Does VSL technology reach "end of life"?

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tipsynurse
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Does VSL technology reach "end of life"?

Post by tipsynurse »

I remember well when VSL went into the M25 it seemed to work really well - the technology really did seem futuristic and probably was pushing the envelope of what could be done back in 1995.

However, as time has gone on it seems to get more and more unreliable especially with phantom limits in the middle of the night and faulty signage (although the MS2s and 3s seem to be ageing well).

I would imagine this is a result of hardware like sensors dropping out or becoming unreliable, plus a lot of the technology will probably be obsolete now and tied together with unwieldy uncommented software no-one wants to touch.

Was there ever a design life envisaged for smart motorways when they were first installed? I know because this is the UK the system will be forced to hobble on until it actually blows up, but it is a shame what was once a visionary piece of engineering isn't having a happy old age.
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Re: Does VSL technology reach "end of life"?

Post by Nwallace »

All equipment, whether mechanical or electronic has a design life, a MTBF and an ability to fail as it gets older.
If the kit that's in now was put in in 1995 then I'm not surprised it's shonky now.
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Re: Does VSL technology reach "end of life"?

Post by James »

To also be honest I've had a few weird phantom limits on the M1 section south of Sheffield, and this is brand new kit, so age isn't always the issue

Sometimes the kit picks up non-existent problems or is too slow to adapt to the traffic flow when it has cleared
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Re: Does VSL technology reach "end of life"?

Post by tipsynurse »

James wrote:To also be honest I've had a few weird phantom limits on the M1 section south of Sheffield, and this is brand new kit, so age isn't always the issue

Sometimes the kit picks up non-existent problems or is too slow to adapt to the traffic flow when it has cleared
This is a case where it seems to have got noticeably worse/more erratic as time goes by, albeit it is very difficult to objectively assess as one road user.

I wonder whether the newer software may be more risk averse than the original system - obviously somewhat needed for ALR anyway.
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Re: Does VSL technology reach "end of life"?

Post by M4 Cardiff »

One would assume that there is a human override, if due to failure it starts showing abnormal limits, either 40 in clear / no traffic or NSL in a large queue. However, little touch of cynic here, but could there be the wee tiniest possibility that erroneously low limits are left on a little longer than they should be for 'fundraising' purposes?
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Re: Does VSL technology reach "end of life"?

Post by darkcape »

New Smart Motorways are being designed so that equipment can be replaced more easily- this is a major issue with the M42 pilot which is why subsequent schemes sought to reduce the amount of technology on the carriageway.
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Re: Does VSL technology reach "end of life"?

Post by tipsynurse »

M4 Cardiff wrote:One would assume that there is a human override, if due to failure it starts showing abnormal limits, either 40 in clear / no traffic or NSL in a large queue. However, little touch of cynic here, but could there be the wee tiniest possibility that erroneously low limits are left on a little longer than they should be for 'fundraising' purposes?
I wouldn't imagine the Treasury or police give a cut to anyone working in a HE control room.
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Re: Does VSL technology reach "end of life"?

Post by Bryn666 »

Presumably the speed limits are calculated from data gathered by loops. It doesn't take much for a loop to fail, which can cause all kinds of wackiness.

Is there scope for using ANPR to calculate journey speeds and therefore set limits - cameras would presumably be easier to maintain and require fewer lane closures for slot cutting, etc?
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Re: Does VSL technology reach "end of life"?

Post by Johnathan404 »

Bryn666 wrote:Is there scope for using ANPR to calculate journey speeds and therefore set limits - cameras would presumably be easier to maintain and require fewer lane closures for slot cutting, etc?
Surely the technology is already within the speed cameras?
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Re: Does VSL technology reach "end of life"?

Post by Conekicker »

darkcape wrote:New Smart Motorways are being designed so that equipment can be replaced more easily- this is a major issue with the M42 pilot which is why subsequent schemes sought to reduce the amount of technology on the carriageway.
And most definitely not as a cost cutting measure. No. Perish the thought. Yes. Indeed. No. Yes.
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Re: Does VSL technology reach "end of life"?

Post by hoagy_ytfc »

Conekicker wrote:
darkcape wrote:New Smart Motorways are being designed so that equipment can be replaced more easily- this is a major issue with the M42 pilot which is why subsequent schemes sought to reduce the amount of technology on the carriageway.
And most definitely not as a cost cutting measure. No. Perish the thought. Yes. Indeed. No. Yes.
I'd have thought it is explicitly to cut maintenance costs, yes. Are you suggesting this is a bad thing?!
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Re: Does VSL technology reach "end of life"?

Post by Conekicker »

hoagy_ytfc wrote:
Conekicker wrote:
darkcape wrote:New Smart Motorways are being designed so that equipment can be replaced more easily- this is a major issue with the M42 pilot which is why subsequent schemes sought to reduce the amount of technology on the carriageway.
And most definitely not as a cost cutting measure. No. Perish the thought. Yes. Indeed. No. Yes.
I'd have thought it is explicitly to cut maintenance costs, yes. Are you suggesting this is a bad thing?!
I'm suggesting the reduction in level of provision was a measure driven purely by the initial installation cost. Any reduced future maintenance burden was a "happy" side effect.

Whether the level of provision reduction was too much, too little or just right, is another matter.
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Re: Does VSL technology reach "end of life"?

Post by tipsynurse »

Johnathan404 wrote:
Bryn666 wrote:Is there scope for using ANPR to calculate journey speeds and therefore set limits - cameras would presumably be easier to maintain and require fewer lane closures for slot cutting, etc?
Surely the technology is already within the speed cameras?
Speed cameras capture speed immediately after the gantry, you need speeds and vehicle spacings approaching the gantry to know whether to raise the limit.

Aside from that the speed cameras seem to be placed one every dozen or so gantries, I would imagine you need more frequent readings for VSL.
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Re: Does VSL technology reach "end of life"?

Post by Bryn666 »

hoagy_ytfc wrote:
Conekicker wrote:
darkcape wrote:New Smart Motorways are being designed so that equipment can be replaced more easily- this is a major issue with the M42 pilot which is why subsequent schemes sought to reduce the amount of technology on the carriageway.
And most definitely not as a cost cutting measure. No. Perish the thought. Yes. Indeed. No. Yes.
I'd have thought it is explicitly to cut maintenance costs, yes. Are you suggesting this is a bad thing?!
If it is at the expense of safety, then yes.
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Re: Does VSL technology reach "end of life"?

Post by Johnathan404 »

tipsynurse wrote:Speed cameras capture speed immediately after the gantry, you need speeds and vehicle spacings approaching the gantry to know whether to raise the limit.
Why not simply have the camera provide feedback to a gantry further ahead? It would be reporting to a central computer system anyway.
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Re: Does VSL technology reach "end of life"?

Post by hoagy_ytfc »

Bryn666 wrote:If it is at the expense of safety, then yes.
Well that's moved the goalposts onto a different pitch.
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Re: Does VSL technology reach "end of life"?

Post by darkcape »

Conekicker wrote:
hoagy_ytfc wrote:
Conekicker wrote:And most definitely not as a cost cutting measure. No. Perish the thought. Yes. Indeed. No. Yes.
I'd have thought it is explicitly to cut maintenance costs, yes. Are you suggesting this is a bad thing?!
I'm suggesting the reduction in level of provision was a measure driven purely by the initial installation cost. Any reduced future maintenance burden was a "happy" side effect.

Whether the level of provision reduction was too much, too little or just right, is another matter.
No, as I understand it the reduction of technology was driven by two things - the human control room operator (Comprising two sub-issues, the cost of staffing a control room, and that the operating procedures of dynamic hard shoulder schemes weren't ideal), and that the maintenance cost of all the tech was sky-high. Sure, then there's a saving on initial installation - but that is part of the scheme's budget, whereas not all of the ongoing maintenance is covered.

If you averaged out all of the maintenance required on the M42, they would have a lane closure on each carriageway every night of the year, including weekends, such is the maintenance requirement. The cost of that is insane.

Switching to ALR removed the issues with opening/closing the hard shoulder, and made it less confusing for drivers - if you have ALR then operationally it is no different to a D3/4 A-road, which have far lower standards of technology - you can justify the reduction in technology and save yourself the maintenance cost.
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Re: Does VSL technology reach "end of life"?

Post by ellandback »

I've seen plenty of oddities on the M62 j25 to 27 stretch. One blank signal and the others all showing reduced speed limits is pretty common, but I've also seen the opposite. I've also seen a speed limit number without the red circle.

This morning we had a new one though. One set of signals on the HSR section was showing X 60 X 60.

The red Xs were not being wig-wagged, they were just the plain 'non emergency' 'lane closed' signals. I was in lane 1 of the 'proper' road so it didn't particularly concern me, but I noticed that the effect of this was that the red X over the HS was being respected, whereas the red X over lane 2 was being ignored.

What do you reckon - are we attributing this to technical failure? Surely it can't have been intentional to close lane 2 without using wig-wags.

There was no obvious reason for lane 2 to have been closed, for the avoidance of doubt.
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Re: Does VSL technology reach "end of life"?

Post by Matthew »

M4 Cardiff wrote:One would assume that there is a human override, if due to failure it starts showing abnormal limits, either 40 in clear / no traffic or NSL in a large queue. However, little touch of cynic here, but could there be the wee tiniest possibility that erroneously low limits are left on a little longer than they should be for 'fundraising' purposes?
Absolutely not, no.

I think defining failure is not as easy as you'd think. You could perhaps look at a camera and think, "Ooh, that's running ok now, I'll remove the speeds" but CCTV covers a very small section of network and it's not always obvious as to the trigger.

Yes, if equipment said FAIL, FAIL, FAIL then there's something need fixing, but as a safety-critical failure it would be prioritised.
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Re: Does VSL technology reach "end of life"?

Post by AndyB »

I think that all other things being equal, it's driven by MIDAS plus manually reviewing CCTV - so if CCTV operator notices an issue that MIDAS hasn't, they can manually intervene, set a speed limit at a particular gantry, and watch the system then impose the stepping down limits at gantries behind it.

I think lane closures happen in a similar way - operator imposes a closure of a lane at a particular gantry, and the system imposes all necessary related speed limits.
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