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CrackersA361 wrote:I am staggered by the J23 design. I would love to meet the person, or group of people that sat round a table and said "yes, let's have the M48 terminate on a roundabout - what could possibly go wrong?"
It's almost as if they don't want the new M4 section to work - the reason it's being built is to provide relief to the existing road! What's the point in building it if you're just going to cock up the old road, forcing everyone to just move a few miles to the south with all of the congestion that will entail?
It's beyond belief.
The question to ask is how much life is left on the original Severn Bridge, and what plans are there to replace that bridge when it becomes life-expired. My understanding is that there isn't much life left in the bridge (compare with the Forth Road Bridge of the same era). If the bridge is not replaced, the roundabout makes more sense, especially if it allows a simpler arrangement for the new main line M4.
I think closing the original Severn bridge would be a great mistake, but I understand the need for projects to stack up in cost benefit terms and can see how this sort of thought process might lead to the design that is proposed.
Cheers,
Simon
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That's a good point Simon re the life in the original Severn Bridge - I'd not expect it to be replaced on current needs, but there is always the potential for a tidal barrage replacement, perhaps even run the GWML over the barrage rather than in the current maintenance liability of a tunnel
Associated British Ports have expressed concern that the plans will have an adverse impact on Newport Docks, and feel the route taking the road further north should have been chosen instead:
The M48 can end at a roundabout, sure, but why have the Newport Northern bypass so poorly plugged in? That will have double the eastbound traffic of the M48, and 1.5 times the westbound.
I also note that M48 traffic will increase under the scheme - probably as more NNB traffic would use it, to try and avoid the crappy junction.
"“Peace, commerce and honest friendship with all nations" Thomas Jefferson
si404 wrote:The M48 can end at a roundabout, sure, but why have the Newport Northern bypass so poorly plugged in? That will have double the eastbound traffic of the M48, and 1.5 times the westbound.
I also note that M48 traffic will increase under the scheme - probably as more NNB traffic would use it, to try and avoid the crappy junction.
Yes, my concern is much less to do with links between the M4 and M48, and much more to do with links between the Second Severn Crossing and the existing Newport Bypass.
End the M48 at a roundabout if you must, but a couple of free-flow sliproads on to the former M4 would be an obvious improvement.
si404 wrote:The M48 can end at a roundabout, sure, but why have the Newport Northern bypass so poorly plugged in? That will have double the eastbound traffic of the M48, and 1.5 times the westbound.
I also note that M48 traffic will increase under the scheme - probably as more NNB traffic would use it, to try and avoid the crappy junction.
Yes, my concern is much less to do with links between the M4 and M48, and much more to do with links between the Second Severn Crossing and the existing Newport Bypass.
End the M48 at a roundabout if you must, but a couple of free-flow sliproads on to the former M4 would be an obvious improvement.
Very difficult to argue with this, Chris. Northern Newport and the Gwent valleys are sufficiently big enough catchment area to justify a free-flow link to the eastbound M4, as well as towards Cardiff.
Cheers,
Simon
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fras wrote:I see the usual BANANA croakers are croaking away loudly. Why DO we pander to these bovinely stupid people.
Because we live in a democracy (of sorts).
Education makes the wise slightly wiser, but it makes the fool vastly more dangerous. N. Taleb We tend to demand impossible standards of proof from our opponents but accept any old rubbish to support our beliefs. The human paradox that is common sense The Backfire Effect
M4Simon wrote:
The question to ask is how much life is left on the original Severn Bridge, and what plans are there to replace that bridge when it becomes life-expired. My understanding is that there isn't much life left in the bridge (compare with the Forth Road Bridge of the same era). If the bridge is not replaced, the roundabout makes more sense, especially if it allows a simpler arrangement for the new main line M4.
I think closing the original Severn bridge would be a great mistake, but I understand the need for projects to stack up in cost benefit terms and can see how this sort of thought process might lead to the design that is proposed.
Cheers,
Simon
A very good question posed. What is the plan long term for the original crossing?
Whilst strategically for the national road network it is no longer significant, however the fact that cyclists, mopeds and pedestrians can cross it would mean it is an important local asset.
Sou'wester wrote:
A very good question posed. What is the plan long term for the original crossing?
Whilst strategically for the national road network it is no longer significant, however the fact that cyclists, mopeds and pedestrians can cross it would mean it is an important local asset.
If you want to get from the Bristol area to Chepstow, or the Forest of Dean, there's no alternative. They'd have to build an extra junction on the M4 to allow people to double back. (And I know someone who commutes from Chepstow to Bristol, so it's not a theoretical consideration.)
And as you say, it needs to be maintained as a cycle and pedestrian crossing. I've walked across it myself, though I can't say I saw a lot of other pedestrians.
Brock wrote:If you want to get from the Bristol area to Chepstow, or the Forest of Dean, there's no alternative. They'd have to build an extra junction on the M4 to allow people to double back. (And I know someone who commutes from Chepstow to Bristol, so it's not a theoretical consideration.)
The planned junction is full access
"“Peace, commerce and honest friendship with all nations" Thomas Jefferson
Brock wrote:If you want to get from the Bristol area to Chepstow, or the Forest of Dean, there's no alternative. They'd have to build an extra junction on the M4 to allow people to double back. (And I know someone who commutes from Chepstow to Bristol, so it's not a theoretical consideration.)
Many people commute from Chepstow to Bristol. Until he retired, my dad used to commute from Tutshill to Stroud. My mum worked with someone who commuted from Bristol to Cinderford.
Add to these people the fact that Chepstow, Monmouth, the Wye Valley and Forest of Dean are significant tourist destinations, then access from the M4 to Chepstow is important not just for commuters and holidaymakers, but also the local economy.
This might seem crazy, but this seems like a cheap and easy way to remove that planned roundabout bottleneck.
Yes, there is no junction between the M4 and M48. I don't think such a junction is necessary.
Traffic from the North Newport area to Bristol can travel via the Severn Bridge; Chepstow to western Wales can go via the old M4 (to be reclassified as M48). Both traffic flows are low compared to what would be on the M4, and the M48 should manage them with no problem. And this actually saves money relative to the official plan.
Is there any reason a M4/M48 junction is necessary?
6637 wrote:Yes, there is no junction between the M4 and M48. I don't think such a junction is necessary.
Traffic from the North Newport area to Bristol can travel via the Severn Bridge; Chepstow to western Wales can go via the old M4 (to be reclassified as M48). Both traffic flows are low compared to what would be on the M4, and the M48 should manage them with no problem. And this actually saves money relative to the official plan.
Is there any reason a M4/M48 junction is necessary?
The biggest problem that I can see with that plan is that if one of the bridges is closed, it makes it more difficult to shepherd traffic onto the other bridge if there is no link between them, without sending all the traffic through Magwyr, which would be totally unsuitable.
6637 wrote:Yes, there is no junction between the M4 and M48. I don't think such a junction is necessary.
Traffic from the North Newport area to Bristol can travel via the Severn Bridge; Chepstow to western Wales can go via the old M4 (to be reclassified as M48). Both traffic flows are low compared to what would be on the M4, and the M48 should manage them with no problem. And this actually saves money relative to the official plan.
Is there any reason a M4/M48 junction is necessary?
The biggest problem that I can see with that plan is that if one of the bridges is closed, it makes it more difficult to shepherd traffic onto the other bridge if there is no link between them, without sending all the traffic through Magwyr, which would be totally unsuitable.
If a connection between the motorways must be retained, couldn't something like this be done?
It is essentially the same as the planned design, with the change being free-flow from M48 to the Newport north by-pass. It doesn't need to even be as sophisticated as a trumpet (have a roundabout or dumbbell there instead) - as others have suggested, traffic for the northern side of Newport can be directed over the original M48, meaning movements between the two motorways are reduced.
I can see a cheap solution now being a false economy later on. Will we end up with another Catthorpe where it'll cost a fortune to put right? These are strategic roads we're talking about so links between them are far more important than a junction with the local B road. By all means have a junction with the B road but not at the expense of the M48 and existing M4.
How would you like your grade separations, Sir? Big and complex.
mapboy wrote:as others have suggested, traffic for the northern side of Newport can be directed over the original M48, meaning movements between the two motorways are reduced.
So the 500,000 people who will live north of the new M4 will be forced over the crumbling original Severn Bridge and forced to travel two miles further than they currently do? Good luck selling that!
Just out of interest, how many times has the original Severn Bridge had to take the full flow because of a closure of the Second Severn Crossing? I can't find the answer but I have a feeling this has happened at most just once or twice?
Still don't think the junction should be hobbled in this way, though.
