And the route will almost halve the morning peak average journey times between M25 junctions 1b and 31 from nine minutes to just five, Highways England said.
Under the latest designs, the whole route of the Lower Thames Crossing will be a three-lane dual carriageway rather than two lanes in some sections.
This will result in a 90 per cent increase in capacity for traffic crossing the Thames east of London, compared with around 60 per cent – 70 per cent under the previous two-lane plan.
The scheme’s budget has risen to a range of £5.3 billion to £6.8 billion due to more detailed design work and ground investigations. A previous estimate put the range at £4.4 billion to £6.2 billion.
The design has been updated to “minimise the impact on local communities and environment”, Highways England said.
Other changes in the latest designs include:
A new rest and service area to the west of East Tilbury
Removal of the proposed Tilbury link road to reduce traffic on the local road network
Lowering the road by up to six metres in places to reduce its visual impact
Campaign for Better Transport said: “The revised Lower Thames Crossing plans go out for consultation today. We think a better and less expensive, solution would be to expand port capacity north of the Thames, improve freight and passenger rail links across the river, and use distance-based lorry road user charging.”
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.”
The scheme’s project director, Tim Jones, said: “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 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.
“It would almost double road capacity across the Thames cutting congestion, significantly easing pressure at the Dartford Crossing and boosting the resilience of the whole road network. This consultation is an important opportunity for people to share their views on our proposals and I urge anyone who has an interest to have their say.”
The preferred route was announced last April by Mr Grayling.