M4 Newport Relief Road given go-ahead

[DB617]

It would of course be better to fix our planning process so that every single major project doesn't get stymied and muddied down until its eventual failure, which is essentially the theme of the 2010s for the WG. Perhaps it's just this Government or perhaps it's a broken system.

I suppose I should have said that the Blue Route would be better than nothing at all. Clearly a bottleneck of D2M on an almost all D3M road is a very bad thing. I simply have no faith that SWTRA can handle its devolved roads in a satisfactory way that is on par with Highways England. (we should start by doing away with that awful working name, SWTRA...) Even on an operational level the M4 and other trunk roads and roads within the capital are managed much more poorly than those across the border, for example when gritting and ploughing the M4 during snow, and managing the M4, A470 and Cardiff City VMS. Peid yfed a gyrru! Don't drink and drive! Oh and btw A449 is ar gau.

[roadtester]

Roadchef is worried that the scheme may not allow access to Magor services from the new road.

https://www.southwalesargus.co.uk/news/ ... diversion/

[Bryn666]

The eastern end of the proposed scheme is a total disaster area in need of a major rethink anyway.

[Berk]

Perhaps? But that’s still not a good enough reason for withholding permission for the entire scheme.

That will cause it to be scrapped. Possibly for another 20-30 years. We can not afford to wait that long.

Meanwhile, someone needs to explain why the inspector’s report has been sent to lawyers first, rather than civil servants or ministers.

That seems to be a worrying trend (not least because lawyers aren’t part of the democratic, or planning process).

[Euan]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

[DB617]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

Good point. This was previously 'addressed' by maintaining Aust (so people who were that desperate had somewhere to go), but if they maintain the utterly sh*te M2M terminal roundabout at the Rogiet end of the M48, nobody will use it. Perhaps an offer should be made to allow a new Magor MSA online with the new M4, around the industrial area. As the motorway will already be 'completely destroying' (according to all of its opportunist opponents) the Gwent Levels, there won't be many options for development of an MSA, or fortunately anything else, around the line of the road.

What I still can't understand about that M2M roundabout junction is that in terms of earthworks and disruption it can surely be in no way cheaper than a freeflow arrangement between the two motorways, with a GSJ for the future A471/A449/whatever it will become.

[Berk]

I would say better pass the majority of the scheme and begin construction at the western end, and submit new plans for the eastern terminal junction.

That can then be expanded and modified to incorporate a new service area.

[DB617]

I would say better pass the majority of the scheme and begin construction at the western end, and submit new plans for the eastern terminal junction.

That can then be expanded and modified to incorporate a new service area.

Definitely, if that's possible. I think the potential problems of diversions over the Severn Bridge were shown quite adequately by the chaos at M48 J2 a few days back. Diverting the M4 over a roundabout is pretty rough, as anyone who's ever sat on the SDR in Newport over a night closure (like tonight J24-28 incidentally) can testify to. It just seems rather unnecessary. The M62, M1 and M621 intersect with a complex junction which incorporates a roundabout but handles the major movements increasingly by free flow. There are plenty of interchanges around the country like those which show it's possible, but there's a lack of joined-up thinking and ambition from the WG or the designers, or both. For 1.5bn+ we'd better get something that doesn't later need multi-million pound modifications.

[mikehindsonevans]

Roadchef is worried that the scheme may not allow access to Magor services from the new road.

https://www.southwalesargus.co.uk/news/ ... diversion/

Having suffered the suboptimal layout and facilities at Magor over decades (even going so far as to actively avoid the site) I would regard this as an improvement for the nation.

[mikehindsonevans]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

This gap arose when the M4 was switched to the SSC. We always take the old bridge and plan a break at Severn View at Aust (which is ironic naming, given that the "new" 1996 Aust MSA site is down a slope and half-a-mile from the river and the wonderful view from the original (1966) service area building (despite its odd layout at the time).

Nothing that a "Chepstow and Services" sign couldn't cure, unless the plans eliminate access to the M48.

[gepree68]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

Wouldn't this original plan be a good solution to the problem?

[Euan]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

M4 J23 and J23a.jpg
Wouldn't this original plan be a good solution to the problem?

Yes I think that would have worked well. In that plan the services look easily accessible from every route.

[A9NWIL]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

M4 J23 and J23a.jpg
Wouldn't this original plan be a good solution to the problem?

The trouble with that is there still wouldnt be freeflow from the M48 WB to the M4 WB, there is freeflow M48 EB to M4 EB and M4 WB to M48 WB.

I think the roundabout is good but it shouldnt be a substitute for M48 WB to the M4 WB if not using the services.
Perhaps they should build it so that the M48's carriageways go either side of the M4, so the M48 becomes the weaving area. The roundabout in that diagram should act as a way to turn around, join the services or get from the M48 back to the M4 after using the services.

[Berk]

Not every motorway had every movement, though. If you’re entering Wales on the M48, you’ve made a decision to do so.

Unless you’re trying to access Chepstow (or are a Sabristo), I can’t think of any real reason to do so.

[Euan]

Yes, the vast majority of traffic crossing the Severn bridges will use the M4 rather than the M48 and would not have an interrupted flow. The M48 is essentially a bypassed "local access" motorway for Chepstow. However if the M4 across the Severn is closed you might run into problems if there is no free flow at J23a.

[DB617]

The ex-M4 won't be going away, don't forget. That's not going to be reduced any smaller than D2M at a possible 50mph permanent limit. Should be acceptable for a temporary emergency diversion, as long as free flow is available in any way from M48 WB. After all, some of us have been living with said road for years and 50mph average speed is good going.

[Euan]

The ex-M4 won't be going away, don't forget. That's not going to be reduced any smaller than D2M at a possible 50mph permanent limit. Should be acceptable for a temporary emergency diversion, as long as free flow is available in any way from M48 WB. After all, some of us have been living with said road for years and 50mph average speed is good going.

I never realised the intention was to reroute the M4 along the relief road, although looking at the Magor plans the fact that the relief road is set to be the new through road would suggest that is the case. I wonder what the plans are for the existing northern bypass, number-wise.

[gepree68]

The trouble with that is there still wouldnt be freeflow from the M48 WB to the M4 WB, there is freeflow M48 EB to M4 EB and M4 WB to M48 WB.

Really? I thought the map would look like the above plan, with existing light blue roads still there.

Does anyone have a full version of the original plan for changes to this M4/M48 junction?

Or can anyone confirm whether the light blue lines (on my map) would be included in the proposed layout?

[betweenmways]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

M4 J23 and J23a.jpg
Wouldn't this original plan be a good solution to the problem?

OK for the services, but not so good for Chepstow (et al) to Bristol traffic when the M48 is closed. Rush hour traffic on the Magor junction is already pretty horrible (people doing essentially U turns) when the M48 bridge is closed, but would it really go around the services junction to get on the M4?

[A9NWIL]

If the relief road does not come with adequate access to Magor Services there would be a 48 mile gap along the M4 between Cardiff Gate Services and Leigh Delamere Services which exceeds the DfT recommended maximum gap between services by about 20 miles, although having said that Leigh Delamere to Magor is already 39 miles. The assessment in the article excludes the nearest adjacent service areas on the M5 though.

M4 J23 and J23a.jpg
Wouldn't this original plan be a good solution to the problem?

OK for the services, but not so good for Chepstow (et al) to Bristol traffic when the M48 is closed. Rush hour traffic on the Magor junction is already pretty horrible (people doing essentially U turns) when the M48 bridge is closed, but would it really go around the services junction to get on the M4?

In that case you would also need M48WB to M4EB and M4WB to M48EB. its looking like you may as well have full freeflow between the two motorways in all directions! As you only need two more for a full set!