Transport for London (TfL) is once again consulting on proposals for a new tunnel under the Thames that would link Greenwich Peninsula and Silvertown. Having been designated a Nationally Significant Infrastructure Project (NSIP) by the Government, the Mayor of London’s scheme is in the process of being “fast-tracked” through the planning system with this latest non-statutory exercise a precursor to a statutory consultation expected in the middle of next year prior to formal submission of an application for a Development Consent Order (DCO).
Opinion is sharply divided about the Mayor’s scheme. Its proponents argue that a new Tunnel will relieve congestion, reduce journey times, release constrained economic growth, bolster regeneration and provide a much-needed safety valve to a notoriously unreliable Blackwall Tunnel (improved “resilience” in the jargon). Its opponents, notably the local No to Silvertown campaign, contest each of these claims, arguing that the construction of a new fixed road crossing will simply induce more traffic into a saturated road network, increase already endemic levels of congestion and exacerbate existing problems of poor air quality in the vicinity of the A102.
Both sides agree that the status quo is untenable. As anyone that lives locally knows, congestion at the Blackwall Tunnel and on the surrounding road network causes misery for residents on an almost daily basis and is a potent source – particularly around the Woolwich Road flyover – of the noxious air pollution that is the cause of over 4,000 premature deaths in London every year. The debate is over how these problems are best addressed.
It is clear that simply building more roads is not a panacea for congestion or poor air quality and the argument that London requires additional road capacity simply to meet the demands of an expanding population is contested (car travel has actually fallen by around 15 per cent from its 1999 peak despite population and economic growth over that period). It is also obvious that continued investment in public transport – whether it’s new dedicated cycle crossings of the Thames, additional cross-river bus services, bringing the DLR to North Greenwich and Eltham or extending the London Overground from Barking Riverside to Thamesmead and Abbey Wood – will be essential if we are to sustain the long-term modal shift in journeys from private cars onto public transport and address the deficit of connectivity across the river that still hampers south east London.
Yet there is reason to doubt that public transport alone can provide a comprehensive solution to the particular problems associated with the Blackwall Tunnel. In particular, additional cross-river public transport on the Greenwich Peninsula will not address the reliability problems that plague that Tunnel, the majority of which are caused by overheight vehicles attempting to access the Victorian-era northbound bore. It is the Blackwall Tunnel's constraints, and the congestion they so frequently contribute to, which make life so difficult for local businesses that depend on a reliable road network and that act as a barrier to the better cross-river bus services we so desperately need (there are 47 bus routes which cross the river west of Vauxhall Bridge and only one, the number 108, that crosses it east of Tower Bridge). As a result, the rationale for the Silvertown Tunnel, particularly one that provides opportunities for significant public transport improvements such as new cross-river double-decker bus routes, cannot simply be dismissed out of hand as the latest craving of an insatiable pro-car lobby.
However, given the appalling congestion and dire air quality we already suffer from locally and the corresponding risk of making an already bad situation worse, the onus is on the Mayor and TfL as the scheme’s proposers to establish beyond reasonable doubt that the assumptions and analysis upon which the scheme’s purported benefits rest are sufficiently robust.
Unfortunately, the evidence and analysis that TfL has released to date has, in my view, failed to adequately meet that test. I’ve spent a considerable number of hours over the past few weeks trawling through the scores of technical reports released as part of the current consultation only to discover that, beyond high-level strategic modelling, important questions remain largely unaddressed and analysis that might have provided reassurance on crucial assumptions underpinning the scheme is still lacking.
Most critically, the latest consultation provides insufficient evidence to support claims that charging will provide a robust mechanism for keeping the additional traffic that a Silvertown Tunnel will induce onto the A102 and the surrounding road network within acceptable limits. The expectation that it can do so is entirely plausible as an assumption, yet given how heavily TfL’s case for an environmentally beneficial (or at worst neutral) tunnel rests on it, it is disconcerting that we have been provided with little beyond preliminary modeling. Neither do we yet have a firm idea of how the proposed user charging regime could adjust if demand was less price sensitive than assumed and additional traffic could not be managed effectively (a higher peak period rate is mentioned but is still being assessed and options tested). Nor are we given any assurance as to how the charging regime would be insulated from any future political pressure to amend or scrap it. Perhaps most worryingly, TfL has no plans at present to introduce charges for the Rotherhithe Tunnel. This would leave that Tunnel as the only remaining fixed road river crossing lying outside the congestion zone and not subject to charges, thus providing a clear incentive for drivers wishing to cross the river without charge to detour through Greenwich Town Centre and the World Heritage Site.
A host of other pressing questions also remain unanswered:
- Having not ruled it out in the consultation, what alterations to junction capacities and the southern approach roads that feed the A102 might be required if a new Tunnel was constructed?
- Will the scheme actually aid local economic regeneration, particularly in the immediate vicinity of the crossing point, given an absence of convincing analysis to attest to such effects and the fact that evidence of past crossing projects (Runcorn, Severn, Humber, and the Blackwall upgrade in the 1960s) points the opposite way?
- What evidence has been used to support the assertion that Blackwall will remain the principal strategic link on the Peninsula and that vehicles making non-local journeys will not simply opt to use the more reliable Silvertown link to join the A12 via the Lower Lea Crossing?
- Which local roads might be at risk of increases in emissions and what assurances are there that we will not see increases in NO2 and PM10s?
- Can we be certain that TfL’s modeling (in the absence of other data sources currently the only basis for traffic forecasting available) is sufficiently robust?
That no satisfactory answers have yet been provided to these critical questions is a source of concern. It is of course partly a result of the DCO process itself which, in focusing on frontloading consultation during the pre-application stage in order to reduce the determination period, involves successive rounds of consultation in which in principle public consent is sought for a scheme in the absence of the detailed analysis and evidence necessary to arrive at a reasoned judgment while technical preparations for its construction continue unabated. Whatever the ultimate cause, the result is that the current round of consultation does little to remove the skepticism that many of us feel towards the scheme.
Our guiding objective in coming to a final judgement on any proposed river crossings – and indeed any new transport infrastructure affecting the constituency – must be whether the proposals contribute to a sustainable local transport system that demonstrably brings benefits, in improved air quality, inward investment and expanded opportunities, to local residents. Despite some believing that Silvertown is “in essence a done deal” because the case has been made I still remain to be convinced.