Design and construction requirements.

Charleston, S.C., Zoning Ordinance § 54-1060

in effect

Sec. 54-1060. - Design and construction requirements. 1. Road Design. a. Specific Right-of-Way Information. (1) Causeways: (a) Streets to be constructed on causeways shall meet all of the requirements contained within these specifications and the causeway shall also meet the following requirements: (b) The minimum street centerline elevation at finish grade shall be 6.5 feet above mean sea level. (c) The minimum side slopes shall be 2:1, preferably 3:1 (Horizontal/vertical). (d) The minimum top width of the roadway shall be as defined by the road classification plus six-foot wide shoulders (as measured from the edge of travel way to the face of the guide rail) if SCDOT standard guide rails are constructed. If no guide rails are constructed, nine-foot wide shoulders shall be required on each side of the travel way. (e) The developer shall provide copies of the approved permits or application ID numbers from all applicable regulatory agencies should expanding the causeway roadbed beyond the toe of the original roadbed be required. (2) Bridges: (a) Bridges shall be designed in accordance with the AASHTO Standard Specifications for Highway Bridges, current edition and interims, as well as meet the following requirements: i. Live load: HS 20-44 loading or an alternate military loading, whichever produces the greatest stress. ii. The minimum travel way centerline elevation shall be 6.5 feet above mean sea level. iii. The minimum width of the bridge shall be 24 feet clear roadway width. iv. The minimum clear width for all bridges on streets with curbed approaches should be the same as the curb to curb width of the approaches, but not less than 24 feet clear roadway width. v. For streets with shoulders and no curbs, the clear bridge width preferably should be the same as the roadway width. However, in no case should it be less than 24 feet or the travel way width plus two feet each side, whichever is greater. vi. Pedestrian ways on the approaches shall be carried across all new structures. vii. SCDOT standard guide rails shall be required. viii. All bridges shall be concrete structures supported on concrete piles. ix. The developer shall provide copies of approved permits from applicable regulatory agencies for the construction of bridges. x. The Public Works Director may consider design alternatives to the aforementioned standards. Any request for design alternatives must be submitted in writing and include details and justifications for each requested alternative. Written approval by the Public Works Director of the requested alternative is required prior to proceeding with construction. (3) Temporary Cul-de-sacs: Temporary cul-de-sacs shall be provided when incremental road construction and/or phasing is requested by the developer. Temporary cul-de-sacs shall be constructed as required by this section. Unpaved temporary cul-de-sacs shall require an additional two inches (compacted depth) of base course. b. Pedestrians Ways Within Publicly Dedicated Right-of-Way. (1) When placed within the public right-of-way, pedestrian ways shall be constructed as specified below: (a) Asphalt sidewalk: i. An asphalt sidewalk shall have a minimum asphalt thickness of 1½" inches and a minimum base course thickness of four inches. The minimum width for pedestrian ways shall be four feet. All work, materials, methods, and equipment, unless specified otherwise herein, shall be in accordance with the SCDOT (SS). ii. For additional ADA requirements see Section 54-1060, 1.a(2) Bridges. (b) Concrete sidewalk: A concrete sidewalk shall have a minimum thickness of 4" except at driveways where the minimum thickness shall be 6". Transverse expansion joints shall be placed at intervals of not more than 50'. The minimum width for pedestrian ways shall be 4'. All work, materials, methods, and equipment, unless specified otherwise herein, shall be in accordance with the SCDOT (SS). c. Road Surfaces Types. (1) Earth roads. (a) The City standard earth roadway is identical in cross section to a City standard paved road except that roadbed stabilization may require that material be mixed into the existing soil material, as needed, to a depth of six inches to achieve suitable compaction. The crown shall be six inches. Department of Public Service inspectors will determine whether the prepared subgrade material and earth road overlay soil are acceptable. (b) A suitable soil is required for a minimum depth of 18 inches to provide a street that will serve the traffic needs in extremely dry, normal, and in wet weather. Where necessary, a stabilizing type soil shall be added and properly mixed with the soil in place for a depth of not less than 0.6 inches. (c) Earth roads, when intersecting with an existing paved road, shall have a paved apron extending to the paved road's right-of-way and when intersecting with a rocked road, shall have a rocked apron extending to the rocked road's right-of-way. (2) Rock roads. (a) The City standard rock roadway is also identical in cross section to a City standard paved road except that the subgrade is mixed with a 4" minimum aggregate base course worked into the top 2 inches of the existing subgrade, creating a six-inch deep compacted rock surface, meeting the SCDOT (SS). The road crown shall be a minimum of 6". The rock material shall be crusher-run granite aggregate unless otherwise approved by the Public Works Director. (b) Rocked roads, when intersecting with an existing paved road, shall have a paved apron extending to the edge of the paved road's right-of-way. (3) Paved roads. Shall satisfy the requirements of the Code of the City of Charleston.

Source: City of Charleston, South Carolina, Code of Ordinances and Zoning Ordinance (Municode Library, library.municode.com)URL: https://library.municode.com/sc/charleston/codes/zoning?nodeId=ART10AGZODI_PT4RUROSTAGZODI_S54-1060DECOREFetched: 11/7/2026