Greenwich Society response to TfL

The Greenwich Society has responded formally to the recent TfL consultation on their plans for a new road tunnel between the peninsula and Silvertown.

Silvertown Tunnel Consultation 2015 – Greenwich Society comments

The Greenwich Society has about 1,000 members and represents their interests in the area of the Royal Borough west of the A102. We welcome the opportunity to comment in response to the current TfL consultation on the Silvertown Tunnel scheme.

In response to earlier consultations we have asked for detailed traffic forecasts to assess the likely impact of the new tunnel on congestion and air pollution in this area. We therefore welcome the forecast material now provided. We accept that, based on available current information and methods, the main case for the tunnel is well founded – that although there may be small increases in traffic on some local roads these are likely to be outweighed by the decreased delays to traffic through the Blackwall Tunnel. (We note, however, that the current effect of congestion on air pollution appears not to be demonstrated by quantified evidence; this would require a comparison of pollution levels when east London river crossings are at their most congested, with those when they are free flowing).

Our main concern reflects the fact that the forecasts necessarily rest on assumptions about future behaviour, and hence are bound to remain to some extent uncertain until the tunnel opens. Two aspects of this uncertainty are particularly important from our point of view:

  • Given that the new tunnel would add to traffic on the main roads, would there be delays at other pinch-points on the A102 junctions to the south offsetting reduced congestion/pollution on the tunnel approaches? – Figure 7.1 in the Preliminary Transport Assessment (PTA) suggests an increase as high as 30% in PM peak traffic, though this seems not to be reflected in figures elsewhere.
  • PTA Figures 7.18-20 show worse congestion at junctions on some local roads, which is already bad at peak times through Greenwich Town Centre and along the A2, and is bound to be aggravated in any case by the huge new developments on the Peninsula, generating more construction, delivery and other traffic. It is inevitably hard to estimate the extra impact of the new tunnel, both on additional feeder traffic to and from the tunnel, and on net diversion through Greenwich to the Rotherhithe Tunnel and further west to avoid tolls.

The Greenwich Society has long taken the view that traffic congestion, with the resulting air pollution, is one of the most serious problems affecting our area. With increasing development this will get worse, and we accept that there are no strong grounds for challenging the TfL case that a new Silvertown Tunnel would be better than doing nothing, from this point of view, as well as delivering other benefits. But given the uncertainties, we welcome the undertaking to “monitor traffic levels before and after the opening of the new tunnel”, and to “take appropriate measures to manage and mitigate any negative effects”. There is an acknowledgement that “a need for junction mitigations could emerge”, though the expectation that these will not require “work outside the existing highway boundary” seems to us questionable at this stage. It will be important to state this in the application for development consent as a firm commitment

  • - to monitor systematically the effect on the whole area, including all the river crossings, before and after the tunnel opens;
  • - to carry out a detailed review, in consultation with local authorities and communities. In the light of the first year’s monitoring results, to examine and reach decisions on possible mitigations such as junction improvements, toll changes and information systems (the proposed 5-year ‘monitoring and mitigation strategy’ time-table is too relaxed; as the document says, “changes to traffic patterns might be expected to reach a relatively stable position [after] 3-6 months”).

We welcome the improved cross-river bus service, and the proposed Community Fund, and would expect to see these also set out as detailed commitments in the application.

We recognise the need to impose toll charges on the Blackwall Tunnel as part of the package. However, local residents are being asked to accept worse congestion and pollution at some junctions, for the sake of greater benefits for traffic through the tunnels. They are also being asked to accept the principle of paying tolls to cross the river while other road crossings in inner London continue to go free. There is a strong case for a residents discount of say £1 for account-holders living in the area (so that on the proposed ‘indicative’ rates lighter vehicles could continue to go free off-peak). Residency qualification could easily be checked when account applications were registered, and then applied automatically. This has been rejected so far on the grounds that a discount for “large numbers of people….could increase the demand to use the tunnels, potentially to a level beyond the capacity of the local road network”; but tolls would still be a disincentive to travel at peak times and for heavier vehicles, as against the existing entitlement to toll-free crossing.  

Alan Bailey
Chair, Greenwich Society Planning Committee