The board of county commissioners of each county, in relation to roads and bridges, shall have the power and it shall be its duty to:

(1) Acquire in the manner provided by law property real and personal and acquire or erect structures necessary for the administration of the county roads of such county;

(2) Maintain a county engineering office and keep record of all proceedings and orders pertaining to the county roads of such county;

(3) Acquire land for county road purposes by purchase, gift, or condemnation, and exercise the right of eminent domain as by law provided for the taking of land for public use by counties of this state;

(4) Perform all acts necessary and proper for the administration of the county roads of such county as by law provided;

(5) In its discretion rent or lease any lands, improvements or air space above or below any county road or unused county roads to any person or entity, public or private: PROVIDED, That the said renting or leasing will not interfere with vehicular traffic along said county road or adversely affect the safety of the traveling public: PROVIDED FURTHER, That any such sale, lease or rental shall be by public bid in the manner provided by law: AND PROVIDED FURTHER, That nothing herein shall prohibit any county from granting easements of necessity.