M4 Junction 3 to 12 Smart Motorway

[mathmo]

I went to the consultation this week (given I commute along the M4 here).

Most of the information was already available online. They also had some diagrams that aren't online showing locations of gantries, refuge areas, etc, though the number of staff surrounding them meant I didn't feel comfortable trying to get pictures (sorry). What I saw (I only looked at a small part) seemed reasonably sensible, though the refuge areas are really quite a long way apart.

I was interested in what's happening between junctions 5 and 4b because the information online isn't very clear. Apparently it will be four lanes under the Sutton Lane bridge just east of J5, then widening to five lanes (no hard shoulder) eastbound only, with two lanes for the M25. I think this will be quite a tight merge from J5. It feels like they are trying (understandly) to avoid a very expensive replacement of the bridge here (which is quite heavily used so I guess it would have to be replaced offline). Westbound they claimed the traffic flows did not require five lanes so it will be four lanes plus hard shoulder as today, but with lane 1 carrying on through J5 rather than being dropped.

As far as construction goes, there is no contractor involved yet so nothing is certain, but they expect to start with J12-8/9. Apparently the difficulty in getting possessions for the Slough-Windsor railway means that this will likely slow down the eastern section. Unsurprisingly, the bridge work will take much longer than the other changes required.

[mathmo]

The consultation report was released on the 30th March:
https://www.gov.uk/government/uploads/s ... Report.pdf

There's almost 250 pages and it doesn't look like much has changed except a few minor details.

[M4 Cardiff]

Let me guess, they want to build it in one go so there will be 35 miles of SPECS enforced 50 for about 18 months - 2 years????

[Norfolktolancashire]

Let me guess, they want to build it in one go so there will be 35 miles of SPECS enforced 50 for about 18 months - 2 years????

The 50mph will reduce air pollution now that the UK is being held to account for by the EU, and when completed the road can have a dedicated "diesel lane" that will keep all diesel vehicles at 50mph or less. I would put a winking smiley here if it wasn't a potential idea!

[M4 Cardiff]

Let me guess, they want to build it in one go so there will be 35 miles of SPECS enforced 50 for about 18 months - 2 years????

The 50mph will reduce air pollution now that the UK is being held to account for by the EU, and when completed the road can have a dedicated "diesel lane" that will keep all diesel vehicles at 50mph or less. I would put a winking smiley here if it wasn't a potential idea!

HGVs in left lane only! that would make things flow a lot better (except at junctions)

I still maintain though, that somewhere in the HA/ DoT there is a plan to reduce the motorway limit permanently to 50, and that by doing really long stretches under SPECS enforcement at 50 is merely 'softening us up' for it. I'm all for keeping our roadworkers and contractors safe, but do they really need to work on 30+ miles at a time?

Just like I'm totally convinced that when the ID requirements for buying tobacco / alcohol were raised from 21 to 25, it was more to do with softening up the nation's young to carrying ID cards in the run up to Labour's ID card policy at the time, rather than actually having anything to do with stopping underage consumption.

[mathmo]

They've never said they will work on the whole stretch at once. In fact, when I asked at the consultation they reckoned work would probably be done in two halves with J8/9-12 first.

[Phil]

They've never said they will work on the whole stretch at once. In fact, when I asked at the consultation they reckoned work would probably be done in two halves with J8/9-12 first.

West of Maidenhead though the works will be relatively minor though - it has a continuous hard shoulder so all that needs doing is a bit of narrowing of the central reserve plus putting up all the electronic gizmos 'Smart Motorways' need and the construction of a few 'Emergency Refuge Areas' (which I bet will be put even further apart than the recent M25 ones).

East of Maidenhead however there is plenty of bridge work needed plus embankment widening etc so it will take longer. Thus if the plan is to ave the whole thing finished at approximately the same time then you need to be starting with the most difficult bit closest to London, with the bit closer to Reading kicking off later. Alternatively you start work on the entire length at the same time - with the aim that they will be complete for when the Smart Motorway installers will have finished doing the section onwards so they can simply carry on Eastwards without a break.

[Jeni]

West of Maidenhead though the works will be relatively minor though - it has a continuous hard shoulder so all that needs doing is a bit of narrowing of the central reserve plus putting up all the electronic gizmos 'Smart Motorways' need and the construction of a few 'Emergency Refuge Areas' (which I bet will be put even further apart than the recent M25 ones).

You call that minor work, but it will still be 3 years of 50mph and narrow lanes judging by the construction of every other smart motorway!

[XC70]

Interestingly, when I went to the exhibition on the M1 J28-J31, they said that there would be all MS4's and that gantries were expensive to put up and required heavy footings. Now that it is getting on for completion, they are actually installing gantries every 2km, with plenty of MS4 panels inbetween (I think maybe every 500m). Perhaps the idea of MS4's on their own has been quietly shelved?

[WHBM]

I too am surprised by just how little work is actually achieved in all the years of work for "Smart Motorways". Particularly the ALR M25 J23-27 bit.

gantries were expensive to put up and required heavy footings.

OK, muck out, concrete in. Normal small civils stuff. What can be difficult about that ?

construction of a few 'Emergency Refuge Areas' (which I bet will be put even further apart than the recent M25 ones).

These on the M25 J23-27 have become the new rest areas for European HGVs who have reached their tacho hours limit by driving beyond South Mimms. They completely fill the little layby, you wouldn't get a car in behind, and when they leave there is no acceleration space and being LHD they depend on a little mirror view. Some have been sited on left hand bends, further restricting the view, because nobody envisaged working like this. I believe because of the hazard, if the police come upon these they do not take time taking details for someone who suddenly has difficulty with English, but just shoo them on.

I do notice on the London radio traffic reports it's now almost daily there are reports of delays on this section "due to a broken down vehicle". I actually wonder, with all the fuss of signalling and merging, deploying the crash cushion vehicle, etc, whether capacity past a breakdown on 4-lane ALR is actually less than 3 lanes and a hard shoulder with a breakdown on it.

The minimal number of refuge areas is stupid. There are intermediate points with level land alongside where it would have been no engineering difficulty to build extra ones, yet they were not done.

[RichardA35]

I too am surprised by just how little work is actually achieved in all the years of work for "Smart Motorways". Particularly the ALR M25 J23-27 bit.

gantries were expensive to put up and required heavy footings.

OK, muck out, concrete in. Normal small civils stuff. What can be difficult about that ?

Generally need some piles or some other mechanism to mobilise against uplift caused by designing for HGV impact above carriageway - but that aside they are generally quite a simple activity.
Without widening going on, it's the retaining wall behind them that will be the unique or trickier element for this glorified technology upgrade.

[XC70]

I too am surprised by just how little work is actually achieved in all the years of work for "Smart Motorways". Particularly the ALR M25 J23-27 bit.

gantries were expensive to put up and required heavy footings.

OK, muck out, concrete in. Normal small civils stuff. What can be difficult about that ?

Generally need some piles or some other mechanism to mobilise against uplift caused by designing for HGV impact above carriageway - but that aside they are generally quite a simple activity.
Without widening going on, it's the retaining wall behind them that will be the unique or trickier element for this glorified technology upgrade.

And after watching the works happen and watching the massive footings go in for the cantilevered large MS4 panels I also think that what I was told was a load of BS. The gantry footings actually seemed to be smaller than for the MS4's and the gantries span the whole carriageway but seem quite lightweight and slender. I assume they must be easier to design foundations for as they are supported at both ends...

[M4 Cardiff]

Generally need some piles or some other mechanism to mobilise against uplift caused by designing for HGV impact above carriageway - but that aside they are generally quite a simple activity.
Without widening going on, it's the retaining wall behind them that will be the unique or trickier element for this glorified technology upgrade.

I know they pile a lot of them - I worked on a site with some cable percussion drillers once who had just come off a job doing pile design boreholes for gantries (and SPECS bases also IIRC) on the M4.

[Phil]

West of Maidenhead though the works will be relatively minor though - it has a continuous hard shoulder so all that needs doing is a bit of narrowing of the central reserve plus putting up all the electronic gizmos 'Smart Motorways' need and the construction of a few 'Emergency Refuge Areas' (which I bet will be put even further apart than the recent M25 ones).

You call that minor work, but it will still be 3 years of 50mph and narrow lanes judging by the construction of every other smart motorway!

Note I said relatively - and in this case the comparison is between Smart Motorway works in one direction an Smart Motorway works PLUS widening / bridge reconstruction works in the other

[A303Chris]

Highways Press release, summary details below , full details here

Opportunity for public to register interest in M4 smart motorway proposal

Members of the public are now able to make representations on the M4 junctions 3 to 12 smart motorway scheme in Berkshire and west London following the acceptance on 27 April 2015 of the application for a Development Consent Order (DCO) by the Planning Inspectorate.

Any representations giving notice of any interest in, or objection to, the application must be made on the Planning Inspectorate’s Registration and Relevant Representation Form which can be accessed and completed online by following the instructions on the National Infrastructure Planning website. Paper copies of the forms can be accessed by calling 0303 444 5000.

Representations must be received by the Planning Inspectorate by 11:59pm on 3 July 2015. Representations will be made public by the Planning Inspectorate.

I will make a representation basically on the folly of building new structures between J8/9 and J5 where the road was rapid widened in 1972 from D2 with HS to D3 with intermittent HS, not included over under structures to D$ ALR with out HS. My view is if you are doing on this work make this extremely busy section D4 with HS and ALR J12 to J8/9 only.

[ChrisH]

I will make a representation basically on the folly of building new structures between J8/9 and J5 where the road was rapid widened in 1972 from D2 with HS to D3 with intermittent HS, not included over under structures to D$ ALR with out HS. My view is if you are doing on this work make this extremely busy section D4 with HS and ALR J12 to J8/9 only.

I made the same point in the first consultation - that new structures should be built wide enough for D4M for a (presumably) low marginal cost. When I read the consultation report I think a grand total of three people had made the same point. I wonder if the third person was also called Chris

[Peter Freeman]

I will make a representation basically on the folly of building new structures between J8/9 and J5 where the road was rapid widened in 1972 from D2 with HS to D3 with intermittent HS, not included over under structures to D4 ALR with out HS. My view is if you are doing on this work make this extremely busy section D4 with HS and ALR J12 to J8/9 only.

My view is that if you are rebuilding these structures, then, assuming there's sufficient reserve width, make this extremely busy section D5 ALR. J12 to J8/9 can be D4 ALR, using existing structures. ALR all the way would provide a more consistent feeling, even though the width would vary and there would be lane drops.

[Chris5156]

I will make a representation basically on the folly of building new structures between J8/9 and J5 where the road was rapid widened in 1972 from D2 with HS to D3 with intermittent HS, not included over under structures to D$ ALR with out HS. My view is if you are doing on this work make this extremely busy section D4 with HS and ALR J12 to J8/9 only.

I made the same point in the first consultation - that new structures should be built wide enough for D4M for a (presumably) low marginal cost. When I read the consultation report I think a grand total of three people had made the same point. I wonder if the third person was also called Chris

That may well have been the case...

[A303Chris]

Interesting update on this one. As the M4 was rapid widened between junction 8/9 and 5 in 1971 prior to the opening of the road westwards past Reading, all the structures over or under the motorway apart from at junction 6 have no hard shoulder. As a result for the smart motorway all new bridges are being built albeit without any hard shoulders. As a result planning permission is required as the new bridges (especially overbridges) will be adjacent to the existing and outside the highway land.

As the M4 is part of the strategic network the planning permission will be determined by the National Infrastructure Unit at the Planning Inspectorate. On September 3rd in Maidenhead there is the Inspectors first preliminary meeting which is open to all Local Authorties along the route and the public. The details are at the bottom of the DfT scheme page here.

If you click on the rule 6 letter link you will see the Inspectors letter and issues he wants to look at before determining the application and also all the dates submissions are required. I will be attending representing my Authority.

With Annex B of the Rule 6 letter is a list of the matters to be discussed and section 4 Impact on Road Users is very interesting

4 Impact on Road Users

I. Whether the introduction of all lane running would undermine safety of traffic using the motorway

ii. Whether the introduction of emergency refuge areas at 2.5km intervals would secure the safety of users of the motorway in the event of breakdown or other emergency

iii. Whether the scheme would increase flows on road in the surrounding area to the detriment of road safety

iv. Whether the scheme would impact upon the safety or convenience of non motorised forms of travel.

Points I and ii are what many of us have been saying on these forumns and I recommend as many of us write to the Inspector enhancing thee views.

In the preceding section there is a note , does the design meet the requirements for good design. My view has always been if you are going to build 10 miles of new structures do it properly and add a hard shoulder.

Hopefully the Inspector will see the folly of such improvements

[Daveoc64]

Points I and ii are what many of us have been saying on these forumns and I recommend as many of us write to the Inspector enhancing thee views.

Shouldn't those points be decided on the basis of actual evidence, most of which suggests that "Smart Motorways" projects have improved safety and road performance?

With so many similar schemes in use for several years (including on the M4 here near Bristol), it's getting harder to argue that the lack of a hard shoulder is a real problem.

Granted, ALR hasn't been around for anywhere near as long as hard shoulder running has.