The future of smart motorways

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2 Sheds
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Re: The future of smart motorways

Post by 2 Sheds » Fri Jun 11, 2021 17:14

Peter Freeman wrote:
Fri Jun 11, 2021 13:12
There's an extremely interesting safety and capacity article in the latest Highways Magazine Vol 90 #5 pages 28-29. Casts doubt on smart ALR favouring 'controlled' (smarts while retaining shoulder).
Link -
https://edition.pagesuite-professional. ... 217f71d22c
There was a feature on smart motorway safety on Radio 4’s More or less this week. It was broadcast on Wed at 9a.m. and repeated in the last hour. For anyone unfamiliar with the programme it attempts to look behind the headlines and proclamations in the news in an unbiased examination of statistics. The conclusion was Smart motorways are ‘safer’ but probably because speeds are lower and drivers tend to pay more attention. Slightly off topic but there was also a fascinating item on the crazy way bra sizes are measured.

DB617
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Re: The future of smart motorways

Post by DB617 » Fri Jun 11, 2021 17:29

EpicChef wrote:
Fri Jun 11, 2021 16:30
DB617 wrote:
Fri Jun 11, 2021 15:27
From what I've seen, the smart motorway between M4 J24-J28 has been discontinued due to the 50mph permanent speed limit installation. I wasn't sure it would be, but the overhead signals now only indicate advisory limits in congestion. I suspect this is required due to the removal of the 'variable speed limit' signage. Is this the first example of a smart motorway installation being permanently disused?
Perhaps - but what was the need for a fixed limit?
Perhaps with the M4 in Newport being the only managed motorway installation in Wales, Traffic Wales wanted to not bother about it anymore?
The fixed limit enforced by SPECS is one of several in Wales as part of the package required to prove they are addressing excessive NOx and PM emissions. AFAIK there is no precedent to use SPECS and VSL at the same time.

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Re: The future of smart motorways

Post by Bomag » Sat Jun 12, 2021 16:03

DB617 wrote:
Fri Jun 11, 2021 17:29
EpicChef wrote:
Fri Jun 11, 2021 16:30
DB617 wrote:
Fri Jun 11, 2021 15:27
From what I've seen, the smart motorway between M4 J24-J28 has been discontinued due to the 50mph permanent speed limit installation. I wasn't sure it would be, but the overhead signals now only indicate advisory limits in congestion. I suspect this is required due to the removal of the 'variable speed limit' signage. Is this the first example of a smart motorway installation being permanently disused?
Perhaps - but what was the need for a fixed limit?
Perhaps with the M4 in Newport being the only managed motorway installation in Wales, Traffic Wales wanted to not bother about it anymore?
The fixed limit enforced by SPECS is one of several in Wales as part of the package required to prove they are addressing excessive NOx and PM emissions. AFAIK there is no precedent to use SPECS and VSL at the same time.
On VSL each gantry is a terminal sign. Unless the MS4/AMI provided on a section of road meet the spacing requisition in TSM then average camera systems would not be enforceable, see TSM Chapter 8 Part 3 U 2.10.24

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Re: The future of smart motorways

Post by Micro The Maniac » Sun Jun 13, 2021 07:42

Peter Freeman wrote:
Fri Jun 11, 2021 13:12
There's an extremely interesting safety and capacity article in the latest Highways Magazine Vol 90 #5 pages 28-29. Casts doubt on smart ALR favouring 'controlled' (smarts while retaining shoulder).
Link -
https://edition.pagesuite-professional. ... 217f71d22c
Interesting but flawed...

"HE told MPs that 50,995 live lane breakdown incidents were reported o its whole network in 2019, with half of those taking place on conventional motorways."

Let me repeat that: half of those taking place on conventional motorways.

Half of all LIVE LANE breakdowns occurred where THERE WAS A HARD SHOULDER - but presumably they couldn't reach it. On motorways without lane control, or without any plans for stopped vehicle detection.

Pretty much makes the case for MORE smart motorways...

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Re: The future of smart motorways

Post by Peter Freeman » Sun Jun 13, 2021 08:04

Also, quoting from the article -

In its submission to the Transport Select
Committee’s inquiry into the roll-out and safety
of smart motorways, the government-owned
company (HE) stated: ‘ALR motorways are overall
slightly safer than conventional motorways.
Over the period 2015-2019, conventional
motorways had an average of 0.15 live lane
fatalities per hundred million vehicle miles
compared to 0.12 for ALR motorways.’
But a table above this statement shows that
the equivalent five-year average for controlled
motorways was 0.06 – half the fatality rate
of ALR.
In 2019 the ALR fatality rate of 0.14
exceeded that on conventional motorways
(0.13) and was again double that on controlled
motorways (0.07).


Those figures, which relate to live-lane fatalities rather than live-lane breakdowns, are what leads the article to begin with -

Amid all the controversy and
cherry-picked statistics
over the safety of smart
motorways, one key fact is
in danger of being lost in the
mix: motorways that have both traffic control
technology and a permanent hard shoulder are
significantly safer than roads that have only one
of these.


I'm aware that when a HS is present, HS fatalities also occur, and they perhaps are not accounted for above. Needs more analysis ...?

My view on smart motorways, so far, has been favorable, and I believe current developments (more frequent ERA's, and rollout of radar SVD) will go a long way to improve matters. However, all decisions must be based on reliable statistics. I don't know how reliable this article is.

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Re: The future of smart motorways

Post by EpicChef » Sun Jun 13, 2021 08:35

Let the SVD get rolled out completely. We can review the stats then.
Smart motorways are like asbestos: they're the best option until suddenly they're not.

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Re: The future of smart motorways

Post by KeithW » Sun Jun 13, 2021 08:50

Peter Freeman wrote:
Sun Jun 13, 2021 08:04
I'm aware that when a HS is present, HS fatalities also occur, and they perhaps are not accounted for above. Needs more analysis ...?

My view on smart motorways, so far, has been favorable, and I believe current developments (more frequent ERA's, and rollout of radar SVD) will go a long way to improve matters. However, all decisions must be based on reliable statistics. I don't know how reliable this article is.

Quite a long way down this thread is a post I made citing the evidence, you may find it here
https://www.gov.uk/government/publicati ... eport-2019

Not all motorways with live lane running are Smart or Controlle which is why the difference was mentioned.

Overall the number of fatal vasulaties per passenger mile are pretty much the same for convention motorways with hard shoulders and those with all lane running. The one difference was that there were marginally more collisions on smart motorways but marginally fewer people were killed or seriously . This was attributed to the fact that speeds were typically lower than on non managed motorways.

An interesting statistic is the break down of collisions by type. Shunts , were one vehicle runs into another are much less common on managed motorways

At peak periods the personal injury collision rate on managed motorways was 8% lower than that on conventional motorways.


Here are the conclusions
An overarching review of the results of nine ALR schemes has been presented in this report. The purpose
was to gather together evidence from the evaluation of the schemes to present a wider picture of ALR safety
performance. The key findings are presented below, followed by recommendations.
Collision and casualty rates
Overall, the results show strong safety performance of ALR. There has been a statistically significant
improvement in personal injury collision rate and casualty rate, outperforming the national trend by 12% and
18%, respectively. Across the 9 schemes evaluated there has been an absolute reduction of 28% in the
casualty rate.

FWI rate is the key performance metric to be assessed and while a statistical analysis could not be
performed on this due to the weighted nature of FWI, overall, there has been an absolute reduction of 0.10
per hmvm in the FWI rate. This is equivalent to a reduction of 1 serious injury, or 10 slights, per hundred
million vehicle miles, because of the FWI equation (see Section 3.1). The reduction is 0.09 per hmvm better
than the national motorway trend.

There has been a 0.15 per hmvm worsening in the KSI collision rate and 0.16 per hmvm in the KSI casualty
rate. The changes were not statistically significant, meaning there was effectively no change; they were not a
result of ALR. In addition, the magnitude of these changes was relatively small compared to those of the
other ALR performance measures. Therefore, in summary, the results clearly show that the ALR concept has
improved safety overall.

To gauge the magnitude of the ‘CRASH effect’, correction factors of 5% and 15% were applied to the
casualty data. The results suggest that without the ‘CRASH effect’, the KSI casualty rate might have
worsened by a lesser degree and the FWI rate might have improved more, compared to the rates we have
seen with no adjustment.

In summary, the results show that the overall performance of the ALR schemes evaluated has improved.
Against a background of increasing flows, the safety objective has been met which is no increase in number
or rate of fatal and weighed injury (FWI) casualties.
As with other RTC's the overiding cause of such incidents is driver error, which includes not just running into stationary objects but side swiping other vehicles, single vehicle accidents due to loss of control and the occasional wrong way driver.

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Re: The future of smart motorways

Post by KeithW » Sun Jun 13, 2021 08:54

EpicChef wrote:
Sun Jun 13, 2021 08:35
Let the SVD get rolled out completely. We can review the stats then.
In my humble opinion a continuous evaluation as this proceeds is rather more useful, if nothing else it will prevent the issues that arose when trials of motorway lighting failed to provide the large reduction in accident rates that was used to justify it.

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Re: The future of smart motorways

Post by Debaser » Sun Jun 13, 2021 09:04

KeithW wrote:
Sun Jun 13, 2021 08:50
An interesting statistic is the break down of collisions by type. Shunts , were one vehicle runs into another are much less common on managed motorways
On congested pre-improved upgraded modified motorways usually by far the greatest collision type is shunts, due to the stop-start nature of the flow in the peak hours. They usually go unrecognised by members of the public who think motorway = high speed = '5-vehicle horror smash' as the type of collision you'd expect.

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Re: The future of smart motorways

Post by Peter Freeman » Sun Jun 13, 2021 10:06

The thrust of the June 2021 Highways Magazine article was not the safety comparison of ALR and DHS against conventional motorway, which it recognised as not greatly different. Its point was that the rarer 'controlled motorway' standard (technology added and HS retained) is safer than either, by a large factor. The March 2020 HE publication (Smart Motorway All Lane Running Overarching Safety Report 2019) cited by Keith focusses mainly on ALR, to a lesser degree on DHS, and little on Controlled.

Having reviewed the HE document, I can't see the figures that are quoted in the Highways Mag article. They were reportedly in another document, HE's submission to 'The Transport Select Committee's Inquiry into Smart Motorways'.

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Re: The future of smart motorways

Post by Conekicker » Sun Jun 13, 2021 10:21

Micro The Maniac wrote:
Sun Jun 13, 2021 07:42
Peter Freeman wrote:
Fri Jun 11, 2021 13:12
There's an extremely interesting safety and capacity article in the latest Highways Magazine Vol 90 #5 pages 28-29. Casts doubt on smart ALR favouring 'controlled' (smarts while retaining shoulder).
Link -
https://edition.pagesuite-professional. ... 217f71d22c
Interesting but flawed...

"HE told MPs that 50,995 live lane breakdown incidents were reported o its whole network in 2019, with half of those taking place on conventional motorways."

Let me repeat that: half of those taking place on conventional motorways.

Half of all LIVE LANE breakdowns occurred where THERE WAS A HARD SHOULDER - but presumably they couldn't reach it. On motorways without lane control, or without any plans for stopped vehicle detection.

Pretty much makes the case for MORE smart motorways...
Except that also means that half the live lane breakdowns occurred on SM sections, which are only a small part of the network. Make more ALR and the number of live lane breakdowns will go through the roof.

Also - and critically - how many breakdowns made it to the hard shoulder? This number will, I suspect, be far higher than the live lane breakdowns where there is a hard shoulder. So more ALR would mean those breakdowns would add significantly to the number of live lane breakdowns.
Patience is not a virtue - it's a concept invented by the dozy beggars who are unable to think quickly enough.

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Re: The future of smart motorways

Post by Bryn666 » Sun Jun 13, 2021 11:45

The future safety problems caused by less proactive maintenance because there's no way to undertake tasks without closing live lanes will be the one to watch.

Either get used to motorways being shut nearly every single night or roadworks just not being done and defects start to contribute to collisions.
Bryn
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She said life was like a motorway; dull, grey, and long.

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Re: The future of smart motorways

Post by XC70 » Mon Jun 14, 2021 19:40

2 Sheds wrote:
Fri Jun 11, 2021 17:14
Peter Freeman wrote:
Fri Jun 11, 2021 13:12
There's an extremely interesting safety and capacity article in the latest Highways Magazine Vol 90 #5 pages 28-29. Casts doubt on smart ALR favouring 'controlled' (smarts while retaining shoulder).
Link -
https://edition.pagesuite-professional. ... 217f71d22c
There was a feature on smart motorway safety on Radio 4’s More or less this week. It was broadcast on Wed at 9a.m. and repeated in the last hour. For anyone unfamiliar with the programme it attempts to look behind the headlines and proclamations in the news in an unbiased examination of statistics. The conclusion was Smart motorways are ‘safer’ but probably because speeds are lower and drivers tend to pay more attention. Slightly off topic but there was also a fascinating item on the crazy way bra sizes are measured.
I love more or less so I searched this out.

A good article, just spoiled at the end where they said that smart motorways were enforced by speed/distance cameras....

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Re: The future of smart motorways

Post by Bendo » Mon Jun 14, 2021 19:53

Conekicker wrote:
Sun Jun 13, 2021 10:21
Micro The Maniac wrote:
Sun Jun 13, 2021 07:42
Peter Freeman wrote:
Fri Jun 11, 2021 13:12
There's an extremely interesting safety and capacity article in the latest Highways Magazine Vol 90 #5 pages 28-29. Casts doubt on smart ALR favouring 'controlled' (smarts while retaining shoulder).
Link -
https://edition.pagesuite-professional. ... 217f71d22c
Interesting but flawed...

"HE told MPs that 50,995 live lane breakdown incidents were reported o its whole network in 2019, with half of those taking place on conventional motorways."

Let me repeat that: half of those taking place on conventional motorways.

Half of all LIVE LANE breakdowns occurred where THERE WAS A HARD SHOULDER - but presumably they couldn't reach it. On motorways without lane control, or without any plans for stopped vehicle detection.

Pretty much makes the case for MORE smart motorways...
Except that also means that half the live lane breakdowns occurred on SM sections, which are only a small part of the network. Make more ALR and the number of live lane breakdowns will go through the roof.

Also - and critically - how many breakdowns made it to the hard shoulder? This number will, I suspect, be far higher than the live lane breakdowns where there is a hard shoulder. So more ALR would mean those breakdowns would add significantly to the number of live lane breakdowns.
It's a bit of a pointless stat really. Breakdown on an ALR section and you have obviously broken down in a live lane. The important question is, how long did it remain a line lane after the breakdown.

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Re: The future of smart motorways

Post by Conekicker » Mon Jun 14, 2021 21:02

Bendo wrote:
Mon Jun 14, 2021 19:53
It's a bit of a pointless stat really. Breakdown on an ALR section and you have obviously broken down in a live lane. The important question is, how long did it remain a line lane after the breakdown.
It would be illuminating to know what percentage of vehicles make it to an ERA. Because once they do, the length of the ERA, when you take the size of a recovery vehicle into account, makes it more or less unavailable to other ailing vehicles.

The amount of time a vehicle remains on the hard shoulder is more or less irrelevant, given that most vehicles in that position aren't hit.

I agree the the exposure time of vehicles in live lanes - and to a lesser extent on the HS - should be looked at.

The Highways magazine article makes it very clear that controlled motorways are far safer then ALR.
Patience is not a virtue - it's a concept invented by the dozy beggars who are unable to think quickly enough.

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Re: The future of smart motorways

Post by Patrick Harper » Tue Jun 15, 2021 14:41

I guess the ultimate question would be whether it's worth converting D4ALR motorways back to D3M whilst keeping the tech added during the ALR schemes.
Last edited by Patrick Harper on Tue Jun 15, 2021 16:50, edited 1 time in total.
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Re: The future of smart motorways

Post by Bryn666 » Tue Jun 15, 2021 15:37

Patrick Harper wrote:
Tue Jun 15, 2021 14:41
I guess the ultimate question would be whether it's worth converting D4ALR motorways back to D3M whilst keeping the tech added during the ALR scheme.
Doubtful, the M6 J16-19 is a much improved motorway despite lack of hard shoulder, knocking this back down to D3M would cause problems to say the least.
Bryn
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Re: The future of smart motorways

Post by KeithW » Tue Jun 15, 2021 16:35

Patrick Harper wrote:
Tue Jun 15, 2021 14:41
I guess the ultimate question would be whether it's worth converting D4ALR motorways back to D3M whilst keeping the tech added during the ALR scheme.
In a word no, the capacity would drop by up to 25% with an obvious increase in congestion.

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Re: The future of smart motorways

Post by KeithW » Tue Jun 15, 2021 16:47

Bryn666 wrote:
Sun Jun 13, 2021 11:45
The future safety problems caused by less proactive maintenance because there's no way to undertake tasks without closing live lanes will be the one to watch.

Either get used to motorways being shut nearly every single night or roadworks just not being done and defects start to contribute to collisions.
Realistically apart from minor pothole fixing and gantry sign work how much maintenance can be done on major conventional motorways without a closure anyway ?

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Re: The future of smart motorways

Post by Bryn666 » Tue Jun 15, 2021 18:03

KeithW wrote:
Tue Jun 15, 2021 16:47
Bryn666 wrote:
Sun Jun 13, 2021 11:45
The future safety problems caused by less proactive maintenance because there's no way to undertake tasks without closing live lanes will be the one to watch.

Either get used to motorways being shut nearly every single night or roadworks just not being done and defects start to contribute to collisions.
Realistically apart from minor pothole fixing and gantry sign work how much maintenance can be done on major conventional motorways without a closure anyway ?
Plenty of maintenance tasks that can be undertaken using hard shoulder closures, and
for central works works the hard shoulder is used as a running lane and traffic pushed away - with smart motorways you can't do that, everything will require capacity reductions if not full closures.
Bryn
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She said life was like a motorway; dull, grey, and long.

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