to be certain of a successful prosecution. However, that's not to say that your marginal speeding is any less likely to kill a child.

On the motorway in a 50 mph zone, you only need to slow down to 55mph by the time you pass the first camera. As soon as you pass the last camera you can immediately increase speed again, all this assuming that you are not currently being tailed by the police. They would probably prefer you to wait until the speed restriction "end" sign is reached. And if your route only takes you past one camera (if you're about to turn off, say) then you can ignore the camera presence altogether. But if the police are present, I don't suggest that you ignore their presence!

In practice, the police may have an even higher tolerance than 10%, but 10% is the minimum they can get you on. Any less, and you're within the legal margin of error of your instruments. The officers own discretion seems to play a part as well - I've seen many police just letting motorists go about their business at 80 mph on the motorways, without being pulled over - even though this is greater than 10% above the speed limit.

I guess Nick will know the actual Police position on all this.

A minor word of warning:

Not all speed restrictions are enforced by monitoring average speed. For example, on the motorway network near Birmingham, and possibly on the M25 as well, your speed is measured instantaneously. So if you are more than 10% above the current speed limit, you're nicked!

On average speed enforcement sectors, if you pass a camera at high speed it doesn't matter, provided you compensate by slowing down to lower than the speed limit in such a way that your average speed remains below the limit (+ the legal error margin) between this camera and the next one. But if instantaneous speed is measured, you do not get this chance to compensate by driving slower than the speed limit.

Luckily, the tell-tale signs of instantaneous speed measurement are familiar to most of us, as this is the same for speed cameras on most single-carriageway roads: Keep your eyes peeled for the sequence of little white calibration/scale marks on the road, generally after you pass underneath the overhead sign structures that bridge these sections of motorway.

... or you can go by Bus and let some other bugger worry about speed limits etc.

Being a Police Officer I would have to say, Stick to the speed limit and you won't have any problems.

Nick

"Better safe than sorry" is my motto when it comes to driving. There are way too many drivers out there with their minds on other things. I regularly witness all sorts of near-mishaps and other madness on the motorways in my part of the country. It's pretty scary how poor the standards can be - and all that in a country with a comparatively good safety record!

While I don't condone speeding, the facts remain about the need for tolerance margins. But I should probably check to make sure the value is still +/- 10%, as nowadays most speedo's are much more accurate, and a slimmer tolerance margin could certainly be legislated for if a need for this was identified. Something else related to these speedo error tolerance levels you may want also to consider: Driving at 55 mph "indicated road speed" in a 50 mph zone could still get you in trouble if your own speedo is reading even 1% too slow. The enforcement margins I refer to that allow one to marginally break the speed limit are there to make up for the potential inaccuracy of your own instruments.

I would certainly never count on the fact that I have seen police ignore motorists doing 80 mph (as there could be many reasons as to why), but it is reassuring to know that they are often more interested in specific cases of dangerous driving - rather than purely speeding offences.

nickblack423 wrote:Being a Police Officer I would have to say, Stick to the speed limit and you won't have any problems.

"nick, nick"

It's an old British joke but it has to be said under the circumstances

Just in case you'll spend some days in Germany. Despite having no limit on about 33% of our Autobahn there are limits on the remaining parts

Currently here is no such a thing of having two cams and time is taken (they call it "section control" here) but there are plans to change that (privacy concerns).

The tolerances:
Below 100kmph (ca. 60mph) they'll accept +3 kmph. Above 100kmph it's 3%. But usually fixed mounted cams will accept at least 5kmph (city limits) or 10kmph (elsewhere). It is very common to have police cam cars looking like civil cars. You may get away with up to +20kmph when on the Autobahn (except for in construction areas).

Thanks for the reply`s all.
I do stick to the speed limit that is being displayed, but I just wondered why cars are going passed me while I am at the max limit stated.
The police generally do 10% + 2 in the Hampshire area, so on a motorway they would not worry if you are doing 80mph.

Sprocky
I remember driving between Essen & Berlin, doing 80mph, with a police car overtaking me & another Mercedes flashing the police car to get out of the way.
Very strange, but we had a laugh about it.

The ones whizzing past you are probably not registered/insured. There is a scam going on where people have been registering their cars at 'ghost' addresses to avoid speeding/parking/miscellaneous offences. The address actually exists and any correspondance is forwarded, but when they get fines they just ignore them.

Is it true that you can't be fined by speed cameras that aren't yellow and don't have line markings on the road? I heard a rumour from someone about them being operated by the council and they tried to fine a friend of a friend of his but it wasn't legal.

Hmmm, sounds like chinese whispers...

If there are no markings on the road, you can't prove how far the car has travelled in the given time frame - and therefore you can't prove that it must have been breaking the law. Case closed!

Speed cameras that are up but have no road markings to judge the speed over distance are not active, they are merely installed as a warning and to try and slow down motorists.

Nick

We have a mobile camera in a van and a bloke on a motor bike with a camera on a tripod the only things we have is signs saying speed cameras.
No road markings

Gary

Garysb wrote:We have a mobile camera in a van and a bloke on a motor bike with a camera on a tripod the only things we have is signs saying speed cameras.
No road markings

Gary

Technically that is not a "camera", but mobile radar with an operator. The operator does the job of the "camera" by observing the offending vehicle. I guess that a policeman's word will be taken as being as definitive as photographic evidence from a legal perspective. Although I understand that you can be let off the hook if the radar detector's paperwork is not correct.

For unmanned cameras, it is also radar that detects the actual offence. But photos triggered at known time intervals are needed as evidence to prove the detection is not faulty, given that no officer of the law was present to confirm the misdemeanour.

Nevertheless Gary, you are right: it is true that we also need to be on the look out for these mobile cameras if we choose to dice with the speeding laws.

Usually mobile cams should be placed in dangerous places where accidents occur often (recommended here). While I see them most times right behind the city sign I rarely see them in 30kmph zones near a school or a kindergarden. That's why especially mobile cams are hated so much over here. It's purely to make money. They even had a TV show about it visiting a fair for this kind of equipment. Asking a salesman as an interested customer he told them: "Having a good place you will get back the money invested within days." Being a careful driver I only received one speeding ticket so far (in 17 years). I was driving a road where 50kmph and 70kmph speed limits were changing every few hundred meters. I somehow missed the latest 50kmph sign that day. Cruise control was set to 70kmph.

The recently installed cams don't even flash. Following cars will not be warned.

Caught doing 324 mph



Mark

Might have to fit that system to my car...