71 Pa. Stat. § 1376
The State Highway Commissioner is hereby empowered to make and adopt rules and regulations for conducting the business and work of the department, not otherwise expressly provided in this act, and to prescribe the duties of all appointees and employés. All appointees or employés of the department shall be subject to removal or discharge by the State Highway Commissioner.
He is hereby authorized and empowered to purchase all machinery, implements, tools, and materials, of any and every kind, incident to or necessary in the construction, building, rebuilding, and maintenance of the State Highways hereinafter described, including the right to employ all necessary labor; and, if in the judgment of the commissioner it is necessary in order to expedite and more efficiently carry out the work of the department, he may purchase and maintain, at the expense of the department, wagons and other vehicles, including horses, mules, and harness, and provide for their keeping and maintenance, which shall be used only in connection with the work of the department.
The State Highway Commissioner is hereby further authorized and empowered to purchase and acquire land or lands, in the name of the Commonwealth and situated anywhere therein, containing stone suitable for use in the construction or maintenance of highways, and to quarry and prepare the stone thereon for use in the construction and maintenance of the State Highways or State-aid highways, and to manufacture any other material used in the construction or maintenance thereof, and to use such stone and material, so quarried, prepared, and manufactured, in such construction and maintenance, or to sell, furnish, and supply the same to contractors engaged in building or maintaining the State Highways or State-aid highways, upon such terms and conditions, and for such price, as he shall deem best for the interests of the Commonwealth.
And he is hereby further authorized and empowered to erect such buildings and purchase such machinery, utensils, tools, and equipment, as may be necessary or essential for the proper prosecution of the work of quarrying and preparing stone and manufacturing material, pursuant to the foregoing provision, for use in the construction and maintenance of State Highways and State-aid highways, and to employ all labor required for the operation thereof.
71 P.S. § 1376