(A) Streets.
(1) All streets and alleys shall be completed to grades shown in plans, profiles and cross-sections provided by the subdivider, prepared by a registered professional engineer or registered land surveyor and approved by the Commission. Street width shall be measured from gutter line to gutter line where curbs or curb and gutter are provided.
(2) The streets shall be graded, surfaced and improved to the dimensions shown in approved cross-sections. The work shall be performed as prescribed in Standard Specifications for Road and Bridge Construction and Maintenance, current issue, of the State Highway Commission.
(3) The arrangement, character, extent, width, grade and location of all streets shall be correlated to existing and planned streets, existing topography, public convenience and safety and in their appropriate relation to the proposed use of the land to be served by such streets.
(4) No major subdivision shall be constructed off of a non-paved or gravel road. (See Comprehensive Plan Chapter VI Land Use Patterns).
(5) Base blacktop shall be installed prior to 20% completion of the subdivision and the final surface shall be laid out before 80% completion of the subdivision. Sidewalks may be built along with construction of houses until 75% of the houses have been built, and then the sidewalk must be completed throughout the development.
(6) Minor streets shall be laid out so that their use by through traffic will be discouraged.
(7) Where a subdivision abuts or contains an existing or proposed thoroughfare, a railroad right-of-way or limited access highway right-of-way, the Commission may require a street approximately parallel to and on each side of such right-of-way at a distance suitable for the appropriate use of the intervening land, as for park purposes in residential districts or for commercial or industrial purposes in appropriate districts. Such distances shall be determined with due regard for the requirements of approach grades and future grade separations. The Commission may require that control of said intervening land strips be dedicated to the county or to participating cities or towns under conditions approved by the Commission. The said strips shall be maintained by the involved governmental unit from the date of dedication.
(8) Where a subdivision abuts or contains an existing or proposed street as shown in the Major Thoroughfares Plan, the Commission may require marginal access streets; reverse frontage with screen planting contained in a non-access reservation along the rear property line having a minimum width or ten feet; deep lots with rear service ways, or such other treatment as may be necessary for adequate protection of residential properties and to afford separation of through and local traffic.
(9) (a) A tangent at least 100 feet long shall be introduced between reverse curves on major, secondary and collector streets.
(b) All minor streets shall have a tangent of at least 50 feet long on reverse curves.
(10) (a) Half-streets and half-alleys shall be prohibited.
(b) Whenever a half-street is adjacent to a tract to be subdivided, the other half of the street shall be platted within such tract.
(B) Alleys.
(1) Alleys shall be provided in commercial and industrial districts except that the Commission may waive this requirement if other provisions are made for service access, such as off-street loading, unloading and parking consistent with and adequate for the uses proposed.
(2) Alleys shall be discouraged in residential areas except where topographical or other conditions may necessitate their use.
(3) (a) Alley intersections with sharp changes in alignment shall be avoided, but where necessary, corners shall be cut off sufficiently to permit safe vehicular movement.
(b) Minimum radius at street intersections shall be 20 feet.
(4) Dead end alleys shall be prohibited except when provided with a 40-foot outside turning radius at the dead end.
(C) Additional design standards.
(1) In addition, streets and alley design standards shall conform to the requirements of Tables 4-1, 4-2 and 4-3 as shown on the following pages.
(2) Refer to Figure 4-1 below for a graphical interpretation of a street design section.
Figure 4-1: Street Design Section
Table 4-1
STREET DESIGN STANDARDS
TYPE OF STREET | DESIGN STANDARDS | ||
ARTERIAL, MAJOR, MINOR AND LOCAL COLLECTORS | Plans, profiles and cross-sections in accordance with the road classification or as determined by the Commission | ||
Development Density | |||
Low | Medium | High | |
TYPE OF STREET | DESIGN STANDARDS | ||
ARTERIAL, MAJOR, MINOR AND LOCAL COLLECTORS | Plans, profiles and cross-sections in accordance with the road classification or as determined by the Commission | ||
Development Density | |||
Low | Medium | High | |
Residential Collector (Arterial/Major): | |||
Minimum centerline radius | 350 | 350 | 500 |
Minimum sight distance (ft.) | 300 | 300 | 300 |
Pavement width (ft.) (min. 12 ft. lanes) | 24 | 24 | 24 |
Right-of-way (ft.) (min.) | 60 | 70 | 80 |
Sidewalk distance from curb face | 10 | 10 | 10 |
Sidewalk width (ft.) | 5 | 5 | 5 |
Type of curb (V- vertical face) | V | V | V |
Residential Collector (Minor/Local) | |||
Alley right-of-way and pavement width (ft.) | 25/12 | 30/16 | 50/20 |
Maximum cul-de-sac length (ft.) | 800 | 600 | 500 |
Maximum grade | Level 8%, Rolling 10% | 8% | 8% |
Minimum centerline radius (ft.) | 250 | 350 | 350 |
Minimum cul-de-sac curb radius (ft.) | 40 | 40 | 40 |
Minimum cul-de-sac radius (right-of-way ft.) | 50 | 50 | 50 |
Minimum grade | 0.5% | 0.5% | 0.5% |
Minimum sight distance (ft.) | 200 | 200 | 300 |
Pavement width (ft.) (traveled way) (1) | 20 | 24 | 24 |
Right-of-way (ft.) | 50 | 60 | 60 |
Sidewalk distance from curb face (ft.) | 0 or 4 | 4 | 6 |
Sidewalk width (ft.)* | 4 | 5 | 6 |
Type of curb (2) V-Vertical face R-Roll type O-None | O | R | R |
* Installation of paved sidewalks on at least one side of the street shall be required, in all major subdivisions. the park, railroad or other uses makes a sidewalk non-essential. (See § 153.108 for sidewalk improvements.) NOTE: Pavement widths are measured from face of gutter to face of gutter (or from the edge of the travel lane to the edge of travel lane.) (1) On street parking - Increase ten feet on each side. (2) Per design - Rural areas may use shoulder and open drainage ditches. | |||
TABLE 4-2
INTERSECTION DESIGN STANDARDS
INTERSECTION DESIGN | ALL DEVELOPMENT DENSITIES |
Clear sight distance (length along each approach leg-ft.) | 30 mph = 200 feet 40 mph = 300 feet Others per A.A.S.H.T.D. design |
Minimum angle of intersection | 80 degrees (90 degrees preferred) |
Minimum centerline offset of adjacent intersections (street jogs-ft.) Arterial/major collector Local collector Minor collector | 300 feet 150 feet 200 feet |
Minimum curb radius (ft.) Arterial/major collector Local collector Minor collector | 50 feet 25 feet 40 feet |
Vertical alignment within area | 2% maximum |
TABLE 4-3
DESIGN CHARACTERISTICS OF STREET AND ALLEY PAVEMENTS
PAVEMENT TYPE AND MATERIALS* | ARTERIAL/MAJOR COLLECTOR | MINOR COLLECTOR | RURAL/LOCAL COLLECTOR | ALLEY |
PAVEMENT TYPE AND MATERIALS* | ARTERIAL/MAJOR COLLECTOR | MINOR COLLECTOR | RURAL/LOCAL COLLECTOR | ALLEY |
Flexible | ||||
HMA asphalt - base or compacted Aggregate (#53) | 12 in. | 8 in. | 8 in. | 6 in. |
HMA asphalt - intermediate | 2-1/2 in. | 2-1/2 in. | 2-1/2 in. | 0 |
HMA asphalt - surface | 1-1/2 in. | 1-1/2 in. | 1 in. | 1-1/2 in. |
Total thickness** | 16 in. | 12 in. | 11-1/2 in. | 8 in. |
Rigid
| ||||
Portland cement concrete | 8 in. | 7 in. | 6 in. | 6 in. |
Sub-base (aggregate) | 4 in. | 4 in. | 4 in. | 4 in. |
Total thickness | 12 in. | 11 in. | 10 in. | 10 in. |
* Materials per current State Department of Transportation specifications and interim specifications. ** Roadway section to be constructed on approved compacted sub-grade. | ||||
(Ord. 2, passed 8-14-2006) Penalty, see § 10.99