M4 Junction 3 to 12 Smart Motorway

[DavidBrown]

What's the latest in terms of actual work starting on this? Older posts on this thread say Autumn 2017, but when I went up that way at the end of October, there was absolutely no sign of anything happening.

[ManomayLR]

I don’t really know what’s going on; they said they’d start construction in March but not much appears to be going on.

[ManomayLR]

For the MS4s, where there are already MS4s will they be replaced or will the existing MS4s be modified for VSL?

[WHBM]

What's the latest in terms of actual work starting on this? Older posts on this thread say Autumn 2017, but when I went up that way at the end of October, there was absolutely no sign of anything happening.

Curiously, the works I described above 8 months ago on the roundabout at J5 have been finished and demobilised, with hardly anything seeming to have been achieved. They have to do significant work here because the motorway over the roundabout is on an embankment, just 3 lanes without any hard shoulder.

[ManomayLR]

I know I've said this before but I'll say it again, the "new" Smart Motorway standards, using MS4s instead of gantries with signals above each lane and with the emergency refuge every 2.5km is so horribly bad IMO.

I also hope they're going to re-allocate the lanes appropriately coming eastbound towards 4a, so at least two (preferably three) lanes are available for the M25-bound traffic. I wonder if these lanes will vary according to time-of-day / how busy this section is.

And yeah, if the bridges / underpasses are going to be replaced, PLEASE HA can you future-proof these for 4 lanes plus Hard Shoulder?

Old quote- but a response. The MS4s are the best things SMART motorways could ever have. We don’t need signals above each lane, it’s silly and causes visual nuisance. Fitting lane control at J4A is unlikely because the direction signs will also have to be variable but it is possible. Future-proofing for D4M is a must so we can expand to D5ALR if we need it.

[BOH]

For the MS4s, where there are already MS4s will they be replaced or will the existing MS4s be modified for VSL?

What are "MS4s" please?

[c2R]

For the MS4s, where there are already MS4s will they be replaced or will the existing MS4s be modified for VSL?

What are "MS4s" please?

From our wiki:

[ManomayLR]

For the MS4s, where there are already MS4s will they be replaced or will the existing MS4s be modified for VSL?

What are "MS4s" please?

From our wiki:

Not to boast, but I took that! It was on the M1 j39-42 SMART motorway. the incident was fairly minor, just a stranded vehicle, but in a live lane which had to be closed. Caused no congestion and no problems, so I don't know why people are complaining about the ERAs on the M4:

www.msn.com/en-gb/cars/news/£862m-m4-motorway-upgrades-unlikely-to-include-emergency-rest-areas/ar-BBKp7On?ocid=spartandhp
I read this and I thought, well the refuge areas would be orange! how can they not be missed!

[ChrisH]

I emailed HE with a list of questions about this project, which is about to kick off in earnest.

I won't post the full exchange but the summary is:

- Street lighting currently exists everywhere except J8/9-10; and this will not change with Smart Motorway.
- ERAs will be placed every 1.8km on average although they are considering whether extra could be provided on the M4.
- Noise barriers will be erected along an extra 10km of the route. (I actually asked about the safety fencing along the edge of the carriageway but this wasn't answered.)
- Bridges which need to be widened (which is all of them between Slough and Maidenhead) will only have the additional lane of width added, with no future proofing.
- Through junction running at all junctions except J10 and J4b, because they have free-flow exit slips with two lanes on.
- J4b will eventually have two lanes exiting for M25 and three for M4, but only with the full scheme and no interim restriping will be carried out.

[sotonsteve]

Keeping the street lighting where it is present is a nonsense. Whilst lighting is justified around the J3 to J8/9 section, the J10-12 section of lighting is wasteful and unnecessary. In lots of other parts of the country, lighting like the J10-12 section is being removed. I think they're only keeping it the way it is to avoid rocking the boat, rather than doing what is right.

[Chris5156]

J4b will eventually have two lanes exiting for M25 and three for M4, but only with the full scheme and no interim restriping will be carried out.

That's interesting. The M4 currently has three lanes through 4B and that is always (in my experience) more than required while the exits for the M25 are packed. I wonder whether HE could afford to be more daring and stripe it with three lanes exiting and two continuing through.

I don't know whether the factor preventing that is the traffic counts supporting a need for three lanes through the junction, or just conservatism about how many lanes should be on the mainline of a route like the M4.

[Bryn666]

Keeping the street lighting where it is present is a nonsense. Whilst lighting is justified around the J3 to J8/9 section, the J10-12 section of lighting is wasteful and unnecessary. In lots of other parts of the country, lighting like the J10-12 section is being removed. I think they're only keeping it the way it is to avoid rocking the boat, rather than doing what is right.

The process in accordance with guidance laid out in IAN 167/12 http://www.standardsforhighways.co.uk/h ... ian167.pdf will have been undertaken and presumably that has determined it is necessary to keep it.

[ManomayLR]

No restriping at 4b is a huge farce. Even if the junctions have ALR they must add an extra lane for the M25!!!

[A303Chris]

Dates for exhibitions for first section of works between J8/9 and J12 have been announced together with a programme of works and it is all on the scheme page here

Basically J8/9 to 10 will be done between September this year and May 2020,

J10 to J12 May 2020 to February 2022

J8/9 to J3 Summer/autumn 2019 to March 2022

So either way 31/2 years of chaos.

[WHBM]

The preliminary works done on the bridges at J5 have been cleared away for over 12 months now, although (any of you on the project reading this) a lot of the barriers and edge protection were left behind, and surprisingly nobody has helped themselves to it. The area where the cabins were has become substantially weed-overgrown in a notably short time.

[ChrisH]

These works have been going on for around 5 months now. Some interesting progress:

Between J8/9 and J10 the central barrier has been removed, and about 2.5 miles of concrete barrier has been installed. I've been interested to see that the footings and foundations are all concrete, with seemingly no steel inserts. In the context of hostile vehicle mitigation where we use deep steel foundations, it seems surprising that nothing like this is done for smart motorway barriers. There is also a section of removable barrier installed, which presumably is for emergency turnarounds.

Part of the section near the installed concrete barrier has had its carriageway laid and striped, and the temporary metal barrier removed. This makes the carriageway feel a lot wider already. It's hard to see what more there will be to do, once the central barrier is installed. I don't think there is any widening on the near side to do?

An enormous works compound adjacent to the eastbound carriageway just after J10 has been put up, with a full "Works Unit Only" exit and whole fields appropriated. Also full vegetation clearance within the slip roads at J10 which I cannot understand the purpose of.

A lot of vegetation clearing along the edge of the motorway has revealed that the highway boundary, in most places, is about 10m back from the carriageway. I think it is a big shame that discontinuous hard shoulders are not being installed where there is no need for land acquisition.

East of J8/9, on the old section of M4 which was widened from D2M back in the 1970s, it's clear to see why this widening will be so tricky. The narrow lanes now extend to J7 but this only buys about 1m of space at all the bridges - obviously not enough to work on, and neither is it enough space to replace the central barrier in the (relatively) painless way done to the west.

[A303Chris]

An enormous works compound adjacent to the eastbound carriageway just after J10 has been put up, with a full "Works Unit Only" exit and whole fields appropriated. Also full vegetation clearance within the slip roads at J10 which I cannot understand the purpose of.

Chris funny you should put this up as I have some photos which I have added to the library of the signage and slip roads into this large works compound which has taken over three fields. As well as the access directly to and from the eastbound M4 there is also an access from the A321 Twyford Road and when out on my bike at the weekend I will take some photos of this.

I have never seen a works compound access directly from the main carriageway and the signing is weird as well, blue signs for the advanced directions signs at 1/2 mile and at the start of the slip, but red signs at the slip road. Thought they would all be red as they are for a restricted slip road.

When I have been involved on motorway schemes the compounds have been adjacent to junctions and you used the existing infrastructure to get on and of the motorway

Given the design of the slips and the access road from the A321, I wonder if these will be used for an eastbound MSA when the works are finished. Given the size of the compound it must be the site HQ for the full length of the works.

Half Mile ADS

ADS at start of slip road

Start of slip road

Slip road signage

I do have another photo which wont up load for some reason which shows a large red sign on the left of the slip road with the wording "BBVJV TRAFFIC ONLY"

Have to say I took these on the way to Stamford Bridge as I wasn't driving with mates saying you're weird.

[ChrisH]

Another six weeks on from my last update:

- Now about 4 miles of concrete central barrier between J8/9 and 10, with several more miles nearly ready

- Traffic management there, and west of J10, is now switching to giving more space to work on the nearside (Not sure why west of J10 doesn't have its central barrier replaced first)

- The land inside J10 is being prepared for yet more worksite space. It's hard to imagine how the contractors could need any more land after the vast space they have set up just east of that junction?!

- Works east of J8/9 are still progressing slowly with bridge works - it's easy to see how this will take a lot longer, as the contractors need to widen all the structures first before installing the concrete central barrier and fourth running lane

[ChrisH]

Works are well underway on almost all of the M4 junctions 3 to 12 now. From J3 to J4B a 50mph speed limit westbound now applies with initial works to start removing the central barrier. (Eastbound of course is already limited in speed)

Between the M25 and Slough there is a small stretch not being worked on, except for 11 bridges which need demolishing. The first of these was done over a weekend at the end of September. It does seem unfortunate that there have to be full weekend closures of of the M4 for almost all of these demolitions, which will lead to a lot of disruption in the local area. Certainly the A404 and M40 were extremely busy on the weekend of the first closure.

West of J8/9 the concrete central barrier has now been installed all the way to J12. A lot of verge works are underway including vegetation clearance and installing what must be nuclear bunkers disguised as gantries - sheathed in astonishing amounts of concrete, even for a like-for-like replacement of MS4 gantries - which previously had no concrete footing at all and yet seemed to survive OK.

HE's newsletter from the summer suggests that this western section could open in 2021, but I can't see why it's going to take more than a full year to tidy up the nearside verge, install some barriers and laybys and commission the comms and road management. Maybe I'm missing something

Also interesting to see that different Smart Motorway projects seem to be built in quite different ways: the M23 around Gatwick and the M20 in Kent have had entire verges ripped up with new retaining walls built, different spec gantries, and yet still no concrete central barrier. I'm surprised that there isn't more of a "kit of parts" or common approach to constructing these schemes.

[jackal]

Also interesting to see that different Smart Motorway projects seem to be built in quite different ways: the M23 around Gatwick and the M20 in Kent have had entire verges ripped up with new retaining walls built, different spec gantries, and yet still no concrete central barrier. I'm surprised that there isn't more of a "kit of parts" or common approach to constructing these schemes.

HE hope to develop such a modular approach for RIS2 smart motorways. At the moment each scheme is designed separately.