Highways England has unveiled revised plans to construct a road tunnel connecting Kent and Essex and almost double road capacity across the river Thames.
The revised plans includes measures such as extending the tunnel so the entrance in Kent is 600m further south.
Parts of the new road will also be lowered by five to six metres in an attempt to reduce its visual impact.
The multi-billion-pound Lower Thames Crossing project will create a new, three-lane dual carriageway connecting the M2 near Rochester in Kent with the M25 in Essex between North and South Ockenden.
The extra capacity will mean that northbound journey times at the Dartford Crossing would almost halve after the new road opens, the roads body claims.
Highways England has also said the 23km route connecting Gravesham in Kent and Thurrock in Essex will cut traffic using the Dartford crossings by 22% with 14M vehicles using it every year.
The project will include a 3.8km long tunnel under the Thames between Gravesend and Tilbury – the longest road tunnel in the UK – and, at over 15m wide, the third largest bored tunnel in the world.
Transport secretary Chris Grayling said: “We are making the biggest investment in improving our roads since the 1970s, ensuring journeys are quicker and safer.
“The Lower Thames Crossing will help transform journeys, create new business opportunities in Kent and Essex and unlock productivity across the UK.
“It will also cut congestion at the Dartford Crossing and improve connectivity from our industrial heartland to our ports in the South East.”
Lower Thames Crossing project director Tim Jones said: “The Lower Thames Crossing is the most ambitious project of its kind ever in the UK and the biggest single road upgrade since the M25 was completed more than 30 years ago.”
He added: “We have not done this in isolation over the last 18 months. We have worked very closely with interest groups, resident groups, action groups, stakeholders, local authorities and all the big statutory environmental bodies.”
Jones also stressed that Highways England had worked hard with businesses to ensure they understood the plans.
In a previous consultation on the proposals 47,000 people had their say in what was a record response total for a UK road scheme. A new consultation period on the latest designs for the improvements begins today and will run for ten weeks until December 20.
Jones has predicted the number of responses to the ten-week consultation to be “in the thousands”.
Approximately 25 public information events are set to be held across Kent and Essex, as well as 30 visits to local communities where people will be able to put any questions directly to the project team.
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