Have your say on proposals for a new Lower Thames Crossing

For over 50 years, the Dartford Crossing has provided the only road crossing of the Thames east of London. It is a critical part of the UK’s major road network and it is under considerable pressure – it is full, there’s no more capacity.

The location of the current Dartford Crossing east of London, ‘one of the worst performing parts of the UK’s strategic highway network’
The location of the current Dartford Crossing east of London, ‘one of the worst performing parts of the UK’s strategic highway network’
  • Updated: 21 March, 2016
  • Author: Martin Potts, Head of Consultation for the Lower Thames Crossing

The crossing is designed for 135,000 vehicle crossings a day, a figure that’s regularly exceeded.

Rather than one crossing, the Dartford Crossing is made up of three specific pieces of infrastructure. Two tunnels, one built in the 1960s and the other in the 1980s take the northbound traffic, with the QEII Bridge taking the southbound vehicles. It’s a complicated layout which can lead to confusion. Furthermore, although the road is classified as the A282 it is also a fundamental part of the M25 (see image above), carrying local, regional, national and international traffic from the channel ports to the manufacturers in the Midlands and the North.

The two tunnels are a particular problem. Built to older specifications neither can accommodate vehicles with hazardous loads. When these vehicles approach the tunnels they need to be taken out of the traffic flow and escorted which can cause congestion and delays on the approach roads and also on local roads. To further add to the unreliability of the crossing, the 1963 tunnel cannot accommodate over-height vehicles so if one approaches this tunnel, it too has to be taken out of the traffic flow and directed toward the newer tunnel, again causing delays.

Unfortunately this means that the Crossing is one of the worst performing parts of the UK’s strategic highway network. When the Crossing closes, which can happen over 300 times a year, traffic quickly backs up onto local roads and road users have no alternative but to:

  • Wait it out
  • Travel the 30-mile round-trip to use the Blackwall tunnel
  • Travel the other way around the M25 (as many haulage companies have said they prefer to do) – an extra 100 miles.

The Freight Transport Association has said that an HGV stuck in traffic costs £1 a minute and we know from bitter experience that it typically takes three to five hours for the roads to clear following a closure – it’s clear that these costs to users quickly add up to significant sums.

Following a series of studies and a public consultation in 2013, the Government commissioned Highways England (the operator of the country’s motorways and major roads) to consider options to alleviate the congestion at the crossing. Two different locations were identified, Location A would involve adding capacity to the existing Dartford Crossing and Location C would be a brand new road linking the M25 and the A2/M2 east of Gravesend. (Location B, a route across the Swanscombe Peninsula, was ruled out following the 2013 consultation.)

Assessing the options

Highways England developed and assessed a wide range of potential solutions and preliminary routes to identify options that were technically feasible. We tested these against the scheme objectives to reduce congestion on the existing Crossing and to improve its resilience (for a full list of the objectives please see our website). We took into account traffic flow forecasts, using computer models to calculate reductions in journey times and congestion. These options were evaluated against technical, economic, environmental and traffic criteria as well as cost and value for money.

The proposed scheme

As a result of this work, Highways England are consulting on three routes north of the river and two routes to the south (see graphic). For more information on the routes that we are consulting on, please download our comprehensive consultation booklet. Our proposed scheme, Route 3, would be a dual carriageway connecting junction 1 of the M2 to the M25 between junctions 29 and 30. This crosses under the River Thames just east of Gravesend and Tilbury. Of all the potential options, this route would provide a 70mph motorway-to-motorway connection with the greatest improvement in journey times and a modern, high quality road along its entire length.

Potential Thames Crossing routes
The three routes on which Highways England are consulting

The new crossing would be a bored tunnel, providing the required capacity with the least impact on local communities, protected habitats and species. It would have two lanes in each direction and could potentially be built with space for a future increase in capacity. The proposed tunnel is to be approximately two miles long.

We are at an early stage of the development process and we want everyone to have their say on the proposals, this is a once in a lifetime opportunity to sort out a major problem on the strategic road network and to boost local connectivity, potentially resulting in new jobs and homes. Please look at our website, review our documents and provide your feedback. The consultation closes on 24 March so you don’t have long to have your say.

Infographic stats for dartford crossing

About the author

Martin Potts CEng MICE is head of consultation for the Lower Thames Crossing at Highways England.