36 Pa. Stat. § 478.13
The department shall have the right and the power to acquire by gift, purchase or condemnation such property in fee simple absolute or such lesser estate or interest as the Secretary of Transportation determines is necessary for the construction, erection, maintenance and protection from encroachment of such roadside rests. The power of eminent domain, for the purpose of condemnation of such property in fee simple absolute or such lesser estate or interest as the Secretary of Transportation determines is necessary, shall be exercised in the same manner as is now or may hereafter be provided by law for the condemnation of property in changing widths, lines and locations of State highways. When and if such property is acquired, it shall become part of the highway route on which it is located or to which it is adjacent.
36 P.S. § 478.13