Highways England have revealed new plans for the Lower Thames Crossing, with a range of improvements it claims will boost capacity by 90%.
The original plans, announced last year, were expected to provide a 70% capacity increase.
Journey times at the Dartford Crossing could be halved if the new road goes ahead as planned, says Highways England.
A new, ten-week consultation on the latest designs for the improvements starts today (Wednesday October 10) and will run until Thursday December 20.
The multi-billion pound road project is set to be the most ambitious since the M25 opened 30 years ago and will include the UK’s longest road tunnel.
The improved proposals published today include:
Making the whole route a three-lane dual carriageway to improve traffic-flow
A new rest and service area to the west of East Tilbury
A new design for the Tilbury junction, removing the proposed Tilbury link road to reduce traffic on the local road network
An improved junction with the A2
The 14.5 mile route connecting Gravesham in Kent and Thurrock in Essex is expected to reduce traffic at Dartford by 22% with 14 million fewer vehicles using it every year. It will almost halve the morning peak average journey times between M25 junctions 1b and 31 from nine minutes to just five.
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.”
Tim Jones, project director for Lower Thames Crossing, added: “For too long the Dartford Crossing has been the only way to get across the Thames east of London. It is a vital gateway, but carries more traffic than it was ever designed for and drivers there suffer from regular delays, severing communities and holding back economic growth.
The project will create a new, three-lane dual carriageway connecting the M2 near Rochester and the M25 in Essex between North and South Ockenden. It would include a 2.4 mile-long tunnel under the Thames between Gravesend and Tilbury – the longest road tunnel in the UK – and, at more than 50 feet wide, the third largest bored tunnel in the world.