M4 Junction 3 to 12 Smart Motorway

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Bryn666
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Re: M4 Junction 3 to 12 Smart Motorway

Post by Bryn666 » Mon Sep 20, 2021 16:25

Chris5156 wrote:
Mon Sep 20, 2021 14:01
ChrisH wrote:
Mon Sep 20, 2021 13:20
When I queried these with HE a year or so ago they came back with responses around doing large areas of resurfacing, which weren't possible with overnight closures.
What absolute bobbins. I wonder if money plays a part - are they doing the job more cheaply than if they had kept the road open through routine jobs like that?
If anything setting up these closures is probably more labour intensive as you have to guard the site entries to prevent incursions by Mr P. Leb. I have long had a sneaking suspicion there's some kind of motorway TTM cartel that National England Agency for Highways are happy to facilitate, there's no other way you can explain all the innovation drivel that's been foisted upon the innocent network lately.
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Re: M4 Junction 3 to 12 Smart Motorway

Post by DB617 » Thu Sep 23, 2021 14:32

A303Chris wrote:
Mon Sep 20, 2021 10:45
It seems the vehicle detection equipment has now been installed between J8/9 and J12, with the latest newsletter saying four lanes will be open fully with a 60mph limit from October while they test the technology and 4 lanes with a 70 mph limit by the end of the year.

However, what is annoying is the constant weekend closures of the road between J8/9 and J3, some section is closed every weekend or overnight. Last Tuesday was a classic, M4 was closed J7 to J5 overnight, while the M40 was closed between J3 and J4 and the A404 between the A308 and A4130, talk about coordination not.

However why in the south east as was the case on the M3 and M23 works, do they need so many weekend closures, they do not seem to be needed on the M6 and M1 works. It is a pain and as I have family near Datchet basically the closures just screw the village every weekend.
This type of discoordination is absolutely shocking. I am starting to think that motorway closures, nationally important as they are, should fall to ministerial approval as a daily business item for the minister. The effect on people and business is too great, closing three trunk roads in the same region at the same time.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by KeithW » Thu Sep 23, 2021 15:53

DB617 wrote:
Thu Sep 23, 2021 14:32

This type of discoordination is absolutely shocking. I am starting to think that motorway closures, nationally important as they are, should fall to ministerial approval as a daily business item for the minister. The effect on people and business is too great, closing three trunk roads in the same region at the same time.
I rather doubt that the minister (Baroness Vere) is going to do that given that she is in charge of several other transport related departments as well as Highways England, namely motoring agencies (DVSA, DVLA, VCA) buses and taxis, light rail and devolution (including London transport). Even if she had this role she hardly has the professional background to do it given that her main experience seems to have been in financial control.

The most appropriate on the face of it would be one of the directors of Highways England but unsurprisingly only one of them seem to have a previous background in engineering of any sort and that was in the nuclear industry. I am afraid we have gone the way of the USA and the only way to get a senior job is to be a glorified accountant,.

What I loved about the old CEGB was that to be a director or senior manager you needed to be first and foremost a qualified and experienced engineer. When one of them visited us on Dungeness B they would insist on a full technical briefing then go and look at progress for themselves.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by WHBM » Thu Sep 23, 2021 17:29

Chris5156 wrote:
Mon Sep 20, 2021 11:34
I can understand needing to close a road at certain points in a major project to carry out certain jobs, like bridge demolition, but I can't understand why there have needed to be this many closures over a period now running in to years. It feels a bit like a project plan made for the convenience of the project and not for the convenience of the travelling public.
... and it's not just weekends either. I notice the "overnight" closures are getting progressively earlier. I came back up full length of the M3 on Tuesday evening this week and the closures (more than one) were kicking off by 8pm. I also spotted the actual physical closure going in well in advance of the stated time, one more than 20 minutes beforehand.

This has long been a feature of the Limehouse Link overnight maintenance closures, ostensibly signed as 10pm to 6am, they regularly have it shut by 9.45pm, but finish the work and open up again by say 1.30am, when there's hardly anything about - and those who know about it have diverted away anyway.

Doing it for the project's cost convenience is known as a "Project-led timescale". At the competitive stage the contractors will present how they will schedule to minimise disruption, but after they have got the job it's all about minimising every cost, as the Construction Director will be emphasising to the Managing Engineer, given they will be getting the same revenue for completing it, and disruption be blowed for what's not formally stipulated in the contract.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by DB617 » Fri Sep 24, 2021 12:19

KeithW wrote:
Thu Sep 23, 2021 15:53

I rather doubt that the minister (Baroness Vere) is going to do that given that she is in charge of several other transport related departments as well as Highways England, namely motoring agencies (DVSA, DVLA, VCA) buses and taxis, light rail and devolution (including London transport). Even if she had this role she hardly has the professional background to do it given that her main experience seems to have been in financial control.

The most appropriate on the face of it would be one of the directors of Highways England but unsurprisingly only one of them seem to have a previous background in engineering of any sort and that was in the nuclear industry. I am afraid we have gone the way of the USA and the only way to get a senior job is to be a glorified accountant,.

What I loved about the old CEGB was that to be a director or senior manager you needed to be first and foremost a qualified and experienced engineer. When one of them visited us on Dungeness B they would insist on a full technical briefing then go and look at progress for themselves.
Absolutely agreed. The concept of climbing the ranks to become a leader has been all but abandoned, probably in lock step with the corporatisation of many parts of the national infrastructure. Now we have graduate managers running everything who think they can sign for critical pieces of nationally important work just because they reckon they're more highly qualified to 'manage people' (which they are invariably also bad at). Essentially the entire corporate sector is suffering from the old military problem of forces of highly experienced and motivated experts being lead by butter bars with degrees in humanities and accounting.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by EpicChef » Fri Sep 24, 2021 20:37

Any updates from locals?
Smart motorways are like asbestos: they're the best option until suddenly they're not.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by ChrisH » Thu Oct 07, 2021 16:53

I emailed HE a while ago to ask about two changes to the scheme since DCO: firstly the lane drops at almost all intermediate junctions; and secondly the lack of lighting. Their response came a few days ago and I paste below for information:
The Scheme was originally designed to design standards informed by Interim Advice Note 161/13. At that time, the Interim Advice Note (IAN) considered that Through Junction Running (TJR) (i.e. facilitating 4 lanes through running by changing the existing layout of junctions which require a lane drop) should be the preferred operating regime at all junctions in Smart Motorway schemes, except at motorway-motorway interchanges and terminal junctions. The updated IAN 161/15 published in November 2015 alongside recent feedback from operational Smart Motorway All Lane Running (SM-ALR) schemes recommends that the most appropriate junction layout for that scheme should be implemented taking into account operational and physical constraints for each junction, rather than requiring TJR to be put in place for the entire scheme.

In light of this update to the design standards, an operational assessment of the entire scheme has been carried out. The aim of this assessment has been to determine the suitability of either a TJR or no-TJR layout for the junctions at the scheme design year (2037). This review has analysed operational, environmental and safety factors and potential construction time and value for money. During this phase concern was raised around the potential, with TJR, of queuing affecting the mainline due to junction capacity particularly at junction 6, 8/9 and 11. Similar situations have arisen on the M1 smart motorway schemes, where queuing in lane 1 of the mainline led to congestion and a break down in traffic flow. Following extensive modelling and assessment the review concluded that a move away from TJR at junctions 6, 8/9 and 11 to no-TJR could be accommodated without detriment to safety, traffic flows or the 15-year design life of the scheme. These changes have been discussed with local authorities where these junctions reside.

These factors have been used to recommend a preferred operating regime of either TJR or no-TJR for those junctions where TJR had been proposed under IAN 161/13 and the granted Development Consent Order (DCO). National Highways will be bringing forward an application to amend the DCO to reflect this changed design in due course. In respect of junction 5, during the detail design phase for junction 5, survey information indicated that the original proposal to asymmetrically widen the bridge to 4 lanes in both directions would be more complex than previously understood due to the nature of the post tensioning in the bridge. Given this change, a review of future traffic figures concluded that 3 lanes with variable mandatory speed limits will be able to cope with traffic flows through the full 15 year design life of the scheme, without detriment to traffic flow. As such we're proposing that junction 5 at Langley will remain 3 lanes in both directions when the smart motorway is opened.

In regards to the lighting, the original DCO intended to provide a like for like lighting provision. Again during detail design optimisation, a review of standards demonstrated that sections of the M4 no longer justified lighting provision. As such Highways England (now National Highways) proposed through a re-discharge of the DCO Requirement 9 to remove lighting from the M4, the current design is to light from junction 3 to 7 only. This was proposed to consultees and signed off by the secretary of state on 24th October 2019. The re-discharge can be found here.
To me the most notable thing about this is that an £800m scheme, with a 4 year construction period, only has a 15 year design life.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Bryn666 » Thu Oct 07, 2021 17:44

ChrisH wrote:
Thu Oct 07, 2021 16:53
To me the most notable thing about this is that an £800m scheme, with a 4 year construction period, only has a 15 year design life.
It's not surprising though, got to keep the big boys consultancy cartel in business - it'll take 15 years to get the next scheme through the political motions during which vast resources can be soaked up in design and production of glossy brochures.

Cynical, moi?
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Re: M4 Junction 3 to 12 Smart Motorway

Post by Herned » Thu Oct 07, 2021 18:21

£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Chris5156 » Thu Oct 07, 2021 18:45

Herned wrote:
Thu Oct 07, 2021 18:21
£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?
And designed that way in case of traffic queueing back onto the mainline from the roundabout, not by looking at the requirements of predicted traffic flows. Or even current traffic flows, come to that.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by WHBM » Thu Oct 07, 2021 19:24

This change at J5 does explain why considerable works alongside the bridges started about four years ago, then were abandoned. I think I wrote about it here at the time.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Bryn666 » Thu Oct 07, 2021 19:50

Herned wrote:
Thu Oct 07, 2021 18:21
£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?
No, you're definitely not.
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Re: M4 Junction 3 to 12 Smart Motorway

Post by jackal » Thu Oct 07, 2021 21:00

J4B to J5 is not widened either... well not properly, it squeezes back down to four lanes under the Sutton Lane bridge. I think they basically didn't want the hassle of replacing this bridge, which is close to residential properties and would require land outside the highway boundary. Widening through J5 would be comparatively easy, but Sutton Lane bridge leaves no space for any merge other than a 3+1 lane gain. So one bridge means the entire approach to the M25 is compromised.

M4 ALR Sutton Lane - Copy.JPG

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Re: M4 Junction 3 to 12 Smart Motorway

Post by WHBM » Fri Oct 08, 2021 01:05

jackal wrote:
Thu Oct 07, 2021 21:00
J4B to J5 is not widened either... well not properly, it squeezes back down to four lanes under the Sutton Lane bridge. I think they basically didn't want the hassle of replacing this bridge, which is close to residential properties and would require land outside the highway boundary. Widening through J5 would be comparatively easy, but Sutton Lane bridge leaves no space for any merge other than a 3+1 lane gain. So one bridge means the entire approach to the M25 is compromised.
I have written here before that very regular use of the J5-J4B section over the years has passed more accidents on the eastbound section here than anywhere else I know, and I suspect in some years it's more than half that year's total encounters. The hard shoulder is littered with broken glass and bumpers etc. The principal cause is blocking back from the M25 exit at J4B, which can extend in lane 1 right back to the lane gain from J5, so substantial numbers in what becomes lane 2 have to merge into stopped traffic. If joining at J5 towards London the most effective route is to get right across the layout into lane 4, the others being a disorganised mass of stopped and squeezing past vehicles. It really needed two exiting lanes to the M25, instead of one out of four for what seems more than half the volume.

Looking at the diagram above, the additional lane gain east of Sutton Lane is on the right, the through London lanes. That's the last thing that was needed.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Peter Freeman » Fri Oct 08, 2021 01:05

Chris5156 wrote:
Thu Oct 07, 2021 18:45
Herned wrote:
Thu Oct 07, 2021 18:21
£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?
And designed that way in case of traffic queueing back onto the mainline from the roundabout, not by looking at the requirements of predicted traffic flows. Or even current traffic flows, come to that.
That's the thing that struck me too. Slip road traffic queuing back from the junction onto the mainline is best addressed by action at the junction; or, at the very least, by action on the slip road. But no - instead, let's allow the queue to form on lane 1, effectively a very long and possibly dangerous slip road, and compromise the capacity and fundamental effectiveness of our improvement scheme by dropping the lane from the mainline.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Chris5156 » Fri Oct 08, 2021 09:11

Peter Freeman wrote:
Fri Oct 08, 2021 01:05
Chris5156 wrote:
Thu Oct 07, 2021 18:45
Herned wrote:
Thu Oct 07, 2021 18:21
£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?
And designed that way in case of traffic queueing back onto the mainline from the roundabout, not by looking at the requirements of predicted traffic flows. Or even current traffic flows, come to that.
That's the thing that struck me too. Slip road traffic queuing back from the junction onto the mainline is best addressed by action at the junction; or, at the very least, by action on the slip road. But no - instead, let's allow the queue to form on lane 1, effectively a very long and possibly dangerous slip road, and compromise the capacity and fundamental effectiveness of our improvement scheme by dropping the lane from the mainline.
We have a history of this in the UK. The last tranche of motorway widening schemes, before Smart Motorways became the done thing, were on the M1, J6a-10 and 25-28. Both added a fourth lane but neither included any junction improvements beyond changes that were necessary to accommodate the new lane. This was despite several junctions along the way being overloaded. The reason for this, as stated at the time, was to “lock in” the benefits of the fourth lane by providing no new capacity to enter or exit the motorway, presumably in the misguided hope that traffic levels on the motorway would remain static. It didn’t work, naturally, and congestion at the junctions is worse than it was before.

The exception was M1 J7 and 8, where there was a material improvement, and CD lanes were added linking the two junctions. That was done on grounds of safety because the two were far too close together. But other quick wins would have been possible and were ignored - providing more than one lane dropping to the M25, for example, or a free flow configuration at J10.

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Re: M4 Junction 3 to 12 Smart Motorway

Post by ChrisH » Fri Oct 08, 2021 09:25

Peter Freeman wrote:
Fri Oct 08, 2021 01:05
Chris5156 wrote:
Thu Oct 07, 2021 18:45
Herned wrote:
Thu Oct 07, 2021 18:21
£800m and J5 is staying as 3 lanes, so widening the entire length except for one section at the busiest end of the route... am I alone in seeing a massive flaw in this plan?
And designed that way in case of traffic queueing back onto the mainline from the roundabout, not by looking at the requirements of predicted traffic flows. Or even current traffic flows, come to that.
That's the thing that struck me too. Slip road traffic queuing back from the junction onto the mainline is best addressed by action at the junction; or, at the very least, by action on the slip road. But no - instead, let's allow the queue to form on lane 1, effectively a very long and possibly dangerous slip road, and compromise the capacity and fundamental effectiveness of our improvement scheme by dropping the lane from the mainline.
It does seem quite perverse logic. If there is a problem of queuing back onto the mainline, then it needs to be addressed by either junction improvements, or longer/wider slip road - not by sabotaging the capacity of the mainline, which was supposed to be the purpose of the scheme!

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Re: M4 Junction 3 to 12 Smart Motorway

Post by WHBM » Fri Oct 08, 2021 10:13

It's not logic, it's excuses.

The issue with M4 J5 is that the existing D3M main carriageway bridges have no hard shoulder either. They date back to when the M4 was built with just two lanes, and a shoulder, and were already minimally ALR'd some time around 1970 when the road changed from a Slough/Maidenhead bypass to a through route to Wales and the West.

Someone seems to have thought at design stage that they could just widen the span for the additional lanes, then later discovered that would never work and it would need new spans, which would cause embarrassment about blowing the original budget. Given the umpteen "consultant studies" done here before things were authorised (Bryn's note above refers) one would have hoped for better. I wonder what intern (charged out at full senior engineer rates, of course) came up with the idea to widen them assymetrically.

Hence the need for excuses

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Re: M4 Junction 3 to 12 Smart Motorway

Post by Herned » Fri Oct 08, 2021 12:29

This seems such a fundamental flaw that I'm surprised it got through planning (well, not really...)

The need for the extra lanes over J5 is not going to go away so I suspect they will need to revisit this fairly soon.

I imagine the long term solution would be to split the lanes into 2+2 for each of the M25 and M4 eb, and then the slip road from J5 can use a flyover to cross the M25-bound lanes and join M4 eb. But I'm not holding my breath

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Re: M4 Junction 3 to 12 Smart Motorway

Post by WHBM » Fri Oct 08, 2021 13:06

Sutton Lane overbridge, just east of J5, appears to be of the same construction as the J5 bridges themselves, so presumably post-tensioned as well and thus considered unalterable without complete replacement. You certainly can't get any more width through there as it stands :

https://www.google.com/maps/@51.4930239 ... 312!8i6656

Old Slade Lane, next to the east, was replaced in situ (no land take) a year or two ago, so it's strange one would be done to suit five lanes but not the other.

https://www.google.com/maps/@51.4941709 ... 384!8i8192

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