RE: PH Blog: let's talk about SPECS
Discussion
MrTickle said:
Surely with ACPO guidelines at 10%+2mph giving 57mph in a 50, plus some speedo inaccuracy likely to take that to 59-60, then sticking to 'around' and indicated 55mph will always be safe from a dreaded NIP?
Isn't the 10% + 2mph think just a guideline? Also, isn't the 10% already allowing for any speedo inaccuracy? They can "get you" for 51mph in a 50 if they want.jaik said:
Isn't the 10% + 2mph think just a guideline? Also, isn't the 10% already allowing for any speedo inaccuracy? They can "get you" for 51mph in a 50 if they want.
You can get 'done' at any speed over the limit, but in reality cameras should follow ACPO guidelines when being set IIRC. A copper spotting you driving lick a knobber at 51 in a 50 is perfectly in his rights to pull you over.
From the factory, your car speedo will be set to read high. Most cars I've owned have speedos that read between 8 and 10% high. This is a legal thing that prevents manufacturers from being sued by motorists claiming their speedo only said 30 when clocked doing 36.
There is also a camera tolerance, which is avoided by setting the camera to 10% + 2mph over the legal limit.
Adding those together, a 50 camera will be set to 57mph, at a real 57 mph your car speedo will show 62 to 63mph. Knowing all this I cruise through all speed cameras at 8-10mph over the stated limit, knowing that I'm only actually doing about 2mph over the limit.
This all worked well until I had a car with a speedo that had been recalibrated from kph to mph. That car speedo was accurate to within 1%, I got caught out once before I realised.
There is also a camera tolerance, which is avoided by setting the camera to 10% + 2mph over the legal limit.
Adding those together, a 50 camera will be set to 57mph, at a real 57 mph your car speedo will show 62 to 63mph. Knowing all this I cruise through all speed cameras at 8-10mph over the stated limit, knowing that I'm only actually doing about 2mph over the limit.
This all worked well until I had a car with a speedo that had been recalibrated from kph to mph. That car speedo was accurate to within 1%, I got caught out once before I realised.
The solution to optimization lies in either the cars onboard computer, or satnav units trip stats function! I work on the 10%+2 theory which means a real 57mph is required to trigger a NIP. In most cars (certainly my Rover 75) that's an indicated 60mph+, so I simply reset my trip computer average speed at every camera and use cruise to maintain an accurate average (oddly, the trip computer average speed is always 1.5-2mph lower than indicated and a similar amount more than real GPS verified). You move considerably faster than others driving to a speedo indicated 50mph when doing a *real* 56mph..... Those that pass @ +20mph? I assume illegal or stupid....
Okay, my memory of all this isn’t 100% so please excuse any schoolboy errors … but a few of us from the local Porsche club went along to our local Safety Camera Partnership for a chat with the head honcho a year or two back. He gave us some interesting pointers. Bear in mind also that this was in Scotland and may be different south of the border. (Also, here in Scotland we have SPECS cameras as permanent fixtures on some major roads—not just on temporary roadworks etc.)
SPECS cameras are wildly inaccurate at measuring speed, so the authorities allow a wider margin of ‘grace’ than with a regular GATSO. There was off-the-record chat that an actual 67 or so was about right for a 50 zone.
The cameras and management thereof is all digital, so in theory all the cameras can be always on. In practice, they are not. This will eventually change as the monitoring systems (ie. civilian employees and coppers) catch up.
At any given time, any two cameras can be a ‘measuring pair’. So you never know whether you’re being measured as an average speed between the first and last camera, the third and fourth, or the tenth and twentieth, etc. It could be any two at all, but it’s only ever one pair at a given time. This is to randomise the parameters a bit and allow for the fact that most drivers are using junctions to join/leave in the middle of the SPECS zone—not travelling the whole distance.
As a percentage of the overall NIPs issued in a given month, SPECS cameras are only generating a TINY amount. The majority (believe it or not) come from red light cameras. (Again, this could just be true for our part of the country—I don’t recall.)
SPECS cameras are wildly inaccurate at measuring speed, so the authorities allow a wider margin of ‘grace’ than with a regular GATSO. There was off-the-record chat that an actual 67 or so was about right for a 50 zone.
The cameras and management thereof is all digital, so in theory all the cameras can be always on. In practice, they are not. This will eventually change as the monitoring systems (ie. civilian employees and coppers) catch up.
At any given time, any two cameras can be a ‘measuring pair’. So you never know whether you’re being measured as an average speed between the first and last camera, the third and fourth, or the tenth and twentieth, etc. It could be any two at all, but it’s only ever one pair at a given time. This is to randomise the parameters a bit and allow for the fact that most drivers are using junctions to join/leave in the middle of the SPECS zone—not travelling the whole distance.
As a percentage of the overall NIPs issued in a given month, SPECS cameras are only generating a TINY amount. The majority (believe it or not) come from red light cameras. (Again, this could just be true for our part of the country—I don’t recall.)
Edited by poprock on Tuesday 15th May 12:11
Dr Mike Oxgreen said:
spiritof'76 said:
i just keep changing lanes after every one as a precaution against error just because some unnamed person told me that's what you have to do
That won't keep you safe, I'm afraid.Firstly, I believe the advice is out-of-date. I was told that when SPECS camera systems first came in, they only did the formal proving for vehicles remaining in the same lane. My suspicion is that they ran out of time and/or money during the proving process. So I believe it was the case that if a car had changed lane between the two paired cameras, a conviction could not be made. That's not because the system couldn't determine your speed - just that it hadn't been formally proved.
However, I've been told that loophole no longer exists. The formal testing has now been done.
But... the advice to keep changing lanes was never particularly useful anyway. The problem is that in a long SPECS zone with multiple cameras, you don't know which cameras are paired with which: the pairs could be overlapped. In other words, the second camera isn't necessarily paired with the first one: the first could be paired with the third, and the second paired with the fourth. So changing lanes and then changing back again puts you back in the same lane for the third camera, and bam!
How about this,,,,,,, Crude but effective
robinessex said:
My Neighbour was done for 54mph thro' the roadworks on the M25. At 11pm on a virtually empty road.
Call me cynical, but unless you've seen the NIP, i'm always a little suspicious of people who claim for being done 'just' over the limit (especially when it comes with the standard 'it's ridiculous! I was being perfectly safe as it was at night on an empty road!')- my mum for example who claims her NIP for speeding in a 30 was 33mph, but it changes randomly between 31-33?! People really don't like being labelled bad/ inattenitve drivers and so I think info passed on can sometimes be a little 'out'.Edited by Si_man306 on Tuesday 15th May 12:17
To the best of my knowledge, the following is true and from a reasonable source.
Background:
This was told to a colleague of mine by a member of a company that makes ANPR cameras at a trade show. For reference, the company I work for also makes traffic monitoring devices, and now ANPR cameras, although ours aren't for enforcement, as this requires a lot of type approval work, so don't hate me.
Info:
The lane changing was just to do with pairs of cameras, you had to be seen between a pair. I don't think this is the case any more, as the plate is sent back to a database, and the matching done there, presumably across all the cameras. If this isn't the case, from a software developer's point of view it should be, so will be like that eventually.
The interesting one is the question of how different lanes affect the distance you've travelled depending on curvature of the road.
APPARENTLY, the average speed has to be calculated based on the straight line distance between any pair of cameras. Otherwise, ignoring the ACPO 10% + 1 etc. somebody who was travelling at 50mph on the inside of all the corners, could feasibly arrive before someone travelling at 51mph on the outside, and so there is the possibility for some blurring of the lines.
Hence using the straight line distance as the only fair and irrefutable measurement of the distance the driver travelled.
So if the road bends, you can get away with a higher speed, in theory.
Am I going to test this out? No. Sat-nav verified 54mph is enough for me.
Background:
This was told to a colleague of mine by a member of a company that makes ANPR cameras at a trade show. For reference, the company I work for also makes traffic monitoring devices, and now ANPR cameras, although ours aren't for enforcement, as this requires a lot of type approval work, so don't hate me.
Info:
The lane changing was just to do with pairs of cameras, you had to be seen between a pair. I don't think this is the case any more, as the plate is sent back to a database, and the matching done there, presumably across all the cameras. If this isn't the case, from a software developer's point of view it should be, so will be like that eventually.
The interesting one is the question of how different lanes affect the distance you've travelled depending on curvature of the road.
APPARENTLY, the average speed has to be calculated based on the straight line distance between any pair of cameras. Otherwise, ignoring the ACPO 10% + 1 etc. somebody who was travelling at 50mph on the inside of all the corners, could feasibly arrive before someone travelling at 51mph on the outside, and so there is the possibility for some blurring of the lines.
Hence using the straight line distance as the only fair and irrefutable measurement of the distance the driver travelled.
So if the road bends, you can get away with a higher speed, in theory.
Am I going to test this out? No. Sat-nav verified 54mph is enough for me.
Edited by SturdyHSV on Tuesday 15th May 12:17
Kenzle said:
Has anyone on here actually been sent a NIP for speeding through a SPECS? I have yet to hear of a single case of anyone ever being caught by these things.
My Mum [!!!!!!!!!!!!!!!!!!!] in her eco w
ker car, M11.I always thought adhering to such a stupid limit for miles was very dangerous, Cruise Control is the only answer, it leaves you free to actually watch the road for hazards, always my preferred course of action as a biker.
My only speeding conviction, 95 in a 40, bike, I defended myself and excused the speed with the simple and very effective defence "I was not looking at the speedometer, I knew I was going fast, you barely have time to look at it and focus, read it, then look back at the road... at legal speeds, it would be very unsafe to do so at speed. A £200 fine, 3 points, seen car drivers banned on that stretch for 70.
In most cars, I just back down to 51/52mph and flick the cruise control on - in my view it's not worth risking three points for the sake of an extra couple of mph.
In the Jensen its a complete nightmare though, the speedo flicks from 40-60mph, and is so inaccurate that you don't have a clue how fast you're going! I just get down to around 50 ish well before the cameras, then slot in with 'traffic speed' and keep fingers crossed that they're all law abiding motorists!
In the Jensen its a complete nightmare though, the speedo flicks from 40-60mph, and is so inaccurate that you don't have a clue how fast you're going! I just get down to around 50 ish well before the cameras, then slot in with 'traffic speed' and keep fingers crossed that they're all law abiding motorists!
I always had a fairly benign relationship with SPECS cameras as I believed they were only used in roadworks, which I considered to be fair enough.
However, I went through what looked like a permanent set up on the M4 last year, where there were SPECS cameras between at least two junctions at Newport. I asked my father, who lives near there, about them and he told me they were indeed permanent and had been there for a while.
I haven't been that way in a while so I don't know if they're still there. If they are they must be nightmare on a wide clear motorway in the middle of the night!
Happy to be put right if I'm wrong about this.
However, I went through what looked like a permanent set up on the M4 last year, where there were SPECS cameras between at least two junctions at Newport. I asked my father, who lives near there, about them and he told me they were indeed permanent and had been there for a while.
I haven't been that way in a while so I don't know if they're still there. If they are they must be nightmare on a wide clear motorway in the middle of the night!
Happy to be put right if I'm wrong about this.
Kenzle said:
Has anyone on here actually been sent a NIP for speeding through a SPECS? I have yet to hear of a single case of anyone ever being caught by these things.
Yes, a mate of mine lost his licence due to them. He had a very blasé attitude towards them, thinking "nobody gets caught by them" and changing lanes could fool them. After 2 weeks of driving through them every day to and from work he went from clean licence to 12 + points and a court date!Kenzle said:
Has anyone on here actually been sent a NIP for speeding through a SPECS? I have yet to hear of a single case of anyone ever being caught by these things.
http://www.bbc.co.uk/news/uk-wales-11937954What is really needed is one of these, a powered flip down numberplate thingy:
http://www.youtube.com/watch?v=Q5yrB8xitb0
I bought the manual 'show n go' one for car shows from summit racing, I didn't trust myself having the remote control version
http://www.youtube.com/watch?v=Q5yrB8xitb0
I bought the manual 'show n go' one for car shows from summit racing, I didn't trust myself having the remote control version
Edited by robinandcamera on Tuesday 15th May 12:34
Edited by robinandcamera on Tuesday 15th May 12:35
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