PA ROUTE 51 TO I-376 of the Mon Fayette Expressway

Map For more detail on the southern section plans, click here.


The PA Route 51 to I-376 Project is the final and the largest of the four Mon/Fayette Expressway (Turnpike 43) projects. The first three Mon/Fayette projects which have been built stretch 54 miles and connect I-68 in West Virginia to PA Route 51 in Jefferson Hills, Allegheny County.

The funding availability for the PA Route 51 to I-376 Project required it to be divided into two sections: north of the Monongahela River and south of the Monongahela River. The first to be constructed is south of the Monongahela River, which is an eight-mile stretch between PA Route 51 and PA Route 837 and includes the areas of Jefferson Hills, West Mifflin, Dravosburg, the City of Duquesne and the City of Clairton.

The PA Turnpike Commission (PTC) is still acquiring the property interests needed to construct the southern section of the PA Route 51 to I-376 Project. That process is nearing completion, and roadway construction is anticipated to begin in 2022.

Utility work is expected to begin in May of 2021. Duquesne Light Company will begin relocating its transmission lines as part of its agreement with the PA Turnpike Commission. That work is expected to be finished in March of 2023.

Due to the size and scope of the project, roadway construction has been broken into seven sections. As each section is completed, it will be opened to traffic. Construction costs for the entire southern section are estimated to be approximately $680 million with an overall total cost of $1.01 billion which includes the design work, utility moves, tolling equipment and other items.

The Mon/Fayette PA Route 51 to I-376 Project began when the Environmental Impact Statement (EIS) was approved in December 2004. Design then started in 2004 but was halted in 2009 due to lack of funding. In 2013, Act 89 provided funding which allowed the project to restart. In 2015, the PTC performed studies to identify how the originally designed project could be modified and completed with the funding available through Act 89.

Studies showed eliminating the west leg of the original project that led into Pittsburgh would substantially reduce the project cost. This also reduced residential and business displacements. This updated information was added to the EIS, which was approved in 2019, and reduced the scope of the original project.

When construction of the entire 14-mile PA Route 51 to I-376 Project is complete, the Mon/Fayette Expressway will stretch 68 miles from I-68 near Morgantown, West Virginia to I-376 in Monroeville, Allegheny County.