Previously the scheme was to feature two lanes in each direction, with passive provision for a third lane inside a 3.8km long tunnel beneath the river. But revised traffic forecasts have led Highways England to put forward a more extensive build, increasing the upper end of the project cost from £6.2Bn to £6.8Bn.

“Our traffic model shows there will be substantially more traffic than we first anticipated, so we have designed according to that model and that is why we will create additional capacity,” said Highways England project director Tim Jones.

Providing the extra lanes will, it is hoped, help to direct heavy goods vehicles in particular away from the existing Dartford Crossing. It is thought that the new tunnel and associated link roads will reduce traffic at Dartford by 22%, with 14% fewer vehicles using it every year.

Around 180,000 vehicles currently use the Dartford crossing every day. The Lower Thames Crossing aims to accommodate around 80,000 vehicles a day when it first opens in 2027.

Highways England says that the new road link will almost half the northbound journey times for motorists at Dartford. The new road tunnel will be the longest in the UK and the third largest bored tunnel in the world.

Other changes to the plan include an extension to the Lower Thames tunnel so that its entrance is 600m further south, a new design for a junction at Tilbury, removing a proposed link road in the area and an improved junction with the A2 in Kent. The road will be lowered by up to six metres in places to reduce its visual impact and be moved 80m east where it passes Chadwell St Mary to increase the distance to local houses.

The new link road will extend from the M2 near Rochester in Kent to the M25 in Essex between North and South Ockenden.

Variable road charges are proposed at the new crossing to allow Highways England to have more control over the volume of traffic using each crossing, with a possibility of variable charges at Dartford in future years.

A 10 week consultation on the latest designs for the Lower Thames Crossing begins today, with 25 public information events taking place and 30 visits to local communities. Two years ago 47,000 people responded to an earlier consultation on the proposal, said to be a record for a UK road scheme.

“We think this will be the most extensive consultation any road project has conducted,” added Tim Jones. “This scheme is unprecedented in terms of the amount of information that is being released; it gets a much better conversation going so that people can start forming judgements.”

Photo Credit: Highways England