S.C. Code § 57-5-820
As used in this section and Section 57-5-830:
"Structurally deficient" means not adequate to handle the vehicle weights authorized on roads leading to them.
"Functionally obsolete" means narrow clearances or sharp roadway approach angles that make passage difficult or hazardous, or with too few lanes for existing traffic needs.
All work to be performed by the Department on state highways within a municipality must be with the consent and approval of the proper municipal authorities, except that work performed or to be performed on a bridge and its approaches, certified by the Department as functionally obsolete or structurally deficient, to remove, replace, or improve such bridge and its approaches shall not require prior consent and approval of a municipal authority if the bridge crosses the intracoastal waterway.
S.C. Code § 57-5-820