Frequently Asked Questions

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Stop the Silvertown Tunnel Coalition. June 2022

The Silvertown Tunnel project. Frequently asked questions

1. Work has already begun, so isn’t it too late to cancel the tunnel?

The work done so far is preparatory work. The tunnel boring machine has not started work. This is the main piece of equipment for the tunnel, and is not single-use (see here), i.e. it could be sold on the market for use elsewhere. If a project is based on flawed premises, it is better to cancel it, even at a late stage, than to continue.

2. Wouldn’t cancellation leave Transport for London with a huge bill to pay?

The short answer is that going ahead with the tunnel project will cost TfL £1.7 billion, or more, in excess of the cost of cancellation. Budget proposals presented to the London Assembly on 24 February (see here), but not supported by a majority vote, included the cost of cancelling the scheme. Although the Mayor has refused, despite repeated requests, to reveal the cost of the major item, i.e. the terms of the contract with Riverlinx, City Hall staff have confirmed that £500 million is a reasonable estimate (see page 6 of the proposals).

Those budget proposals allowed for that sum to be borrowed against future income, including smart road charging, to cover the cost of cancellation. It should be borne in mind that the Mayor has himself expressed the intention of introducing road charging by 2030. Estimates of the total cost of the tunnel, should the Mayor proceed with it, are between £2.2 billion and £2.5 billion (see, e.g., here).

3. The Mayor’s office has said that the tunnel project will not increase the volume of traffic, so what is the problem?

There is no basis for the claim that the tunnel project will not increase the volume of traffic. The fact that more roads produce more traffic is a fundamental principle, established by decades of transport research, and set out in reports to the government in 1994, 1998 and 2018 (See the Stop Digging report, page 10).

TfL itself admits that the tunnel is likely to produce more traffic. Flyers distributed to local residents by TfL say that, without a user charge, the tunnel would result in a 15-30% increase in traffic on the A2/A102 route approaching the tunnel. Modelling conducted by TfL, prior to applying for the DCO, indicated that the scheme would increase traffic and associated carbon emissions, and that by 2036 this would result in 23,000 tonnes of CO2 per year in additional emissions, compared to a scenario in which the tunnel is not built. (See the Energy and Carbon Statement, and this news story.)

4. But isn’t there is a user charge built into the scheme, which will keep traffic levels down?

The Development Consent Order (DCO) for the tunnel project provides for a user charge on both the Silvertown tunnel, if built, and the Blackwall tunnel – but (i) the charge can be reduced or cancelled by a future Mayor, and (ii) even if it is imposed, there is no guarantee that it can be used to set levels of traffic in the way that TfL office claims.

(i). The Stop the Silvertown Tunnel Coalition, and the Royal Borough of Greenwich, have both separately received legal advice confirming that the imposition of the user charge is a political decision for all Mayors serving during the lifetime of the project. There are previous examples of such charges being adjusted or abolished due to local political pressure, and this could clearly happen in this case too. As Sadiq Khan himself pointed out in 2016 (see here), a charge for using the Blackwall and Silvertown tunnels would be seen as “a tax on east and south-east Londoners”, and this would be grounds for people to object to it.

(ii). There is no research-based evidence that the user charge will reduce traffic levels in the way that TfL claims. On the contrary, the experience of e.g. the Dartford crossing and the M6 Toll Road near Birmingham shows that, where there is a trend for traffic volumes to increase, the imposition of a user charge does not reverse it. At the Royal Borough of Greenwich transport, culture and regeneration scrutiny panel meeting in December 2021, the only occasion on which TfL representatives have appeared jointly with representatives of our coalition to discuss these issues, councillor Aidan Smith asked TfL if it could point to any project, anywhere in the world, where tolls have successfully been used to manage traffic levels, in the manner proposed. TfL representatives said they could not.

5. The Mayor’s Transport Strategy provides for a reduction in traffic volumes. Surely this takes account of the tunnel project, doesn’t it?

The Mayor’s transport strategy, published in 2018, envisaged not only construction of the Silvertown tunnel, but also public transport projects such as north-to-south Crossrail, and extension of the DLR to Thamesmead, that have moved no further forward. Meanwhile, as we emerged from the pandemic, the congestion charge was suspended in the evenings, public transport fares were increased. Now bus routes are being cut. The net result is that proposals tending to increase the volume of traffic have been implemented, while many of those tending to reduce it, and support public transport, have not.

Obviously this is not all the Mayor’s fault. The government also has a say in TfL financing; external factors such as the pandemic have played a role. But none of these are arguments for pressing ahead with a project that commits still more resources to expanding the road network, while public transport and alternative modes continue to suffer from shortage of funds.

6. Isn’t the main point of the tunnel to provide for more buses?

The DCO includes a commitment that TfL runs twenty buses per hour through the tunnel for the first three years of its operation (see here). But there is no commitment to bus transport subsequently. TfL and the Mayor’s office often refer to “dedicated bus lanes” in the tunnel, but there are no plans for such lanes. The DCO provides for the bus lanes also to be used by an unlimited number of Heavy Goods Vehicles. Certainly the haulage industry sees the tunnel project as an opportunity to reroute heavy traffic that currently uses the Dartford crossing. For this reason there are projects in progress to build new lorry parks on both sides of the river.

7. Could the tunnel be repurposed for “green” transport?

If construction proceeds – despite the wishes of most people in Greenwich and Newham, the opinion of local councils, and the advice of a wide range of researchers – it would of course

be better for the tunnel to be used for non-car modes of transport, e.g. bicycles, electric scooters, walking, etc, and/or for public transport, than to be used for cars.

8. Surely something has to be done about congestion at the Blackwall tunnel, doesn’t it?

Of course, something must be done. One cause of congestion is the excessive number of short closures, many of which are caused by overheight vehicles. This could be stopped with basic monitoring and policing methods, rather than building a new £2.2-£2.5 billion tunnel. A second cause of congestion is the excessive volume of traffic. Traffic managers have many options for dealing with this, and our campaign does not itself have any particular expertise – but park and ride schemes, better connections with public transport including the Elizabeth line, commuter buses, car-sharing and other measures, coordinated with local authorities in Kent, would obviously help.

The Mayor has set very welcome targets to reduce the volume of traffic by 2030 in line with climate targets. His announcement in January referred to a 27% cut in traffic volumes, although the more ambitious scenario in the report he commissioned recommended 40%. In any case, if London is going to contribute to averting climate disaster, these targets will have to be met. If we succeed collectively in coming anywhere close to them, there will be a reduction in traffic volumes crossing the Thames as well as throughout the whole road network. This, together with the measures mentioned above, would be more than sufficient to address the problem of congestion at the Blackwall tunnel.

9. Won’t the project help to tackle social inequality, by addressing the imbalance in river crossings between west London and east London?

Tackling social inequality should be at the centre of transport policy. To do this, public transport provision must be prioritised, which will help to improve transport options for those who do not have a car. The focus needs to be on active travel and public transport, with more climate safe streets and low traffic neighbourhoods, improving the situation for those without cars.

It is clearly established by researchers that the proportion of households who do not have a car is higher, the lower their income level. (See the Stop Digging report, pages 25-27.) Roughly half of residents in the boroughs affected by the tunnel do not have a car: car ownership in Greenwich is only 60%, and in Newham only 42% (see here).

The tunnel project does the opposite of what is needed. It does not address these inequalities in transport policy, but does exacerbate the problem of air pollution, which in turn exacerbates other social inequalities. Air pollution worsens the living standards of low-income families and Black, Asian and minority ethnic communities, more than others.

10. Opponents of the tunnel say it will make air pollution worse. But hasn’t the Mayor’s office taken account of this problem?

No, it has not. Firstly, the case for the scheme put together prior to the DCO being granted did not sufficiently cover air pollution problems. The smallest particulate matter, PM 2.5, which is now understood by researchers to play a role in the most serious health problems caused by air pollution, was not as well understood by international and national agencies then as it is now. This, together with amendments to the World Health Organisation’s standards in 2021, means that the studies conducted prior to the DCO are completely out of date. (See correspondence on the air quality assessment, here.)

Secondly, those studies were inadequate even at the time. As research by Friends of the Earth has shown, there were 14 sites studied prior to the DCO being issued at which air quality was expected by TfL to deteriorate. (See here.)

The London Assembly has in June 2022 asked the Mayor to instruct TfL to undertake new modelling of the project’s health, climate and congestion consequences, including a scenario in which no toll is charged (see here).

11. Doesn’t the standing traffic exacerbate the air pollution problem?

Transport and pollution researchers have compared standing traffic and moving traffic and there is no clear research-based answer to the question, about which is worse from an air quality point of view. (See the Stop Digging report, pages 7-8.) Some researchers who have addressed our coalition’s events have indicated that, if anything, moving traffic is worse, for example due to the effect of additional tyre wear. But there is no unambiguous answer to this question. So the idea that avoiding standing traffic is sufficient motivation for the tunnel project, with all its other negative consequences, is absurd.

12. Isn’t air quality being monitored, though, to ensure residents are protected?

Some monitoring of some pollutants is being conducted by TfL for three years before the tunnel opens and for three years after (see here). This does not cover PM2.5 particles, as mentioned above (question 10), although Tfl has, under pressure from Newham council, agreed to only a very limited amount of PM2.5 monitoring.

However, as far as we are aware, there are no contingency plans to deal with a situation in which the tunnel project worsens air quality, as air quality researchers expect that it will. The critical issue, in any case, is to improve air quality which, even without an additional tunnel, is very poor, with pollution exceeding levels defined as safe by the World Health Organisation.

A further issue is that TfL has now made clear that there will be no air vents from the Silvertown tunnel as designed. This will inevitably lead to a concentration of pollutants at the north and south entrances of the tunnel. (See here.)

13. Opponents of the tunnel say it will add to greenhouse gas emissions. Surely it’s a drop in the ocean of that global problem, isn’t it?

The impact of road projects on total greenhouse gas emissions is cumulative. The Mayor’s office has tried to trivialise the problem by citing estimates of emissions from construction as a proportion of total UK emissions. This is a dangerous fallacy. The Silvertown tunnel project must be taken in the context of the government’s strategic road-building programme, which will see an expansion of the motorway system and a further, emission-intensive river crossing – the Lower Thames Crossing at Dartford – that would follow the Silvertown tunnel. Climate scientists, and even the government’s own Climate Change Committee, have warned (i) that the transport sector is the one in which emissions reduction have made the least progress in

recent years and (ii) that a “business as usual” approach will result in it missing the government’s own targets – let alone those set by climate scientists – by a substantial margin.

Several teams of climate scientists have produced research that shows that, in order for international climate targets to be met, NO new projects to build fossil-fuel-intensive infrastructure – including roads and tunnels – should go ahead. (See our Briefing, October 2021, pages 13-14).

14. But government and the Mayor are both planning big emissions reductions: surely these will more than compensate, will they not?

The government issued a Transport Decarbonisation Plan in 2021. Climate scientists and transport researchers warned that it contained too many general statements, and no firm proposals for decarbonising the transport sector, and that this would likely lead to the government missing its own targets by a long way (see our Briefing, October 2021, pages 12-13). The Mayor’s targets, mentioned above, are very welcome, but can clearly only be achieved by policies that focus on reducing car traffic and improving other forms of transport. The resources put into the Silvertown tunnel project push in the opposite direction to what is needed.

Simon Pirani and Victoria Rance, 28.6.2022

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