Safe Speed Forums

In MCN today

"The Highways Agency has confirmed reports stating that digital speed cameras are set to replace film-based cameras on the variable speed limit section of the M25 past Heathrow from February 15.

A spokeswoman for the Agency told MCN the new cameras will be capable of reading rear number plates, and that road markings will be upgraded to allow more accurate speed readings to be taken.

The speed at which the cameras are triggered is also set to fall from around 90mph at present, to a 10% +2 mph above the 70 limit, when variable limits are not in operation."

Considering the planned rollout of variable speed limits across the motorway network nationwide, is this a way of speed enforcing all motorways by stealth?

Surely it's now time to raise the motorway limit to 80...

(apologies to SafeSpeed member "orange" who posted this on another forum)

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

Yes, hmm. I am familiar with the stretch, and I fear they may compound the unintended consequences of camera use through these actions. Its a decent stretch of road, albeit heavily used, and I was not aware that it was sufficiently dangerous to warrant these measures.

Lets break it down: Variable speed limits on motorways are not particularly safety driven. The main boon from being able to slow traffic on a motorway is the ability to prevent traffic filling the back of a shockwave-type jam quicker than the front is cleared. If they are adhered to by faster drivers they can even prevent these shockwaves from forming in the first place, by preventing the over-braking that propogates rearwards until a stationary iteration occurs.

Many drivers presumably did not conform to these limits, sufficiently to prevent jams, whilst they were advisory, and so a system was put in place to make them mandatory: red circles of leds around the numbers, and presumably a traffic order to match. An extra stick was included in the form of cameras; clearly with the 'unintended but highly welcome' side-effect of revenue generation.

These days the only time I see this stretch of road heavily congested is when it reaches capacity, evidenced by the jams easing after a junction, rather than between junctions, which would be indicative of a shockwave. Thus the variable limits are achieving their optimum benefit. I fail to see how penalising drivers who make progress on a well engineered, safe stretch of highway in light traffic conditions and fair weather is going to make this already safe stretch of road any safer.

Its a cash-cow, if they're not getting rich enough quick enough they just have to flick a switch and the limits lower and the money rolls in.

EDIT: On reflection, this measure is actually likely to increase congestion on the road, as the speeding up and then braking that will inevitably occur between gantries is far more condusive to shockwave-type jams than smooth driving!

The fact that the J12 M3 trial has been going on for more than two years now would also help in creating jams in that area as you cannot do more than 30mph approximately on the M3 in rush hour at the moment.

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Prepare to be Judged

I have in the lasts few months travelled anticlockwise at around 02:00 to find the signs on the approach to the M4 junction showing 50 despite there only being a dozen or so vehicles visible front and behind on both carriage ways. Is this just a revenue earning scam?

Worse still on one occasion (very early morning too) a few years ago one randomly went from off to 40 when I was only a few feet from it. I managed to reduce my speed to under 40 but have often wondered whether I would have received a ticket if I had not stood on the brakes. Is there a grace period after the limit is changed during which you won't get a ticket?

I was also under the impression that you should not see a 40 unless there was a reduction posted on the sign before.

There's a similar story in the Daily Wail. No link unfortunately.

Cameras target m-way drivers

Thousands more motorway drivers will be hit with speeding fines in a new speed camera blitz. They will be caught if they creep over variable speed limits, which are set according to the levels of traffic.

Experts believe that by reducing the speed limit when motorways are busy they can prevent the tailbacks that are created when drivers brake sharply as they approach slower moving vehicles

Variable speeds are already used on the M25 west of London and the M42 on the edge of Birmingham. Cameras enforce the limits.

From February 15, all speed cameras will become digital in the variable speed limit section of the M25 from junctions 10 to 16-the A3 junction to the M40, the Daily Mail can reveal.

Until now, variable speed limit cameras on the M25 have used film, which limits the number of pictures that can be taken before the film has to be changed. However digital cameras can capture an almost indefinite number of images.

The "speed threshold" - the amount drivers can stray above the limit without getting a ticket is also being lowered. Police forces say it will be set at79mph.

Variable speed limits are also expected to come into force on the M6 between Birmingham and Manchester and parts of the M1

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Anyone who tells you that nothing is impossible has never bathed in a saucer of water.

The 'shockwave' tailbacks are absolutely not caused by speed, they are in fact caused by following too closely, which means that any braking is amplified as it travels rearwards along the carriageway and, if traffic conditions are heavy and bunched enough, eventually causes a complete halt. Traffic then joins the back of this 'plug' at a greater rate than it is released from the front, and it will not clear as long as those conditions persist.

Once a 'plug' has formed, slowing traffic on the approach can allow the plug time to clear, but slowing it down before a jam has formed has no prophylactic effect whatsoever, since the phenomenon can occur wherever tailgating is taking place, regardless of speeds. Indeed, my observation is that at artificially low motorway speeds traffic follows even more closely, thus the situation is likely to be exacerbated!

The two biggest steps to preventing this sort of traffic anomaly would be ensuring, through education and appropriate, proportionate enforcement, that drivers did not tailgate, and that they moved left into available gaps when not in the process of overtaking.

I've noticed no change to the provision of scam cams on the J12 (M3) to J16 (M40) stretch (in both directions), and neither has my daily-updated Origin B2.

I've seen dozens of people exceeding the temporary limits this week. Those flashes should have been going off like a disco strobelight. But... nothing.

Internet hoax?

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“For every complex problem, there is a solution that is simple, neat, and wrong.” - H. L. Mencken

I respectfully beg to differ.

Average speed Vs volume of flow are intimitly connected.

Shockwaves occor when people are attempting to travel faster than the volume of flow (safely) allows.

I have asked this before and the awser seems to surprise people.

Q At what average speed does a (hypothetical single lane of) highway atttain its maximum volune of flow (No Vehicles/hour past a fixed observer)




D

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"The road to a police state is paved with public safety legislation"

I think it’s a bit more complicated than that. There are many things that can cause tail backs and traffic waves on motorways. Drivers braking for no reason (sit with their foot on the brake) and drivers behind panic brake, drivers who are too frightened to overtake in lane three when two Lorries are overtaking, drivers who sit in the middle lane all day and won’t pull over, Drivers who sit in lane 3 doing 60-65mph, the list goes on. It doesn’t take much at all to cause a traffic wave when traffic volume is high.

I have noticed that when I’m driving through the SPEC’s system on the A14 the traffic bunches very quickly and then you get the waves starting. Once you get through the SPEC’s and the traffic starts to flow easier it all opens out again. That’s because drivers drive at different speeds which promotes free flowing traffic.

This government to me are not promoting free flowing traffic, I don’t believe that keeping traffic at one speed will make traffic flow any easier.

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Useless laws weaken necessary laws.

I have no idea. But I think it is probably very low.

I think I recall reading that about 14Mph is the optimum

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Re vera, cara mea, mea nil refert

Of course you're welcome to differ, but there are plenty of traffic studies which have drawn the same conclusion. They're out there for the finding.

Personally, I'm not against variable speed limits. This may surprise you, but it seems to work well in Germany. Of course the people in control there seem to be more interested in traffic flow rather than cash from scams...

Maybe this is where we're going wrong?...

Does anyone know why they decided not to put static cameras on NSL motorways in the first place?

I always assumed/hoped that it was because they knew how many people exceeded 70mph, and they were worried that so many people would be caught that there would be a serious backlash against all cameras. But if they're doing what Peter says then perhaps not. Either that or they've got more audacious, which wouldn't surprise me as one of the main things about these car-hating morons seems to be that they take the pee more and more. As they're getting the public grudgingly used to one oppressive measure they're already planning the next one.

I still think though that if more than a certain percentage of drivers started getting sent tickets, it would be a good thing in a way because the number of people who loathed cameras would reach a kind of tipping point. It's sad that some people only turn against cameras once they're caught, but I know it happens from personal experience (not me I might add!)


Unfortunately I don't think it is. Although there have been a number of hoaxes like it, I've seen this one in a lot of places and from some normally reliable sources. I believe that police officers have confirmed it on PH.

But I've not heard anything about cameras being put where they weren't already, and I know parts of the M25 VSL have very few of them, so there presumably won't be too many cases of people getting 12 points in a single journey (because there would have to be relatively few instances of that for the press to have a field day). Even one camera will be a nice little earner though.

It's almost like the government specialises in taking the pee as much as they possibly can, but stopping just short of doing it so much that they're eaten alive by the press and public. Unfortunately, unlike almost everything else, they seem to be pretty damn good at it.


Exactly. I don't really agree that VSLs are a particularly good idea, but even if they were, it's absolutely certain that they will never be implemented in the correct way here. Everyone who's been on that section of the M25 (myself included) seems to have frequently seen the limits set ridiculously low. The people in charge are either totally inept or it's a money-making and/or motorist-persecuting measure. I don't think it's the former because the limits are always too low rather than too high.

To give those who haven't been there a flavour: you know those dot matrix advisory limits that you get on most motorways? You know they're often set at crazily low figures for no apparent reason? Well, that's what happens on the M25 as well, except it happens more often, and of course you've got to obey it. What you then tend to get are some people accelerating and then braking as hard as they can between gantries. Nice and safe (and environmentally friendly) that. Yes, it's their fault for choosing to do it, but if the silly and pointless restriction wasn't there in the first place....

(Has anyone seen any before and after accident stats for the M25 VSL?)

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Paul Smith: a legend.

"The freedom provided by the motor vehicle is not universally applauded, however: there are those who resent the loss of state control over individual choice that the car represents. Such people rarely admit their prejudices openly; instead, they make false or exaggerated claims about the adverse effects of road transport in order to justify calls for higher taxation or restrictions on mobility." (Conservative Way Forward: Stop The War Against Drivers)

A couple of questions regarding this if I may.

1) Is there any confirmation that digital cameras will replace analogue in existing locations only (ie none between M3 (J12) and M40 (J16)?
2) is the change to digital still a single site enforcement policy rather than average speed across the VSL area?

Many thanks

Malcolm

I have contacted Highways agency with regards to getting the above questions answered. They won't however comment on enforcement, so question 2 is presently unconfirmed.

I have asked the question of whether the cameras will be replaced like for like, or whether they will be installed in other gantries that presently do not have cameras.

I will provide you with an update as soon as I know.

Malcolm

Thanks Malcolm, do keep us informed.

My Origin B2 still says there are only 2 sets of cameras between the M40 & M3, one northbound and one southbound between the M4 and M40. I update it daily, so I'll let you all know if anything changes.

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“For every complex problem, there is a solution that is simple, neat, and wrong.” - H. L. Mencken

Hi, newbie here searching for some crumb of comfort across the net.

I've been travelling on the M25 between the M40 and J9 since the road was opened and have avoided speeding tickets from any of the cameras despite being a little over zealous with the right foot from time to time. I have always stuck ridgidly to the variable limit shown, not for any other reason than when it first came out it really seemed to keep the traffic flowing even if it was more slowly that I would like to travel. However, over the course of the past 12 months or so, I've seen a marked decrease in the VSL to do its job, along with a marked increase in the number of people who drive through the limit as though there were no limit imposed, except for a few gantries where I assume they know a camera is installed.

This leads me to believe that the VSL idea would appear to have worked when noone knew where the cameras were and therefore stuck to the limit and now we have effectively created the shockwave effect due to the heavy braking as people approach the known gantries.

One final point. I have always thought that the VSL cameras were inoperative if there was no sign with a limit on the gantry, and hence have not really taken much notice of them, however last night at about 11:45 I was flashed on an almost empty M25 by the last gantry before the A3 on my way to Leatherhead junction ... I await the outcome with baited breath, but I assume that I can expect a present in the post over the next 14 days.

I believe that the M25 cameras where operative but were set to go at anything above 90 however new digital cameras have been installed (so no need for film changes) at these have been set to fire at 80 so if your speed was above 80 there is a chance they will be in touch.

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It is difficult to get a man to understand something when his job depends on not understanding it.

Upton Sinclair

Yesterday I spoke with a very helpful gentleman at the Highways Agency (HA) who has answered the questions that I had outstanding.

Implementation of the new digital cameras is now expected in the Summer, no specific date given, though I am sure if enough people were to contact the Highways agency to request the actual date, they would eventually have to make a statement. Contact details follow.

HA confirmed that the cameras would be a "like for like" replacement of existing camera sites. The implication of going to digital cameras means that they are "on" 24 hours a day with no downtime when the film is full or film is being changed.

I asked about camera provision between J12 -J16 where there currently "appear" to be no cameras in the overhead gantries. HA advised that whilst they could not comment on specific camera location, THERE WILL BE DIGITAL CAMERAS BETWEEN EVERY JUNCTION IN THE VARIABLE SPEED LIMIT ZONE, J10 (A3) to J16 (M40).

As advised by Antera309 there is curently only one camera in each direction between M3 and M40 so this is proliferation of new camera sites.

HA were unable to comment on the actual enforcement policy, however they advised that they are updating the road markings, which indicates that the single site speed limit enforcement will continue. If this was changing to average speed detection we would expect to see additional cameras being installed on slip roads as per the current road works on the M4 between Slough - Maidenhead.

Highways agency can be contacted by e-mail, ha_info@highways.gsi.gov.uk, or by phone 08457 50 40 30/ 0121 335 8300.

I am forwarding this information to as many people as I can to raise awareness, along with a link to the SafeSpeed site. Lets hope it is forwarded as often as the recent "earthquake" emails...

Malcolm