The project will see upgrades carried out along a series of motorways and A road between 2015 and 2021.
The work is part of the Government's 'Road Investment Strategy' to triple levels of spending on roads by the end of the decade.
Work will begin on 24 new major projects by 2020, in addition to upgrades already underway on the M3, A21 and M25 at junction 30.
Improvements over the next five years will include:
• enhancing capacity on the M3 between Winchester and Southampton
• enhancing capacity on the M27 between Southampton and Fareham
• upgrading the M20 near Maidstone to a smart motorway
• upgrading the M4 to a smart motorway between Reading and the M25
• tackling congestion on the A21 between Tonbridge and Pembury
• upgrading the A27 in Sussex
• improving junctions on the A2 near Bean and Ebbslfeet
-- Advertisement --
• improving the A34 between the M4 and M40
• increasing capacity on the M2 between Sittingbourne and Maidstone
• improving junctions on the M3 near Winchester
• improving the M27 and M271 near Southampton
• tackling delays on the A31 near Ringwood in Hampshire
• improving access to the A12 and A3 from the M25
• upgrading the M25 to the latest generation of smart motorway, with five lanes between the M40 and Chertsey
• developing plans to reduce congestion on the A3 near Guildford
• developing plans for an additional Lower Thames Crossing
Highways England said maintaining the existing road network is also a top priority, with £200m being invested in maintenance this year.
Over 18,716 metres of safety barrier and fencing will be replaced or maintained on the programme, along with 7070 road lights.
In total, 91 out of 171 road signs will be replaced.
The government-owned company also wants to make the roads safer, reducing road casualties by 40% by 2020.
Simon Jones, south east regional director at Highways England, said: "Around 8.7 million people live and work in South East England, more than any other region, and our 932 miles of major roads are some of the busiest in Europe. The M25 alone is used to make an estimated 1 million journeys every day. We're delivering £2.2 billion investment in improvements to the South East's motorways and major A roads over the next five years.
"That includes nearly 150 miles of extra lanes, new junctions, and measures to tackle congestion, benefitting businesses, local residents and road users as well as delivering a fourfold return on investment for the UK economy.
"It's vital that we continue to improve the existing road network as well, which is why we're investing over £200 million this year alone in resurfacing, improving technology and safety measures and other maintenance projects."
(LM/CD)
