PLEASE NOTE, NO LAWS WERE BROKEN IN THE MAKING OF HIS THREAD!

I pass the same average speed camera every day on my way to work, at the junction of the M3 and M25. Recently some fairly serious roadworks have cropped up and they’re now scattered between j2 to j4a and being as I’m on the motorbike I have a lot of quiet thinking time.

Now, it’s dark at night now. As far as I can see there’s no way on this earth that the front facing cameras can track a front number plate* or take a pic when they’re dazzleid by car headlights, yes? I just can’t see how it’s possibe, photographically. I mean, these things don’t even have a flash do they?

I also think they’d struggle with rear plates at night. Even though rear plates are illuminated it’s still a tall order to take a pic, from an angle, up in the air, of a dimly lit bit of shiny plastic that’s, what, 30-40 yards away?

This is purely idle musing on my part. As I said, I pass these things every day, and I’m probably the slowest moving vehicle on the road, bar trucks, at bang on the speed limit.
What does the STW hive mind think. 🙂

* Not that I have one. 😉

Aren’t they lit by infrared and so not affected by the “visible” light from headlamps?

Dunno. You tell me! 🙂

Infrared illuminators apparently. http://www.speedcamerasuk.com/specs.htm

THEY know what you’re doing, PP. THEY know EVERYTHING about you.

Aye – that’ll be the IR lamps alongside

Having had a stack of them recently installed up the A9 I’ve become pretty familiar with what they look like.

Ahh OK. I didn’t know that.
Does that still work when dazzled by car lights then? I assume so.

they work with infrared – but although they are referred to as ‘cameras’ I don’t think they are taking pictures, really they are scanners and are just reading the numberplate ,its data they are collecting, they’re not taking a photograph of the car.

Similarly the ‘cameras’ in the congestion zone in london aren’t photographing everyones cars.

An ordinary speed camera would trigger if is reads that you are breaking the speed limit. Average speed cameras need to be reading registrations whether cars are speeding or not as its only the second (or third or forth) reading further up the road that would indicate if a driver is speeding, so the cameras would be taking hundreds of thousands of pictures of non-speeding cars all day for no reason

Ahh, I see. So if there’s no registration to read, they have absolutely no way of tracking a vehicle then?

They use infrared.

Infra red hmm? So they measure heat. I would imagine headlamps are a lot hotter than your number plate so effectively the heat coming off the lights would appear much brighter than the number plate thus surely the number plate wouldn’t be visible to the camera.

http://www.vysionics.com/product/specs

Each SPECS camera continuously captures images of vehicles as they pass through the field of view. The number plates are read using ANPR and, when the same vehicle is recorded by any other camera connected to the system, the average speed of the vehicle is calculated over the known baseline distance. If this speed exceeds the Police threshold, an offence record is created and violation images and data are logged.

Cameras can be installed in front or rear-facing orientation and violations can be recorded between multiple locations and multiple lanes within the system.

Each camera unit has an infrared ANPR camera and an infrared illuminator, which enables number plates to be read, regardless of light or weather conditions. A colour day/night overview camera is also included, which enables overview images to be captured in daylight and in most street lit environments. Infrared floodlights can be installed where street lighting is not available and visible lighting is undesirable, making overview image capture possible in complete darkness.

That pretty much goes without saying?

Infra red hmm? So they measure heat.

nope they just use 940 nm led emitters, number plates are retroreflective so the “light” is reflected straight back to the camera

PeterPoddy

Ah, so you’re the one….

Thanks

I’m sure there was a case of a biker repeatedly tripping a front-facing camera, and although there was no plate, he did it enough times, they decided to make the effort to trace him by the appearance of his leathers and helmet. Can’t find a reference though.

And I’ve never tripped front-facing camera on my bike. Ever. Honest. Scouts honour.

Ben, yeah. A camera will take a pic of an object travelling over a preset speed. Whatever that object is. Enough pics of the front of the same bike and someone will get annoyed and come looking for you.
But, as I understand it, these average speed cameras have no point of reference without a number plate, so without that you don’t even exist to them……

sorry for hijack out of rush hour how do they cope down in englandshire with them anyway ?

was on the a9 (south perth to dunblane) for the first time at the weekend with them – does the folk not watching the road but watching the speedo instead mentality go away as folk get accustom to them?

saw drifters / saw lane changing without looking , saw folk slamming brakes hard on as they hadnt noticed cars traveling slower coming up infront.

ive traveled that road quite extensively and nver seen so many near misses….

a9 north to inverness – yep crazy overtakes ahoy… something average speed cameras wont prevent.

Some of the new A9 ones are pointing backwards – so they would in theory get your rear plate 👿

Didn’t top gear prove that a black TVR doing 137mph could get through a normal speed camera and not be in the picture? obviously not advised on an average speed zone but still…

As far as I can see there’s no way on this earth that the front facing cameras can track a front number plate* or take a pic when they’re dazzleid by car headlights, yes?

You honestly think they’d create, buy and deploy these things if they didn’t actually work?

Btw ‘infra-red’ covers a fairly wide range of the spectrum, so they can pick a wavelength for their floodlamps and filter the scanner based on that. Seems to work.

this one ?

http://www.northumbria.police.uk/releasedetails.asp?id=96999

http://www.mirror.co.uk/news/uk-news/reckless-foolish-biker-caught-doing-3863256

“You honestly think they’d create, buy and deploy these things if they didn’t actually work?”

The first gens didnt actually work all that well 😉

Didn’t top gear prove that a black TVR doing 137mph could get through a normal speed camera and not be in the picture? obviously not advised on an average speed zone but still…

Pretty sure that was 173

Yeah, it was above 170mph before the TVR went so fast that it wasn’t in the second picture for the ‘double flash’ speed camera.

trail_rat – Member

The first gens didnt actually work all that well

Always heard a rumour that the first gen avg speed cameras couldn’t keep track of you if you changed lanes! Was never sure how true it was.

Does anyone know anyone who’s been done by one of these?

I always see people pushing the limits, going past me easily at 60 whilst I am bang on 50.

I even had a lorry flash me once trying to get me out of the way. I was doing bang on 50 according to my speedo (which I appreciate might not be accurate)

Also there have been times where my concentration has laxed and I look down to see 55+ – but no fine yet.

Always heard a rumour that the first gen avg speed cameras couldn’t keep track of you if you changed lanes! Was never sure how true it was.

It was true a few years ago. A friend worked at MIRA where they are tested. It was because the 2 cameras had to be linked by a wire to send the information so the speed could be calulated. You could only link 2 cameras together so changing lanes would work. Whether this is still true I have no idea.

yep I got done in a set on the M5 at 2 in the morning, gateway sign was 50, so set the cruise to 48 and then it dropped for a short section to 40 (without a gateway) before going back to 50, got nabbed for the 40 bit (the 40 gateway went up after I complained and challenged it but sill got to go on a speed course, which was actually pretty good)

You honestly think they’d create, buy and deploy these things if they didn’t actually work?

Don’t talk down to me please, I’m not an idiot. I asked a simple question. I’m sure there’s lots I know that you don’t.

Always heard a rumour that the first gen avg speed cameras couldn’t keep track of you if you changed lanes! Was never sure how true it was.

It was true a few years ago

It was, yes. MCN did some quite in depth investigation into it at the time. It was kept quiet for a while, understandably, but it’s long fixed now

There’s a long section of 50mph limit on the M1 near me which is enforced by average speed cameras. They have set up lights to illuminate a strip of road at each camera installation – not sure whether this helps the cameras to work or it highlights the fact that they are there.

Bloody bright those lights are as well.

The cameras work in daylight, dark, rain and fog and can read three lanes of dense traffic. It used to be said that you could outsmart them by exiting the controlled stretch in a different lane to the one in which you entered but I wouldn’t want to risk testing that theory.

Does anyone know anyone who’s been done by one of these?

I always see people pushing the limits, going past me easily at 60 whilst I am bang on 50.

practically everyone i know has been done at some point! 😆

but i’m always amazed by the number of people who seem to be merrily sailing through at about 55.

see also: anywhere within the m25 at about 4 in the morning. i quite often drive west from central london at stupid o clock and it just seems like taxis must operate to different speed limits than me…

bare in mind if your all using your using your speedo to judge your speed your under the limit anyway.

8,000 people caught by em in 7 months on the M1 in Derbyshire/South Yorks roadworks, so I guess they work reasonable well.

Infra red hmm? So they measure heat. I would imagine headlamps are a lot hotter than your number plate so effectively the heat coming off the lights would appear much brighter than the number plate thus surely the number plate wouldn’t be visible to the camera.

You can point a camera* direclty into the sun and take a pic that’s exposed correctly, it is doable you just pick a shutter speed, ISO and appeture that expose the bit you want to see.

*not adviseable, a film camera pointed at the sun and set to expose the foreground will happily melt the film, I’ve no idea what it does to a digital sensor.

Always heard a rumour that the first gen avg speed cameras couldn’t keep track of you if you changed lanes! Was never sure how true it was.

It was true a few years ago. A friend worked at MIRA where they are tested. It was because the 2 cameras had to be linked by a wire to send the information so the speed could be calulated. You could only link 2 cameras together so changing lanes would work. Whether this is still true I have no idea. [/quote]

I seem to recall reading it was a legal thing, the system could cope but the original legislation stated that cameras had to be paired so they couldn’t use the information from the whole set of cameras to convict you, they had to designate pairs and just use photos from each pair.

There is a popular misconception that the Home Office has approved the SPECS system for single-lane use only. According to this theory, a motorist can therefore switch lanes between cameras and claim non-approval to avoid prosecution for speeding.[5] However the marketing director of the manufacturer, Speedcheck Services Ltd, has stated that this theory is “categorically untrue”:[6]
“ Until recently, the only HOTA available applied to cars maintaining their lanes. However a new test schedule was carried out last year, which means that average speed checking can be applied even where cars change lanes. ”

The cameras are often painted yellow and have been given the nickname “yellow vultures”.[7]

Im amazed these havent taken off!

Or have they but only in Taxi world?

Its not infra red as in thermal its near infra red. So almost visible but not. The camera isn’t blinded by headlights because the CCD (sensor array) isn’t tuned to light we see. I’d be surprised if there wasn’t a threshold light level that normal visible light CCD doesn’t take over so as not to dazzle the n-ir one.