Balfour Beatty has been confirmed as the winner of a £88.6m contract to transform the M4 and M5 near Bristol to a managed motorway.
The managed motorway scheme will cut congestion, make journey times more reliable and improve safety through the use of variable mandatory speed limits and opening the hard shoulder as an extra traffic lane on the M4 between junctions 19 and 20 and the M5 between Junction 15 and Junction 17.
Balfour Beatty will start work between January and March 2012, subject to statutory processes, with the scheme open to traffic in 2013-14.
Roads Minister Mike Penning said: "I welcome today's contract award which confirms that the Highways Agency is on track to start work on this important scheme on time early next year.
"This £88.6 million investment shows the Government is delivering on its promise to invest in transport schemes that reduce congestion, improve safety, and support economic growth.
"At the height of construction hundreds of people will be working on this project that will provide much needed additional capacity for more than 140,000 road users who use these motorways every day.
"Our experience shows that managed motorways deliver significant safety and journey time benefits.
"That's why the Government has committed to start work on 11 managed motorway schemes by 2015, including the M4/ M5, while the Highways Agency is ensuring value for money and making excellent progress against its commitment to reduce the cost of major capital projects by 20 per cent across the roads programme."