The board may grant franchises along and over the public roads and highways for all lawful purposes, upon such terms, conditions, and restrictions as in its judgment are necessary and proper, and in such manner as to present the least possible obstruction and inconvenience to the traveling public.

Any general law applicable to the granting of franchises by municipal corporations and counties throughout the State for purposes involving the furnishing of any service or commodity to the public or any portion thereof shall be complied with in the granting of any franchises by the board of supervisors.