Anne Robinson 21st August 2024: The biggest new road scheme by far to be reassessed by the review of the DfT transport infrastructure portfolio commissioned by the Chancellor and Transport Secretary on 28th July is the proposed Lower Thames Crossing. But to understand the merits/demerits of this project it’s necessary to first describe the situation facing road traffic seeking to get from one side of the river to the other. At the moment the only road crossing of the Thames east of London, the Dartford Crossing, is one of the UKs most strategically important roads. It carries over 50 million vehicles a year – nearly 40% of these are goods vehicles travelling through the Port of Tilbury and Dover, London Gateway and Medway, and on to the Midlands and the North.
Starting as a 2-lane tunnel in 1963, another 2-lane tunnel was added in 1981 and the 4-laned QEII bridge was opened in 1991 – offering 4 lanes in each direction. The Dartford Crossing is now operating over its design capacity of 135,000 vehicles a day, with between 150,000 and 180,000 a day. Abnormal and dangerous loads require an escort with tunnel closures every 15 minutes during peak times. This congestion (video here) leads to delays, long queues and rat running on local roads with associated air and noise pollution, and a large number of incidents.
The proposed solution – not just the Lower Thames Crossing but a new A122 road as well – would be 23km long, 4.25km of which would be in tunnel, with the portals near the village of Calk (south of the Thames) and to the west of East Tilbury (north of the Thames). It would connect the M25 in Essex with the A2 and M2 in Kent, with 3-lanes in each direction but as an A road would have no hard shoulder. If the project is approved and then mobilised, construction itself is anticipated to take 6 years and be complete by 2032.
So far National Highways (NH) is saying that it would cost £9billion and would have a Benefit Cost Ratio (BCR) of 1.22. It claims the new route would remove 13million vehicles a year from the Dartford Crossing, create 400,000 jobs, improve journey times and allow traffic to become free flowing. By 2050 it would, NH says, help the Thames estuary add £190bn to the UK’s GDP. A new crossing was first proposed in 1989, and underwent a multimodal study in 2002 and a study of potential solutions in 2009. Despite inadequate assessment of alternatives, the preferred road route was announced in 2017 but it took a further 6 years for the planning application to be submitted. The Examination opened in July 2023 and closed in December 2023. A decision due on 20 June 2024 on the scheme was postponed by the Transport Secretary until 4 October.
There has been much lobbying of both Houses of Parliament for this project to progress. So much for the Pros but what about the Cons, because it’s always important to consider the other side of the story. Its stated cost of £9bn dates from in 2021, which will since have risen with inflation. It’s that huge number that will be scrutinised by the Chancellor’s infrastructure review which is primarily driven by value for money and public expenditure concerns. As she said: ‘If we cannot afford it, we cannot do it’.
The Benefit Cost Ratio of 1.22 puts the Lower Thames Crossing in DfT’s low value for money category – for every £1 spent only 22p is returned to the economy. Claims of it promoting economic growth through agglomeration in the Thames estuary have not been substantiated. There is no compelling evidence that new road capacity supports economic growth as shown by DfT, Imperial College London, and the Welsh Assembly Government. Most convincing is National Highways own evaluation reports for 80 of its strategic road schemes, of which 25 had been justified, prior to construction, on the basis of their expected economic benefits. On completion however the majority had either no, weak, or only anecdotal evidence of economic impact.
In terms of the scheme’s carbon impacts, these have to be understood within the context now analysed by the report Will Labour fail its ‘transport decarbonisation test’?, which describes how DfT policy over the last 2 decades has failed to achieve any transport decarbonisation in the first half of the 60 year period to Net Zero in 2050, so that now 70% of the UK carbon reduction ‘policy gap’ is attributable to transport. What the Lower Thames Crossing scheme does is add 6.6MtCO2e over its 60 year life by a combination of construction emissions and the additional road traffic that will be induced by it. Seeing that the UK Carbon Budget Delivery Plan has already twice been found to be unlawful because it did not sufficiently demonstrate how it could achieve the emissions reductions required, pursuing schemes such as the Lower Thames Crossing is likely to throw the CBDP off course and into another legal challenge.
This is the broader argument against schemes like the LTC. Instead of spending around £10bn on a ‘solution’ that will not be available until the early 2030s and then will increase carbon emissions, what the new Labour government needs to do is switch its roads policy now decisively towards decarbonisation through a combination of reduction in road traffic of around 20% by 2030, in parallel with a strong EV transition. What is needed is creative thinking about making more efficient use of existing road infrastructure through demand management rather than constructing ever more physical infrastructure. Even if the Chancellor is able to construct a funding approach by which the LTC could proceed via private financing, as is being talked about, that just perpetuates the road carbon policy gap. If such a deal proves too risky then the £9+bn public expenditure needed for this single road scheme is likely to jeopardise priority rail improvements in the North, promised by the Transport Secretary, and estimated to cost £30bn.
Other negative impacts abound. Relief on the Dartford Crossing would be short lived. Within 8 years unconstrained traffic would accumulate to recreate current congestion. There would be more accidents (including 26 fatalities), more noise pollution, an increase in air pollution, large adverse impacts on the historic environment and very large adverse impacts on habitats and wildlife. The harm to the Kent Downs AONB would be immense with an enormous interchange in its setting, widening of the road through it and loss of many trees including ancient woodland. The lack of a hard shoulder on a 6-lane road creates a Smart Motorway by stealth, despite the government having ruled out any more on safety grounds.
Cancelling the Lower Thames Crossing would be a powerful indicator of the new government’s commitment to UK decarbonisation, sensible constraint of travel demand and its public transport goals.
You can read more about the case against the LTC scheme on the website of the Lower Thames Crossing action group.