A $1.3 billion expansion project of the Pennsylvania Turnpike’s Mon-Fayette Expressway between Route 51 and Interstate 376 is expected to get underway soon, according to the Turnpike Commission.

The 8-mile extension will expand the Mon-Fayette Expressway, which now stretches 54 miles from Jefferson Hills to Morgantown, W.Va. When complete, the Mon-Fayette Expressway will stretch north to the Parkway East in Monroeville, with the new extension running through the Turtle Creek valley.

The project also hopes to link the Southern Beltway to the Parkway East in Monroeville — stretching through southern Allegheny County to provide an alternate, tolled route between the county’s eastern and western ends.

The turnpike commission awarded its first bid for the southern section of the Mon-Fayette extension to Pittsburgh-based Trumbull Corp. The $214 million contract will have Trumbull construct a 3.1-mile section of highway from Clairton through Jefferson Hills to West Mifflin.

That work is part of the larger, $1.3 billion project that will create 8 miles of new highway, with two lanes in each direction.

“This long-awaited project represents a significant investment in the Mon Valley that will not only enhance mobility in the area but is expected to bring economic opportunities to the region,” Pennsylvania Turnpike Commissioner Sean Logan in a statement.

The Mon-Fayette extension project has come under scrutiny over the years as it has faced several delays and criticism that it won’t carry enough vehicles to justify its high cost. Supporters of the project have said it will provide a needed economic boost to hard-hit towns in the Mon Valley.

The Turnpike Commission expects the portion of the extension from Jefferson Hills to Duquesne to take six years to complete. There is no timeline yet for the rest of the project from Duquesne to Monroeville, nor the connection to the Mon-Fayette’s connection to the Southern Beltway. Funding comes from Act 89 of 2013, the state’s last large transportation funding bill.

Turnpike Chief Engineer Brad Heigel said motorists will be able to drive on sections of the Mon-Fayette extension as they are completed.

A public meeting on the project is expected to be held in February. Details on the meeting will be released.

Ryan Deto is a Tribune-Review staff writer. You can contact Ryan by email at rdeto@triblive.com or via Twitter .