A. | Access from individual lots within a subdivision onto an arterial road shall be prohibited. Frontage roads are not encouraged but may be considered when special circumstances exist. |
B. | Driveway spacing and sight distance requirements shall be in accordance with SDDOT standards. |
C. | Minimum width of paved surface shall be 24 feet of 4/8 asphalt paving/base and 2-foot gravel shoulders. Ditches shall have a maximum 4:1 side slope. Additional lanes may be required for higher traffic roadways as determined by the County Engineer. Minimum paved surface radius within a cul-de-sac shall be 30 feet, plus a two-foot gravel shoulder. |
D. | At a minimum, there shall be an eight inch granular base course with a 4-inch asphalt surface for a residential development and a 12 inch granular base course with a four inch thickness of asphalt for a commercial or industrial development. Alternative surface standards may be approved with a submitted professional engineering report. |
E. | Culverts under roadways and driveways shall be reinforced concrete pipe Class II, or higher as needed. Flared or sloped end sections are required on all culverts within the road right-of-way. Minimum driveway culvert size is 18 inches. |
F. | The size of culverts shall be determined by a drainage study for the affected watershed area. |
G. | A cross slope (crown) shall be provided on all roads at a rate of 0.03 feet per foot. |
H. | The road ditch depth shall accommodate drainage volumes, but shall be at least two and one- half feet below the road grade. Alternative ditch depths may be approved where warranted. |
I. | Seeding of ditches and other erosion protection measures shall be employed after grading is completed to minimize erosion. |
J. | Private roadways shall be indicated on the plat and shall not be included as part of any required lot area or setback. |
K. | Any private roadway approved by the county shall provide permanent unobstructed access to the area it serves. The erecting of any structure within the private roadway easement which would in any way interfere with the use of such private roadway by the public or any governmental agency will not be permitted. |
L. | Any plat presented for approval which shows a private roadway as a means of access shall provide language in the owner’s certificate in accordance with § 152.141 reserving the private road for permanent unobstructed access to abutting property and establishing private responsibility for maintenance of the roads. |
M. | Road standards for commercial or industrial developments may be increased by the Planning Director and Highway Superintendent. An increase of these standards will be based on relevant information such as a municipality’s comprehensive plan or subdivision regulations, driveway access widths, speed limit, number and types of vehicles using the road, parking availability, sound engineering judgment, and any other pertinent information. |
N. | In order to maintain consistent signage throughout the county, sign type, and locations shall be included with the final subdivision plans. Signs shall be installed in accordance with the
Manual of Uniform Traffic Control Devices (MUTCD) as amended by county specifications. |
(Ord. 1104-63, passed 4-26-2011; Ord. 1806-38, passed 6-26-2018)