Cranfield Posted April 14, 2007 Report Share Posted April 14, 2007 I was up in the Coventry area today, investigating some potential pigeon shooting opportunities (I also took time to go to The Otterhound Club Single Breed Open Show at Baginton). On the M25 and M1 there were sections of roadworks that had the "average speed cameras". You pass through one at the beginning of the roadworks and one at the end. Which of these happens ? Camera No 1 takes a record of your speed in, then camera No 2 records your speed out, add the two together and then divide by two, to get the average speed. Or; Camera No 1 records when you enter the system and camera No 2 records when you leave, it then calculates your average speed through the restricted area. Although you are instructed not to change lanes, does changing lane mess the cameras up ? Are they actually working ? I observed the speed limits carefully, but quite a few people were zooming along. There were so many restricted areas, that with 3 points an offence, you could lose your licence between Watford Gap and Corley Services. Quote Link to comment Share on other sites More sharing options...
Mungler Posted April 14, 2007 Report Share Posted April 14, 2007 It's time over distance for average speed. Changing lanes doesn't matter, the OCR works very well these days. Underhanded, that's what it is. Quote Link to comment Share on other sites More sharing options...
jacob w h Posted April 14, 2007 Report Share Posted April 14, 2007 they mentioned it on top gear they said go through the first one pull over for 10 minutes then do a 120 the rest of the way home Quote Link to comment Share on other sites More sharing options...
Cranfield Posted April 14, 2007 Author Report Share Posted April 14, 2007 So a few of the other drivers must have watched Top Gear, but just forgot the bit about pulling over. Quote Link to comment Share on other sites More sharing options...
pin Posted April 14, 2007 Report Share Posted April 14, 2007 Motorbikes are immune, the cameras are forward facing only and with only a rear plate... Some places have a restricted area in which it is possible to either start already inside the restriction and only pass the exit camera, or enter the restriction but leave the road before the end camera. My guess is this is what you were seeing.. That or forged plates, altered plates, plates with anti-camera reflective coatings etc Quote Link to comment Share on other sites More sharing options...
blackthorn Posted April 14, 2007 Report Share Posted April 14, 2007 dirty plates work well, so did we pop in for tea at coventry Quote Link to comment Share on other sites More sharing options...
pin Posted April 14, 2007 Report Share Posted April 14, 2007 I tried that, but if you ever get a cop car directly behind you they will suss immediately, the ANPR system won't beep meaning it can't register your plate and they will pull you over and could fine you (I got off with a warning)... Quote Link to comment Share on other sites More sharing options...
blackthorn Posted April 14, 2007 Report Share Posted April 14, 2007 I tried that, but if you ever get a cop car directly behind you they will suss immediately, the ANPR system won't beep meaning it can't register your plate and they will pull you over and could fine you (I got off with a warning)... (I got off with a warning)... not long been of road, sorry officer, or down that line. better still watch your speed and stop taking chances Quote Link to comment Share on other sites More sharing options...
dunganick Posted April 14, 2007 Report Share Posted April 14, 2007 can they work as standard speed camera's on the junction between the m20 and m26 (london bound) there is a slip road off the m26 imediatly after you enter it, however there is 1 average speed camera before this slip road, my question is, if i do say 50 through this 40 (talking theoretically here as of course i dont condone speeding) would it do me for being blatently over the limit at the time. Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 14, 2007 Report Share Posted April 14, 2007 can they work as standard speed camera's on the junction between the m20 and m26 (london bound) there is a slip road off the m26 imediatly after you enter it, however there is 1 average speed camera before this slip road, my question is, if i do say 50 through this 40 (talking theoretically here as of course i dont condone speeding) would it do me for being blatently over the limit at the time. Nope, in theory not! Speed camera's normally work on the simple fomula distance/time = speed. So they use lines to measure the time you take to pass between them and if its quicker than a certain time, snap goes the camera. Each average speed camera only has one "line" so in order for it to catch you they need 2 camera's (to provide a known distance with 2 lines to time you over) The other method camera's work on is the doppler effect (which I cant remember exactly what it is, forgot that bit of as physics) however this would require a lazer of some description and average speed camera's dont have those! Quote Link to comment Share on other sites More sharing options...
blackthorn Posted April 14, 2007 Report Share Posted April 14, 2007 can they work as standard speed camera's on the junction between the m20 and m26 (london bound) there is a slip road off the m26 imediatly after you enter it, however there is 1 average speed camera before this slip road, my question is, if i do say 50 through this 40 (talking theoretically here as of course i dont condone speeding) would it do me for being blatently over the limit at the time. kid you have 6 points to play with over the next 2 years, a lot to lose , and all that **** to go through again Quote Link to comment Share on other sites More sharing options...
Northerner Posted April 14, 2007 Report Share Posted April 14, 2007 It was mentioned on top gear, during the news section, that changing lanes does effect the reading thus doing so is not advised just googled it and found THIS Quote Link to comment Share on other sites More sharing options...
dunganick Posted April 14, 2007 Report Share Posted April 14, 2007 can they work as standard speed camera's on the junction between the m20 and m26 (london bound) there is a slip road off the m26 imediatly after you enter it, however there is 1 average speed camera before this slip road, my question is, if i do say 50 through this 40 (talking theoretically here as of course i dont condone speeding) would it do me for being blatently over the limit at the time. kid you have 6 points to play with over the next 2 years, a lot to lose , and all that **** to go through again dont worry, was talking theoretically, just like to understand what im trying not to get caught by. Quote Link to comment Share on other sites More sharing options...
pin Posted April 14, 2007 Report Share Posted April 14, 2007 Nope, in theory not! Speed camera's normally work on the simple fomula distance/time = speed. So they use lines to measure the time you take to pass between them and if its quicker than a certain time, snap goes the camera. Each average speed camera only has one "line" so in order for it to catch you they need 2 camera's (to provide a known distance with 2 lines to time you over) The other method camera's work on is the doppler effect (which I cant remember exactly what it is, forgot that bit of as physics) however this would require a lazer of some description and average speed camera's dont have those! Correct. SPECS doesn't use RADAR, it is a live DV feed to computers running OCR (optical character recognition) software. They clock your plate and the time that it was clocked. The far end clocks the plate on the way out, and since the distance between the cameras is known, they know your average speed. The GATSO/TRUVELO (and other) types rely on RADAR to clock you. Doppler effect, the phase shift of a known frequency signal when reflected from an object. If it isn't moving it won't shift much, the more it is moving the more it shifts. These rely on a calibrated marking on the road and take two pictures when triggered. The distance you have moved in the known time between photos will reveal your speed. Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 14, 2007 Report Share Posted April 14, 2007 Nope, in theory not! Speed camera's normally work on the simple fomula distance/time = speed. So they use lines to measure the time you take to pass between them and if its quicker than a certain time, snap goes the camera. Each average speed camera only has one "line" so in order for it to catch you they need 2 camera's (to provide a known distance with 2 lines to time you over) The other method camera's work on is the doppler effect (which I cant remember exactly what it is, forgot that bit of as physics) however this would require a lazer of some description and average speed camera's dont have those! Correct. SPECS doesn't use RADAR, it is a live DV feed to computers running OCR (optical character recognition) software. They clock your plate and the time that it was clocked. The far end clocks the plate on the way out, and since the distance between the cameras is known, they know your average speed. The GATSO/TRUVELO (and other) types rely on RADAR to clock you. Doppler effect, the phase shift of a known frequency signal when reflected from an object. If it isn't moving it won't shift much, the more it is moving the more it shifts. These rely on a calibrated marking on the road and take two pictures when triggered. The distance you have moved in the known time between photos will reveal your speed. Do I get an A* sir? Thats why some of the "smarter" vandals are learning its far more effective to remove the lines than damage the lens as 90% of time camera's are on busier roads so they cant close the road off to repaint the lines Quote Link to comment Share on other sites More sharing options...
pin Posted April 14, 2007 Report Share Posted April 14, 2007 I hear its not even necessary to damage the lines, simply painting them will do. Mind, I heard that from a bloke down the pub Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 15, 2007 Report Share Posted April 15, 2007 I hear its not even necessary to damage the lines, simply painting them will do. Mind, I heard that from a bloke down the pub Yeah, I can confirm that painting works (better with some thick tar like stuff) as thats what they do around this way. It makes a change for vandals to be almost supported by the public, does show how hated the camera's are though! Quote Link to comment Share on other sites More sharing options...
Dave-G Posted April 15, 2007 Report Share Posted April 15, 2007 Apparently it's not quite so simple as changing lanes between camera's. Let's say for this post that there are 6 camera's in a specs monitoring zone. The first and third could be the start and finish of one of the data points, second and fourth, then fifth and sixth just to catch the dodgers out. Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 15, 2007 Report Share Posted April 15, 2007 Apparently it's not quite so simple as changing lanes between camera's. Let's say for this post that there are 6 camera's in a specs monitoring zone. The first and third could be the start and finish of one of the data points, second and fourth, then fifth and sixth just to catch the dodgers out. Changing lanes doesn't work because the camera's have sificently wide scope to mointor both lanes at the same time. Althou in THEORY if you tailgated someone big time (which is stupid and a big cause of motorway accidents so DON'T) your licence plate would be obscured from the camera and vola no speeding ticket. Personally, I would rather see the camera deploy a .50 cal machine gun on any tailgater as they are stupid morons who cause accidents unnesecarrily. Quote Link to comment Share on other sites More sharing options...
dusk2dawn Posted April 15, 2007 Report Share Posted April 15, 2007 dirty plates work well, so did we pop in for tea at coventry Dirty plates, obscured or wrongly spaced lettering will all earn you a fixed penalty and 3 points in the post if the camera identifies the vehicle, is it really worth it? The average distance cameras are always working, they do not require any attention as do Gatso cams. The cameras that annoy me are the variable speed jobbies on the M25 everyone blasts up to them at 90 mph then brake at the last minute to go through at the set speed. Its not until renewal time comes round that you will realise that not only do you get penalised for speeding but the insurance company "fine "you as well for points on the licence, taint fair is it? D2D Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 15, 2007 Report Share Posted April 15, 2007 dirty plates work well, so did we pop in for tea at coventry Dirty plates, obscured or wrongly spaced lettering will all earn you a fixed penalty and 3 points in the post if the camera identifies the vehicle, is it really worth it? The average distance cameras are always working, they do not require any attention as do Gatso cams. The cameras that annoy me are the variable speed jobbies on the M25 everyone blasts up to them at 90 mph then brake at the last minute to go through at the set speed. Its not until renewal time comes round that you will realise that not only do you get penalised for speeding but the insurance company "fine "you as well for points on the licence, taint fair is it? D2D Yep, espically when you are under the age of 25 and your insurance is already £1,300!!! Dont forget, for the first 2 years its only 6 points and then bye bye licence! Quote Link to comment Share on other sites More sharing options...
Pedro Posted April 15, 2007 Report Share Posted April 15, 2007 Just a side note for any of you that ride/drive in Essex - their bike squad is back in action. I got pulled yesterday on the Blade by a copper on a Pan European. To be fair, the guy was very good and gave me a verbal warning, (well before he asked for ID BTW). That's what's wrong with these bloomin cameras and things - no discretion P. Quote Link to comment Share on other sites More sharing options...
death from below Posted April 15, 2007 Report Share Posted April 15, 2007 How about a novel idea.....just don't speed.........sounds a bit hollier than though....I never do any more than 80 and have a clean licence....some of the plebs I see hammering past me at times(on 2 and 4 wheels) deserve a spate inside never mind some points......all these argument s about "I'm a great driver ......drive better at high speeds etc is just bull.....I've had my days of tonking the speed limit(used to own an R1) but I get bored with people whinging about getting done for trying to recreate back to the future.....have a thought for others before you hammer it. DFB Quote Link to comment Share on other sites More sharing options...
Browning GTS Posted April 15, 2007 Report Share Posted April 15, 2007 I think the best way to beat the speed gun is not to speed simple realy ( he says with 3 points) Quote Link to comment Share on other sites More sharing options...
naddan28 Posted April 15, 2007 Report Share Posted April 15, 2007 I have a clean licence and never breach 80-90mph and only drive at those sorts of paces on the motorway. What cracks me up is the people driving at night around the country lanes who aint got a clue with the roads. A lot of young lads seem to be parking in the hedgerows and middle aged people overtake me (in my Ford Ka) then wobble round the corners. Their is nothing more annoying to a tailgating **** than not being able to overtake a Ka when they have a mondeo etc, Ka's just carry speed well round corners and I know the lanes, so I know when & where its appropriate to corner at 50 and when you need to go at 25! Quote Link to comment Share on other sites More sharing options...
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