72 Pa. Stat. § 3442
The unexpended balances of all appropriations heretofore made, or which may hereafter be made, by the General Assembly to the State Highway Department or the Department of Highways for the same specific purpose, and available for the use of the State Highway Department or the Department of Highways until used as provided in section thirty-nine of the act, approved the thirty-first day of May, one thousand nine hundred and eleven (Pamphlet Laws, four hundred and sixty-eight), entitled "An act providing for the establishment of a State Highway Department, by the appointment of a State Highway Commissioner, two Deputy State Highway Commissioners, chief engineer, chief draughtsman, superintendents of highways, and a staff of assistants and employés; defining their duties and the jurisdiction of the State Highway Department, and fixing salaries of commissioner and deputies and other appointees; providing for taking over from the counties or townships of the Commonwealth certain existing public roads connecting county seats, principal cities, and towns and extending to the State line; describing and defining same by route numbers as the State Highways of the Commonwealth; providing for the improvement, maintenance, and repair of said State Highways solely at the expense of the Commonwealth, and relieving the several townships or counties from any further obligation and expense to improve or maintain the same, and relieving said townships or counties of authority over same; requiring boroughs and incorporated towns to maintain certain State Highways wholly and in part; requiring the State Highway Commissioner to make maps to be complete records thereof; conferring authority on the State Highway Commissioner; providing for the payment of damages in taking of property, or otherwise, in the improvement thereof; providing for purchase or acquiring of turnpikes or toll-roads forming all or part of any State Highway, and procedure therein; providing for work of improvement of State Highways to be done by contract, except where the State Highway Commissioner decides the work to be done by the State; providing aid by the State to counties and townships desiring the same in the improvement of township or county roads; defining highways and State-aid highways; providing method of application for State aid in the improvement, maintenance, and repair of township or county roads, and prescribing the contents of township, county, borough, or incorporated town petitions; providing for percentage of cost of improvement or repairs to be paid by State, county, township, borough, or incorporated town, and requiring contracts by counties, townships, boroughs, and incorporated towns with Commonwealth governing same; providing for the minimum width of State Highways and State-aid highways, and kind of materials to be used in the improvement; providing for payment of cost of improvement and repairs; providing penalty for injuring or destroying State Highways; making appropriations to carry out the provisions of the act; and providing for the repeal of certain acts relating to Highway Department and improvement of roads, and of all acts or parts of acts inconsistent herewith; and providing that existing contracts are not affected by provisions of this act," its amendments and supplements, shall be carried forward to the appropriation for the current biennium and remain to the credit of the State Highway Department or the Department of Highways until expended in accordance with the provisions of the appropriation.
72 P.S. § 3442