Talk:Thames Gateway Bridge

Neutrality

This article reads like it was written by TfL themselves! Needs far more neutral description of the project, including the latest update that the Government decided TfL's projections were flawed and ordered a new inquiry, and that the Inspectors recommended refusdal for the project. That doesn't sound like the actions of a few whinging residents to me. Grunners 10:32, 7 August 2007 (UTC)

I think the neutrality issue has now been addressed but is the article now however too skewed to the inquiry and the outcome? Would it be appropriate to add more information in relation to the design of the bridge and the perceived benefits? Who designed it? when? What alternatives were considered? what about Boris's cable car idea? PeterIto (talk) 09:01, 10 November 2008 (UTC)

Traffic modeling

At the centre of this planning inquiry and at the Longdendale Bypass (also known as the A57/A628 Mottram-in-Longdendale, Hollingworth & Tintwistle Bypass)inquiry is traffic modeling. Both seemed to have had inadequate modeling. Is this worth developing this more?PeterIto (talk) 09:01, 10 November 2008 (UTC)

• Transport models are often innacurate (see Transportation forecasting#Inaccuracy.) However my POV is I would be surprised if modelling "error" was the major material factor in the enquiry's decision. You would need to have some concrete evidence to present this as a verifiable fact. I can't speak about the latest public enquiry but, for my sins, I worked on part of the traffic models for ELRC in the 1980s. The data sets were very comprehensive, being about as detailed as it was possible to calibrate against, and the resources I had access to were phenomenal for the time - some of the fastest CDC Cyber supercomputers around (albeit probably little more than a high-end PC today!). However, IIRC, there were some fundamental issues that made or broke the case back in the 1980s, revolving around local disbenefits versus regional regeneration benefits. Tangibly this went into an economic cost-benefit model, which was entirely underpinned by the perceived value of time of vehicle occupants (which values changed significantly during the study), and was then shifted again with changes to land use when the London City Airport was proposed (also resulting in a bridge redesign with much lower piers!). But the model's impact would also manifest itself in non-numeric ways, such as local access, community fragmentation and environmental pollution, as the access roads carve through local areas, versus new opportunities for regeneration, etc. It is inconceivable to me that all the learnings from the past models were ignored in the latest study. I imagine that the latest model faced equivalent challenges, and the Inspector weighed them accordingly. Ephebi (talk) 15:23, 10 November 2008 (UTC)

• I think the dilemma for road schemes these days is that generated traffic is seen as a bad thing, in the past it was probably seen as a sign of health economic activity. In the Mottram-Tintwistle case they have even include 'route restraint measures' in the scheme to artificially make the road less attractive to through traffic to try to avoid traffic diverting from other routes and making more journeys. Google route restrain measure and six of the first seven results are to do with that scheme; it is however possible that it is more relevant to that scheme than this one. Phil Goodwin's evidence to the bridge inquiry does however make interesting reading. PeterIto (talk) 19:29, 10 November 2008 (UTC)

• Ah, technically I think you were referring to the objectors mainly questioning the parameters used for the forecast, rather than the model itself. To test these parameters there should have been some sensitivity analysis done as well, though its not clear whether this was presented as evidence. Nonetheless, there is always scope to challenge those parameters. However its hard having read the cited summary document its hard to work out just what the problem in that area is. Nonetheless, its apparent that the same argument of wealthy commuters gaining at the expense of suffering local folk was still being used. However that argument is not a simple one - the claims that the road scheme would provide most benefit to people from out of town, should also be tempered by any economic benefits given to the local areas made more accessible for new business, and the ability to make social visits etc; this quality is very dependant on the detailing of local access versus priority to through traffic. And were the boroughs on either side of the Thames to use this as a catalyst to launch a mutual regeneration scheme equivalent to the Cross Rail Partnership then you might expect a broader set of local benefits - not that such speculative items could easily be incorporated in a Public Enquiry either.

A quick web search shows that that TfL did consider Prof. Phil Goodwin's evidence and responded with a 78 page rebuttal that investigated his argument in some detail and presented models using different parameters, without materially affecting their findings (albeit they were constrained to use certain government-mandated parameters which the enquiry was not empowered to challenge). Goodwin then responded to some of these rebutalls. If you were to amend the article here to present a blow-by-blow account his objections then in the interest of balance you would also have to set out the rebuttals (search for "TFL/REB/4985/1") - I suggest it would be challenging to do this in an encyclopaedic way without engaging in OR. Ephebi (talk) 22:33, 10 November 2008 (UTC)

• Ok, and I do agree with your arguments re 'OR' and I certainly don't think it would be appropriate to go down that route. Can I suggest, however, that it may be useful to provide links to the traffic modeling evidence, I certainly found your reference useful, however the approach should be a factual one, ie the opponents presented this document, and TfL responded with that documents, the inspector said 'xxx' with some links to some related traffic modelling articles built into the text. I may give that a go or may leave it to someone else :). Thanks PeterIto (talk) 05:05, 11 November 2008 (UTC)

• I think it would be hard to do an abstract fairly - although much was made of the prof's evidence, the summary evidence document is, IMHO, a bit unclear on its own. The consultant's lengthy response also makes reference to other documents and events that are not present. Links are about the best we could do without a lot, lot more effort. Your summing up of the Inspector's conclusion seems to read pretty well. 23:35, 11 November 2008 (UTC)