Improvements planned for the A21 have moved one step closer to being under way as the company that will be heading a major development has been announced.

Constructor, Balfour Beatty will be in charge of the £69.7m scheme improving the stretch between Tonbridge and Pembury.

A 2.5 mile section will be upgraded from single to dual carriageway, adding a lane in each direction, upgrading junctions and improving the overall road layout.

See a video of improvements below.

Work is expected to start this autumn with main construction starting in spring 2015.

As part of a recorded investment of £24bn by 2021 by the Government towards road improvements, the scheme aims to make journeys on the A21 safer and more reliable.

Roads minister Robert Goodwill said: “Additional capacity on roads is vital for the four million drivers that use our motorways and major trunk roads each day.

"This will boost the local economy and is part of the Government’s biggest programme of road enhancements since the 1970s.”

"This will boost the local economy and is part of the Government’s biggest programme of road enhancements since the 1970s” - Robert Goodwill

The announcement follows successful completion of statutory planning procedures, which means that no further legal objections can be made to plans.

The upgrade is one of six major road schemes that the Highways Agency is developing for delivery after 2015.

Highways Project Manager Graham Link said: “This scheme will improve journeys on the A21 by reducing congestion and improving safety for the 35,200 drivers that use this section each day.

"The A21 is a vital link between London and Hastings as well as connecting local towns.

"Providing better infrastructure will help the local and national economy, helping to support businesses and creating jobs.”

MP for Tunbridge Wells, Greg Clark said the announcement is a big milestone for the A21 dualling.

He added: "Although the Secretary of State for Transport gave the go-ahead in May, there was always the chance that someone might decide to mount a legal challenge, which would have halted progress.

"The fact that no challenge has been made is a huge relief, and reflects the overwhelming case for the dualling that we have made. We can now look forward to seeing work beginning on site from this Autumn.”

At a public enquiry held last year, evidence showed that journey times will be improved by up to 65% in 2016 and the number of collision reduced by 60% along this section.

Stephen Tarr, Balfour Beatty managing director for major projects, said: “We are delighted to have been awarded this contract to upgrade the A21.

"Balfour Beatty has a strong track record of delivering major road schemes both nationally and in the region on time and to budget.

"Our commitment to building sustainably, engaging with local stakeholders, and employing a local supply chain is key to our success and we aim to leave a lasting legacy as a thoughtful contractor behind us.”