Work is expected to begin later this year on the project, following an announcement by Transport Scotland that the number of firms bidding for the £415million contract has been whittled down to two.
The plan will see upgrades to the M8, M73 and M74 motorways.
The firms battling for the work have been named as Connect Roads and Scottish Roads Partnership.
This is the first roads infrastructure scheme to be procured as part of a £2.5billion Scottish Government plan.
The project will complete the motorway between Glasgow and Edinburgh by upgrading the A8 between Baillieston and Newhouse, creating a full three-lane motorway.
It also includes work to improve Raith Interchange and the widening of key sections of the M8, M73 and M74.
When it opens in 2017, the new section of road will take up to 18 minutes off journeys at peak times, claims Transport Scotland.
It is also expected to directly support hundreds of jobs, as well as many more in the supply chain.
Deputy First Minister Nicola Sturgeon said: "On completion the M8, M73, M74 Motorway Improvements Project will boost the nation's economy by improving connections between the commercial centres of Glasgow and Edinburgh and beyond. Since the start of the year we have announced major progress on four trunk road construction projects.
"Today again we are taking another step in the delivery of a critical construction contract.
"Completing the M74 directly supported 900 construction jobs and we expect this project to be of a similar scale.
"On-the-job training for apprentices and local employment opportunities will be a key feature of this £415m project, with the successful contractor required to provide community benefits.
"This project will deliver lasting benefits."
Transport Scotland also intends to award a £3.1m groundworks contract to Forkers Ltd. The first of a series of advance works for the scheme, it is expected this work will be completed in the summer.