Observation
Last week the speed cameras on the M4 managed bit by Bristol flashed on the eastbound carriageway for someone possibly over the limit.
Question
I thought all speed cameras had to be painted yellow. The ones on the gantry are not…
Can anyone shed any light? (And not two flashes!)
Paul
They only need to be painted yellow if there are no camera signs to indicate that you are in a speed detection zone. If there are signs, either on the gantry or elsewhere, then the cameras can be hidden as you’ve already been warned by the signs.
I’ve also noticed they seem a bit flash happy when a limit’s in force. Been down the west a few times over past couple of weeks & on one journey down saw one go off on three occasions as I approached from the opposite direction.
Lee1976:
They only need to be painted yellow if there are no camera signs to indicate that you are in a speed detection zone. If there are signs, either on the gantry or elsewhere, then the cameras can be hidden as you’ve already been warned by the signs.
I don’t think that’s quite correct. My understanding is that cameras operating under the hypothecation rules of the “Safety Camera Partnerships” (where money from fines is “ploughed back” into road safety works etc) have to be hi-vis, but others do not. Unless this has changed recently?
Not rocket science is it? Slow down and they don’t flash! 
Roymondo:
Lee1976:
They only need to be painted yellow if there are no camera signs to indicate that you are in a speed detection zone. If there are signs, either on the gantry or elsewhere, then the cameras can be hidden as you’ve already been warned by the signs.I don’t think that’s quite correct. My understanding is that cameras operating under the hypothecation rules of the “Safety Camera Partnerships” (where money from fines is “ploughed back” into road safety works etc) have to be hi-vis, but others do not. Unless this has changed recently?
No legal requirement for the camera’s to be visible (yellow) nor is there any requirement for the speed camera signs.
Just because the camera wasn’t painted yellow or there was no signs, doesn’t mean you can’t be done for speeding
I’m not saying it’s a legal requirement - but it is (or certainly was at any rate) one of the rules under which the Safety Camera Partnerships operate(d). Not that a breach of said rules would help you contest a case in court (although it might get a FP ticket rescinded).
If a speed camera does not flash twice, then it cannot measure your speed.
This of course means that if you refute the fine when it comes through the post, it will probably be dropped, even if there is a SINGLE nice shiny pic of your vehicle enclosed as a “snapshot”.
Gantry cameras have been known to flash at open road in the middle of the night, so there is always going to be sufficient doubt there that should you challenge any “proof” that you were speeding, the whole thing should get dropped.
TWO pictures taken against the measuring ruler that are the white painted notches on the road surface will provide proper proof of what speed was being done. It was always traditional that you’d be “given 10%”, so if a speed camera clocked you at 53mph in a 50 zone, it would not be pursued. Most cameras are set way above the 10% line anyways, so that when they actually double-snap someone, they’ve got the punter being photographed bang to rights, because their speed must be taking the ■■■■ at that time.
Eg. if you get snapped at 63mph in a 50 zone, with the camera set to 60mph before it even goes off - you’re not going to get away with it unless you can challenge on the “single snap” doubt…
The one I always found strange was the “floating speed limits” on motorway management systems where you’ll get overheads flashing 50, then 40 to go into some single lane roadwork stretch etc. You’d think the cameras would also be brought down to trigger at say, 10mph above the new temp speed limit - but this doesn’t seem to happen, looking at how other traffic speeds past you when YOU have slowed to to the 40mph, and others are still doing 50-70mph still…
Unless of course it’s one of the Truvelo cameras that only flash once…
Roymondo:
Unless of course it’s one of the Truvelo cameras that only flash once…
Correct as the secondary check is done via the induction loop in the road
These cameras are not under the same rules as the Safety Camera partnership so they don’t need to be Yellow. Also very soon they will be operating on the Hard Shoulder when it is closed and Red X’s are set as 90% of the public don’t seem to relate RED and an X to danger,weird. I understand from a colleague that way that people use the hard shoulder when it says “Hard shoulders for emergency only” and don’t use it when it says “Congestion use hard shoulder” nowt as queer as folk.
What I don’t get is anywhere on the network when a lane closure is set why everyone feels the need to drive right up to the cones (if there are cones there) and literally follow them out with no consideration as to whether there will be a space alongside them when they have less than a few hundred metres to move over or whether there may be a person, animal or tyre led there.
One thing I hear all the time when I ask people why they don’t move over when they see lane closure signs they say they wait until they see something and then move as half the time there isn’t anything there. That’s really reassuring to hear when I’m stood in a live lane trying to help someone. Something else to bear in mind is a lane closure can be set when debris or a broken down car is seen in that lane BUT if that car moves over onto the hard shoulder or the debris is hitand leaves that lane, the signs won’t be cancelled until the Police or TO’s arrive, just because you can’t or don’t see it, it doesn’t mean nothing was there. At the end of the day, if you see lane closures set, please just pull over just in case, it cost’s nothing and could get you out of doo doo.
Tell you what Big Jase I can’t find fault in anything you wrote there. All gained from personal experience bearing in mind the job you do, so you more than many know the facts behind what you wrote.
I will however bring up the last paragraph re folk ignoring overhead signs. Once again I cannot dispute what you say, but I would say that this is a problem that’s almost 100% down to the operators of those signs. The sad but simple truth is that nobody believes a single thing written on them. It’s unfortunate but after years of bombardment with factually incorrect or totally erroneous signs people tend to ignore them.
I know it’s not your area but Scotland ffs! Do the numpties who operate these signs just come up with random stuff to put on them? You may as well get Toby stoned and drunk and let him loose with the keyboard 'cos I guarantee it’d make more sense than the rubbish they put up. On the M74 just outside Glasgow recently I was informed that the A1 was blocked at the A47 junction! Really helpful that.
the maoster:
On the M74 just outside Glasgow recently I was informed that the A1 was blocked at the A47 junction! Really helpful that.
I’ve been southwardbound on the A1M in our beloved North Yorkshire (all bow) and have been told very helpfully that the M11 is blocked
My favourite one though, is the one that says “belt up in the back”. Whenever I see that one, I look round and say “yes, forkin belt up!” 
It always reminds me of the time when me, big bro and big sis were arguing in the back of the car on holiday sometime in the early 70’s. In exasperation, my mum rounded on my dad and said “Peter, will you talk to your children!!” Dear old Dad, bless him, turned round and said “Hello children”.
I learned a long time ago to ignore the ones that advised of “obstruction in carriageway”, “lane closure ahead”, “accident” or that catch-all “incident - slow down” and essentially just treat them as a “be extra vigilant” warning until I could actually engage the problem with my Mk1 human eyeballs. The reason being that these messages are input by human operators who may or may not have a handle on what is actually going on, may or may not have updated them since the original problem was reported and may or may not remember to cancel them when it has cleared. “Congestion after Jct” or “Queue ahead” I will normally pay attention to though, as these are generally activated by automated systems that do routinely update themselves and do detect genuine queues and congestion.
I see exactly what you are saying but rest assured they are not set for fun, why would anyone do that to discredit them?
I’ll give an example, I’ve just come from a guy who hit debris in the road and blew a tyre out. He said he hit it in lane 2.We HAD to set signs to warn others of a potential deadly peice of debris in the road, imagine a motorcyclist hitting it. As it was, when he hit the debris and unbeknown to him, he’d fired it off to the verge so nothing in the road but no one knew that at that time. Now if we didn’t put signs up, we’d be in the situation of you hitting it and blowing out an airline, a £300 call out fee and a missed drop off but worse still being stuck in lane 2 and unable to move. We’d then close the lanes and thousands of truckers would be slagging us off for not moving the truck. Your company would then be seeking damages from the HA for failing to tell you about debris that we knew about.
If that seems pie in the sky, I’m sure you’re all reading about the Taunton fireworks crash were the HA are being accused of not telling people about the fog and that the CCTV was faulty. It shouldn’t be our job to tell you you can’t see ahead of you but we do.
I’ve had a report of an rtc literally 1 mile ahead of me, 4 cars, lane 4, I got around the bend, nothing. Who made that call? Was it a hoax? Luckily the signs were only on saying Accident for a few seconds but you can see why it happens.
I would love nothing more than to have some real drivers visit my Rcc to see how it works and pass that on to all of you but I doubt that will ever happen and we will still be criticised anyway.
Big Jase:
I would love nothing more than to have some real drivers visit my Rcc to see how it works and pass that on to all of you but I doubt that will ever happen and we will still be criticised anyway.
Coffeeholic did that back in 2007 and posted this topic about his visit.
I worked in such a control room myself for several years, Jase. Back in the day when it was all done by Police, without the benefit of automatic detection systems or even CCTV cameras to monitor traffic/incidents.
It’s moved on a lot since then I can tell ya.
The one thing I immediately thought above was replying that a lot has changed since 2007 but once reading it, nothing has changed and it us exactly the same except for the fact we are not meant to do 50. As much as it may help in seeing stuff, it makes you at 56 have to cause congestion in lane 2, something which we are here to prevent.
trubster:
Roymondo:
Unless of course it’s one of the Truvelo cameras that only flash once…Correct as the secondary check is done via the induction loop in the road
Are there not two wires across the road that trigger the camera if they are passed “too quickly”?
This would mean passing the loops is the primary check. The camera goes off because it’s been told to as a secondary function by the triggered induction loops…
A single loop could measure speed, albeit less accurately, by timing front and rear axles pressing down. This would lead to the obvious flaw though of cars like Fiat 126’s getting flashed doing 28 in a 30 zone, with brick hiab lorries steaming through, and not triggering the device…
All obsolete late-90’s kit though. They’d be the camera boxes with the graffiti on them most likely.
Didn’t Truvelo cameras “always run out of film” as well btw? 
Wires across the road? How quaint! Yes, we used to use those back in the day for speed checks, before the widespread introduction of hand-held radar. Similar kit is still used for unmanned vehicle counting/monitoring (although I think they are usually pneumatic tubes rather than the co-ax cables we used). Wires/tubes pegged down with steel spikes hammered into the road surface.
No, the Truvelo cameras I am on about use multiple sets of piezo sensors buried in the road surface. These generate a voltage in response to the pressure of a vehicle driving over, with each set giving an independent speed reading. If they all agree on the speed (and it’s over the limit, of course!) a single photo is taken a set time afterwards (I think it’s half a second). There is a line painted on the road and, if the vehicle has passed the line by the time the photo is taken, it confirms it was exceeding the limit. Still current, and still used all over the country. This is what they look like:
