A358 Taunton to Southfields

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jackal
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A358 Taunton to Southfields

Post by jackal » Tue Mar 28, 2017 12:07

This scheme has now opened for consultation: https://highwaysengland.citizenspace.co ... uthfields/

HE seem to be embarrassed about the junction designs and haven't included them in the brochure, but they're in the Technical Appraisal Report:
Option 8 with NFS - Copy.jpg
It's far worse than the proposal from a decade or so ago. There's no GSJ at Southfields; the widened road will plug into the existing roundabout. Worse, instead of a freeflow junction at the M5, there will be roundabout GSJ, which according to the TAR will also serve as 'a new access junction for development' :(
Last edited by jackal on Tue Mar 28, 2017 17:26, edited 2 times in total.

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jackal
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Re: A358 Taunton to Southfields

Post by jackal » Tue Mar 28, 2017 13:12

As you can see here, the three other options considered in the TAR all had freeflow to/from the M5 Exeter.
Option 1 with NFS - Copy.jpg
Option 2A 2B - Copy.jpg
Option 8 with J25 - Copy.jpg
Unsurprisingly, they all had higher cost-benefit ratios than the proposed option :roll:

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Re: A358 Taunton to Southfields

Post by DavidBrown » Tue Mar 28, 2017 17:16

Well I've filled in my questionnaire and tore them apart on the junction designs. Quite how they think that the local connections are anything like acceptable I don't know - the main road into Taunton from the south will all of a sudden become a B road that passes several schools and is already congested at the best of times. And any Taunton traffic from the A303 will still have to go through Henlade, making the seperately proposed M5 J25 scheme utterly useless.

And as for Southfields - jeez. :bang:

Fluid Dynamics
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Re: A358 Taunton to Southfields

Post by Fluid Dynamics » Tue Mar 28, 2017 18:21

I presume they've left Southfield out, to be sorted when the Ilminster bypass is dualled?

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jackal
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Re: A358 Taunton to Southfields

Post by jackal » Tue Mar 28, 2017 18:29

I think so. Highways England are assuming the Ilminster bypass widening will be open around five years after this scheme, so I don't think Southfields is a huge problem. The connection to the M5, and as David says the local access, are the dealbreakers as they will be permanent.

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Re: A358 Taunton to Southfields

Post by crowntown100 » Wed Mar 29, 2017 21:56

Oh dear... Well, all of the options that Jackal has placed are better than the one taken forward. Hopefully this isn't a repeat of Chichester in the making...

Shame, really...
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Re: A358 Taunton to Southfields

Post by Berk » Wed Mar 29, 2017 23:05

Unfortunately, I think this is a different ball game to Chichester. Lack of support to the proposals won't stop any one of them being built??

Maybe the 'least worst' option, or the one with the 'most votes'. Can't see HE backtracking on this one.

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Re: A358 Taunton to Southfields

Post by jackal » Wed Mar 29, 2017 23:07

There's only one option in the consultation (the one in the OP), and it stinks. That's the problem.

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Re: A358 Taunton to Southfields

Post by M5Lenzar » Wed Mar 29, 2017 23:38

I can't see how a roundabout GSJ at the M5 is even being considered as a valid option. A main route like this is screaming out for freeflow - even if it's just a trumpet.

What was being smoked whilst they did a COBA?

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Re: A358 Taunton to Southfields

Post by jackal » Thu Mar 30, 2017 02:05

The economic appraisal clearly comes out against the consultation option (1.54 BCR) and in favour of the freeflow options (especially option 2A/2B, which has 2.08 BCR). But the last few pages of the Technical Appraisal Report starts waxing lyrical about how plugging housing developments into the new junction will magically make everyone rich no matter what the nasty economics says.

It seems the consultants may have been leaned on to ignore the objective facts and support a development corridor-type scheme no matter what.

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c2R
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Re: A358 Taunton to Southfields

Post by c2R » Thu Mar 30, 2017 07:53

In my opinion it's still the wrong route anyway - improvements to the A30 and A303 will continue (e.g. the current scheme for north of Honiton) and this if upgraded to full expressway standard in the long run will provide an eventual alternative route and resilience for the M5....
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Re: A358 Taunton to Southfields

Post by RichardA35 » Thu Mar 30, 2017 08:43

c2R wrote:In my opinion it's still the wrong route anyway - improvements to the A30 and A303 will continue (e.g. the current scheme for north of Honiton) and this if upgraded to full expressway standard in the long run will provide an eventual alternative route and resilience for the M5....
I imagine the benefits of upgrading the existing corridor in any form will be very slight once the appraisal removes most of the strategic traffic from the route and the scheme will quietly die a death, especially as there are few housing development opportunities to open up with the area being quite a way from anywhere.....

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Re: A358 Taunton to Southfields

Post by JonB2028 » Thu Mar 30, 2017 09:40

RichardA35 wrote:I imagine the benefits of upgrading the existing corridor in any form will be very slight once the appraisal removes most of the strategic traffic from the route and the scheme will quietly die a death, especially as there are few housing development opportunities to open up with the area being quite a way from anywhere.....
Agree, Richard - wishful thinking was my reaction on learning of the DCC scheme.

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Re: A358 Taunton to Southfields

Post by roadtester » Thu Mar 30, 2017 09:45

jackal wrote:The economic appraisal clearly comes out against the consultation option (1.54 BCR) and in favour of the freeflow options (especially option 2A/2B, which has 2.08 BCR). But the last few pages of the Technical Appraisal Report starts waxing lyrical about how plugging housing developments into the new junction will magically make everyone rich no matter what the nasty economics says.

It seems the consultants may have been leaned on to ignore the objective facts and support a development corridor-type scheme no matter what.
Be thankful for small mercies - at least there don't so far appear to be any plans to incorporate an MSA into the roundabout junction with the M5...

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Re: A358 Taunton to Southfields

Post by ChrisH » Thu Mar 30, 2017 12:01

jackal wrote:The economic appraisal clearly comes out against the consultation option (1.54 BCR) and in favour of the freeflow options (especially option 2A/2B, which has 2.08 BCR). But the last few pages of the Technical Appraisal Report starts waxing lyrical about how plugging housing developments into the new junction will magically make everyone rich no matter what the nasty economics says.

It seems the consultants may have been leaned on to ignore the objective facts and support a development corridor-type scheme no matter what.
I was in a meeting with HE only last week where they presented the findings of their Post Opening Project Evaluation (POPE). One of the clearest conclusions is that free-flowing links perform much better than signalised ones. So why are they now proposing signalised junctions as part of their newest schemes?

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Re: A358 Taunton to Southfields

Post by Sou'wester » Thu Mar 30, 2017 14:59

Whilst a freeflow would be ideal, as a local and regular user of this atrocious road, a dual carriageway is what is needed first and foremost.

J25 is currently over-loaded, so this option will reduce the pain currently happening there, whilst J26 is too far south for access to Taunton, really. I can see why a J25a is in the pipeline as there are extensive plans for a large expansion of Taunton in the Comeytrowe/Trull area, so this would probably mean a new southern bypass for Taunton is in the offing, which would be a positive outcome of this decision.

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Re: A358 Taunton to Southfields

Post by PeterA5145 » Thu Mar 30, 2017 15:05

ChrisH wrote:I was in a meeting with HE only last week where they presented the findings of their Post Opening Project Evaluation (POPE). One of the clearest conclusions is that free-flowing links perform much better than signalised ones.
It needs a study to tell them that? :roll:

An evaluation of the lavatorial habits of bears comes to mind...
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Re: A358 Taunton to Southfields

Post by ChrisH » Thu Mar 30, 2017 16:34

PeterA5145 wrote:
ChrisH wrote:I was in a meeting with HE only last week where they presented the findings of their Post Opening Project Evaluation (POPE). One of the clearest conclusions is that free-flowing links perform much better than signalised ones.
It needs a study to tell them that? :roll:

An evaluation of the lavatorial habits of bears comes to mind...
The religious affiliation of the POPE also comes to mind :)

To give them a bit of credit, I think the finding is that even on a BCR front, grade-separating a junction is worthwhile despite costing a lot more than at-grade options - and potentially increasing environmental impacts etc. Clearly the benefit to drivers is an aspect of that.

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Re: A358 Taunton to Southfields

Post by roadtester » Thu Mar 30, 2017 16:42

I must admit I thought it was silly when I first read it too, but presumably it's not just a question of deciding that a free-flow junction is better, but also trying to quantify how much better in order to make a better decision.

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Re: A358 Taunton to Southfields

Post by c2R » Thu Mar 30, 2017 19:39

It's a bit disappointing that on this one there are no questions about the usefulness of the consultation materials, as the summary document itself fails to be clear on the scheme objectives, and doe not go into detail about the junctions or the sort of road proposed, while clearly the technical document discusses this in greater detail, along with the rejected options. The reasons for rejection of 2A/2B aren't overly satisfactory. The questions about use of the stretch are a bit confusing as well - I have very little experience of using the route, but that is clearly because I either use the M4/M5 or A30/A303 - in the current nine miles extra to drive up to Taunton to join the M5 I would be almost third of the way in covering the 30 miles from Southfields to M5 - with the very empty Honiton to Exeter stretch in my sights, but the question doesn't ask how often I use the A303/A30. One of the responses also had "other (please specify)" but didn't leave anywhere to specify.
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