Whenever any Federal agency or department has designated any State highway or section thereof as essential to National defense the secretary may upon request of the United States military or naval authorities, with the approval of the Governor, take over for construction, reconstruction, maintenance or repair any bridge, viaduct and other structure upon, over, or appurtenant to, said State highway in any city of the third class, borough, incorporated town or township in the Commonwealth.

The cost and expense of the construction, reconstruction, maintenance and repair of said bridges, viaducts and appurtenant structures shall be paid in whole out of any moneys appropriated to the department or in part with the same moneys and any other funds appropriated to the Commonwealth by the Federal government for any highway purpose.