Chichester bypass upgrade

[wrinkly]

I don't think this falls within any existing thread (though there's one for a non-existent Chichester northern bypass).

Consultation and exhibitions coming up on upgrades to the A27 Chichester southern bypass.

Press release, with brief description of the optons

Scheme website

Latest newsletter

All three links have details of the exhibitions.

[jackal]

I don't think this falls within any existing thread (though there's one for a non-existent Chichester northern bypass).

Consultation and exhibitions coming up on upgrades to the A27 Chichester southern bypass.

Press release, with brief description of the optons

Scheme website

Latest newsletter

All three links have details of the exhibitions.

Thanks for this. No plans seem to be available online but the proposals are similar to the less ambitious of the earlier leaked plans. The higher capacity leaked options (4 and 5, which were for a northern bypass, and 6, which fully GSJed in the southern corridor) have been discarded. The options in the 'brief description' you mention seem to roughly correspond to the leaked options as follows:

new slip roads at two junctions (Fishbourne and Bognor) and restricted access at others [option 2 alternative link road]
new slip roads at two junctions (Fishbourne and Bognor), restricted access at Oving only - no works at Stockbridge or Whyke [option 1]
new slip roads at two junctions (Fishbourne and Bognor) and restricted access at others plus closures at Stockbridge and Whyke (north to south movements retained), a new Stockbridge link road from Fishbourne to B2145 [option 2]
junction improvements with traffic signals at majority of junctions (except Portfield) and some restricted access [option 3]
junction improvements with traffic signals to Fishbourne, Stockbridge and Whyke, new improved slip roads at Bognor Road - widening to three lanes between Fishbourne and Bognor Road - no works at Oving or Portfield [option 1 and 3 hybrid]

The best of the five remaining options are the two versions of option 2, then 1, then the hybrid, with 3 the worst.

[wrinkly]

No plans seem to be available online

Possibly will be from the date of the first exhibition. It often happens that way.

[Truvelo]

Why am I not surprised the best two options have been discarded

If every junction is GSJ'd bar one then the last remaining at-grade interference will be a bottleneck for years to come.

[jackal]

Why am I not surprised the best two options have been discarded

If every junction is GSJ'd bar one then the last remaining at-grade interference will be a bottleneck for years to come.

If they hear that they'll go for option 3 and we'll have no GSJs

[stempy81]

New consultation has started...

https://www.gov.uk/government/consultat ... ent-scheme

[Richardf]

Just had a look at the proposals. Cant see the point of a scheme where some junctions are gsj-ed and some are turned into signalised crossroads. If anything it would make things worse, speeding up some sections only to bring traffic to a grinding halt in others. Arguably the existing signalised junction causes enough hold up, and now they want to add more? in that case why not just signalise or 'hamburger' the whole lot and be done with it.

No, nothing less than full grade separation (at least) will fix the bypass problem.

[M19]

Full grade separation is needed, otherwise it's just designing in congestion that will cost the amount of the whole scheme to fix. When will they ever learn?

Even with the GSJs the designs are awful with roundabout geometries that promote severe entry path overlaps.

[Chris Bertram]

Just had a look at the proposals. Cant see the point of a scheme where some junctions are gsj-ed and some are turned into signalised crossroads. If anything it would make things worse, speeding up some sections only to bring traffic to a grinding halt in others.

Sounds like the A4174 Avon Ring Road, a mixture of flat roundabouts, signalised junctions and the odd GSJ. Flows freely ... at about midnight, all other times it's join the queue.

[jackal]

Option 2 is fine - it grade separates or LILOizes five consecutive junctions. Yes, I'd like to have seen the sixth and final junction GSJed as well, but how realistic is that when option 2 is already costing £280m compared to £47m for option 3? That final junction is also very expensive to GSJ due to the proximity of the water, requiring a long bypass or complex engineering, and would put the BCR in the toilet, probably meaning we get the no grade separation option 3 instead.

Be careful what you wish for.

[ThelwallViaduct]

Option 2 is fine - it grade separates or LILOizes five consecutive junctions. Yes, I'd like to have seen the sixth and final junction GSJed as well, but how realistic is that when option 2 is already costing £280m compared to £47m for option 3? That final junction is also very expensive to GSJ due to the proximity of the water, requiring a long bypass or complex engineering, and would put the BCR in the toilet, probably meaning we get the no grade separation option 3 instead.

Be careful what you wish for.

The huge difference in costs are due to the 20 buildings requiring demolition in Option 2 compared to a maximum of 5 elsewhere.

[jackal]

Option 2 is fine - it grade separates or LILOizes five consecutive junctions. Yes, I'd like to have seen the sixth and final junction GSJed as well, but how realistic is that when option 2 is already costing £280m compared to £47m for option 3? That final junction is also very expensive to GSJ due to the proximity of the water, requiring a long bypass or complex engineering, and would put the BCR in the toilet, probably meaning we get the no grade separation option 3 instead.

Be careful what you wish for.

The huge difference in costs are due to the 20 buildings requiring demolition in Option 2 compared to a maximum of 5 elsewhere.

That and the additional structural content (bridges).

[stempy81]

A few thoughts...

Nice to see the SDLs on the maps to illustrate just how much development there will be in Chichester over the next few years.

The budget is supposed to be up to £250 million though it seems Highways England are suggesting a figure of £100 million will be more likely:
http://www.bbc.co.uk/news/uk-england-sussex-36791497

Obviously option 2 is the least worst of those up for consultation in terms of capacity and peak journey time improvement but I doubt it will be popular with local residents due to the demolitions involved and construction of the link road across open countryside. Also, with an estimated construction cost of £280 million it appears a non-starter.

I think the Machiavelli in me would be tempted to go for option 3 (£47 million for a few traffic lights? I know there is more to it than that but still...). I doubt it will improve capacity and could even make the situation worse. Hopefully in time this would prompt a clamour from local people for a proper solution (northern bypass?). The current A27 alignment and future development rules out a GSJ at Shopwhyke anyway.

Hopefully one of options 1, 1A or 3A is the compromise solution that actually gets built.

[M19]

Maybe best to leave it then until things get bad enough ( or worse) to merit a proper scheme than something half arsed, as the options suggest.

[Lil]

I would rather they built the option which would solve much of the problems (the one with the Stockbridge / Hunston link in), than bothering about the other options. They may as well spend the money on something more deserving like the NHS than delivering little improvement.

The northern route will always be a non starter, there are too many vested interests with loud voices in the corridors of power, and also it encroaches even further into the national park, so if disturbing a tiny pocket of the Fishbourne AONB causes uproar.

[jcb336]

This is really depressing. If this is the best HE can come up with for such an important route then we're fast becoming a third world country. Replacing roundabouts with traffic lights is a complete waste of money on a trunk road of this importance. It really is the pinch point mentality. That's fine for sorting bottleneck problems, but the A27 needs to be an expressway. Putting forward inane proposals like this helps no-one. However if this is what we're stuck with then option 2 has to be the best since it provides through running for all but the most easterly roundabout.

[sotonsteve]

Option 2 is a decent scheme, and it is the only one that will actually improve things for both through traffic and local traffic. Option 2 is the best solution for the long term, and the best solution for facilitating population growth in the area. All the other ones trade off through traffic against local traffic and are severely compromised. Options 3 and 3a are a complete and utter joke and I think myself and most people other than NIMBYs and BANANAs would be angry at these options being selected.

Option 1 and 1a are semi-decent, as they grade separate two junctions on the route. The problem is, with option 1 turning movements are restricted at Stockbridge and with option 1a the current layout is retained. Stockbridge Roundabout is such a bottleneck at present because there is so much turning traffic. You can't simply ban people from turning right and think all will be OK. It's fine for through traffic, but it will punish the locals. Highways England may assume in their infinite foolishness that traffic will use the bypass and use the Fishbourne or Bognor Road junctions to U-turn, but we all know that won't be the case. Instead, traffic will rat run onto other routes to get around the banned turns, and roads such as Terminus Road and Vinnetrow Road will get significantly busier.

[Richardf]

Isn't it bad enough to warrant a full on scheme now? Just how bad does the Bypass have to be to justify full grade separation then?

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[SteveA30]

Have sent off a response but, will attend one of the exhibitions in Aug/Sept to present my master plan in the latest Pencil 2.0 software. Unless someone here can do a professional version off the computer.....

[Fluid Dynamics]

Having dropped the northern bypass Option 2 is the best option in my opinion and far better than the previously published scheme. Having just come back from the Netherlands and witnessed their engineering I am a little perplexed at why the Stockbridge and Whyke Junctions can't be dealt with by the A27 going over or under the local roads without the need for so much demolition, embankments and retaining walls to carry the local roads over. I know the water table is supposedly an issue, but never seems to be for the Dutch. I'll let someone better qualified than me in such matters to comment.

A pity about the Portsfield junction, but that's generally less a problem than Fishborne, Stockbridge or Bognor Road. One minor improvement would be to add a westbound filter lane for A27 traffic to bypass the roundabout, this could perhaps be combined with having the westbound carriageway D3 between Portsfield and Bognor Road.

For every other option I think the HA needs to be reminded of its supposed expressway policy.

If not I'd go for 1a, at least that restricts the pain to a couple of junctions and doesn't needlessly spend money on those other junctions that will need to be sorted in the long run.

But the question is why consult on the various options if there's only £100m available. If that's the real situation, at least go for 1a and admit it will all be grade separated but in a piecemeal fashion.