(A) Arterial streets. The arrangement of arterial streets in a subdivision shall conform to the official street map and provide for the continuation or projection of existing streets in adjacent areas; or conform to a plan approved by the Planning and Zoning Commission where topographic or other conditions make continuance or conformance to existing streets impracticable.
(B) Collector streets. Collector streets shall be properly related to arterial streets and designed in a manner so as to supplement the arterial street system, but not serve in lieu thereof.
(C) Local streets. Local streets shall be designed to benefit from the topography, to discourage through traffic and to provide the minimum amount of streets necessary for safe access to adjacent properties. The use of curvilinear and cul-de-sac streets may be allowed where necessary, but are to be discouraged.
(D) Frontage road. Where the subdivision abuts upon, or contains an existing or proposed highway, major thoroughfare or railroad right-of-way, the Planning and Zoning Commission may require reverse frontage lots with appropriate screening/plantings in the non-access roads parallel to and on either side of the highway, major thoroughfare or railroad right-of-way providing access to adjacent properties and affording separation of through and local traffic.
(E) Alleys.
(1) (a) Dead-end alleys are prohibited, except where natural or other features makes it impossible to avoid.
(b) Where dead-end alleys are unavoidable, they shall be provided with adequate turnaround facilities at the dead-end as determined by the City Engineer.
(2) Alleys shall not be permitted in any residential areas unless a secondary means of access to certain property is necessary due to topography or other exceptional circumstances.
(F) Minimum street design table. Streets shall be designed to meet the minimal standards established in the table below.
Street Type | Rights- of-Way | Surface Width | Minimum Horizontal Curve Radii | Minimu m Tangent Between Curves | Minimum Grade | Maximu m Grade | |
Street Type | Rights- of-Way | Surface Width | Minimum Horizontal Curve Radii | Minimu m Tangent Between Curves | Minimum Grade | Maximu m Grade | |
Curb and Gutter | Open Ditch
| ||||||
Arterial | 80 feet | 44 feet | 48 feet | 850 feet | 200 feet | 0.4% | 5% |
Collector | 66 feet | 36 feet | 24 feet | 400 feet | 150 feet | 0.4% | 7% |
Local street in residential subdivision | 66 feet | 36 feet | 24 feet | 200 feet | 100 feet | 0.4% | 10% |
Local street in commercial subdivision | 100 feet | 100 feet | 7% | ||||
Local street in industrial subdivision | 400 feet | 150 feet | 5% | ||||
Alley | 30 feet | 20 feet | 20 feet | 200 feet | 100 feet | 0.4% | 10% |
Base and pavement specifications: As specified by the City Engineer and City Council; in mixed use districts, use the most restrictive standard. Minimum standard shall be 4" bituminous pavement, 8" aggregate base, 12" of granular base | |||||||
(G) Cul-de-sacs.
(1) Proposed streets designed to have one end permanently closed shall not exceed 400 feet in length, except where the City Engineer has approved additional length due to property limitations or large lot size.
(2) Cul-de-sac development is discouraged and will only be considered as an exception, such as due to topography.
(3) Turnarounds shall be provided at the permanently closed end of all streets and shall have a minimum right-of-way radius of 60 feet and a minimum radius of 48 feet to face of curb.
(4) For phased developments or any streets with a temporarily closed end, turnarounds shall be provided with a turning radius as determined by the City Fire Chief.
(H) Open ditch street design.
(1) In areas of the city where geographical and topographical characteristics exist that would not be economically or feasibly served by standard subdivision criteria, the city may allow or require larger, more spacious lots and allow or require these areas to be served by an "open-ditch" street design.
(2) The following improvements will be required for all open ditch street sections within the corporate limits of the city:
(a) Water and sanitary sewer services must be extended to a point equal to or beyond the top of ditch backslopes;
(b) Surface drainage facilities and appurtenances as required by the City Engineer. All driveway drainage structures must be designed to a Q50 standard. All public street drainage structures must be designed to a Q100 standard;
(c) Aggregate base as required by the City Engineer. Minimum standards are ten inches compacted base finished to a width of 28 feet;
(d) Roadway surface of bituminous or concrete. Minimum standards are four inches compacted with a total surfaced width of 24 feet;
(e) Ditch sections to be approved by the City Engineer. Minimum standards are two-foot ditch, six-foot wide bottom and inslope/backslope grade not greater than four to one; and
(f) Seeding, mulching and sodding or other restoration as required by the City Engineer.
(Ord. 879, passed 10-28-2020)