The following various sections of public roads shall respectively be adopted by the Commonwealth as a State highway to be constructed, reconstructed and maintained at the expense of the Commonwealth under the provisions of present or future laws governing State highways, except as hereinafter provided:

Beginning at a point in the City of Pittsburgh on California Avenue at its intersection with Island Avenue, thence over California Avenue (Ohio River Boulevard) to the intersection of California Avenue and Ohio River Boulevard, thence by way of Ohio River Boulevard through the City of Pittsburgh, Borough of Bellevue, Avalon Borough, Ben Avon Borough, Emsworth Borough to the dividing line between Emsworth Borough and Kilbuck Township, thence over a county road known as Beaver Road to the dividing line of Kilbuck Township and Glenfield Borough, thence over Beaver Road in Glenfield Borough to a point in Glenfield Borough at the foot of Agnew's Hill where Beaver Road intersects Ohio River Boulevard, thence by way of Ohio River Boulevard through the Boroughs of Glenfield, Haysville, Osborne, Sewickley and Edgeworth to Edgeworth Lane in Edgeworth Borough, thence by way of Edgeworth Lane in Edgeworth Borough to its intersection with Beaver Road in Edgeworth Borough, thence by way of Beaver Road in the Boroughs of Edgeworth and Leetsdale to the dividing line between Allegheny County and Beaver County at the intersection of Beaver Road and State Route No. 641, being approximately 13.5 miles in length.