The 17-mile Interstate 70 to PA Route 51 Project opened on April 12, 2002, creating the longest continuous stretch of the growing Mon/Fayette Expressway and bringing the highway system into Allegheny County for the first time. This 24-mile section of Turnpike 43 extends north from PA Route 88 in Centerville Borough, Washington County to Route 51 in Jefferson Hills Borough, Allegheny County. It includes the six-mile California Toll Road, opened on October 12, 1990; and four miles north from I-70 (Exit 36) to Donora, Charleroi (Exit 39), opened on May 11, 2001.

Travelers can enter and exit at I-70 (Exit 36), S.R. 2025 (Donora, Charleroi - Exit 39), PA Route 136 (Monongahela, Eighty Four Þ Exit 44), S.R.1006 (Finleyville, West Elizabeth - Exit 48), and from Jefferson Boulevard via Route 51 (Exit 54).

Fare collection devices are located at the interchanges with Coyle Curtin Road, Route 136 and Finleyville-Elrama Road for drivers entering the southbound lanes or exiting the northbound lanes. All other traffic is tolled at the mainline plaza in Jefferson Hills. Dual-height, automated machines are utilized at all fare collection points between I-70 and Route 51. Machines accept $1 and $5 bills and commercial cards issued by the Pennsylvania Turnpike Commission. They also issue change and receipts.