The following are hereby adopted as the minimum standards of design of a subdivision. In addition, all subdivisions shall conform to all applicable elements of the city's land use plan including any change in these standards which is indicated by any applicable plan elements. The arrangement, character, width, grade, and location of all streets shall conform to the city's highway system or plans for the opening, widening, or extension of any street, road or major thoroughfare as adopted by the City Council in the public interest. Whenever a tract to be subdivided includes any part of such thoroughfares as approved or shown on the adopted land use plan, such part shall be dedicated to the public for street purposes by the developer.
(A) General requirements.
(1) Interpretations. In order to promote the best possible development and use of land, the Commission shall interpret the standards, provisions, and specifications contained in this chapter liberally and in favor of the community's interest. Exceptions from these standards, provisions, and specifications may be granted when shown conclusively and to the satisfaction of the Commission that such exceptions will bring about a more logical and desirable result than would be obtained by strict compliance. When in doubt as to the wisdom of granting such an exception, the Commission shall request a decision from the full Commission.
(2) Land subject to inundation. Land subject to flooding according to the Department's flood maps shall comply with the city's, or other applicable, flood plain ordinances. The developer or his agent shall submit information adequate to prove that lots or portions of lots are not subject to flood hazard.
(B) Streets and alleys.
(1) Continuation of existing streets. Proposed streets shall, as nearly as practicable, provide for the continuation, connection, or projection of streets in surrounding areas; or may conform to a plan for one of the municipality's neighborhoods as may have been prepared by the Department and adopted by the City Council.
(2) Circulation. The street pattern shall provide ease of circulation within the subdivision, but the local streets therein shall be so laid out that their use by through traffic will be discouraged. New street openings shall be generally prohibited within 600 feet of any major intersection or crossing, such as: those formed by a railroad and a highway; two or more arterial streets; or from the head of any major bridge, grade separation structure or like facilities, as measured along the center line from the intersection or from such structures.
(3) Topographical and cultural features. In sloping terrain, streets shall generally run parallel to the contour of the land or preferably cross at a slight angle therewith. The general objectives are to avoid steep street grades, heavy concentrations of storm surface runoff, abnormal differentials in building elevations at opposite sides of the street, and excessive grading operations. Appropriate treatment shall be given to encourage the preservation of existing views, wooded areas, creeks, and other attractive natural features of the plat.
(4) Portion of tract. Where the plat to be submitted includes only a part of the tract owned by the developer, the Commission shall require topography and a sketch layout of the future street system on the unsubdivided portion.
(5) Relocation to major streets. Where a subdivision abuts or contains an existing or proposed arterial street, the Commission may require marginal access streets, or a reverse lot frontage with screen planting or masonry wall contained in a non-access reservation along the rear property line, and such other treatment as may be necessary for adequate protection of the proposed industrial, commercial or residential development. Before requiring any marginal streets or reverse frontage arrangements, the Commission shall take into account and decide upon the physical location of the major public utility lines as they relate to the existing and potential development along both sides of the street.
(6) Frontage along railroads. Where a subdivision borders on a railroad right-of-way, the Commission may require a street approximately parallel to the side of such right-of-way, and at a reasonable distance therefrom, dependent on the nature and intended use of the subdivision. Such distance shall also be determined with due regard for the requirements of future grade separation facilities and access roads or ramps thereto.
(7) Street intersections. The angle of intersection between minor and major streets should not vary by more than ten degrees from a right angle. All other streets should intersect each other as near to a right angle as possible and no intersection of streets at angles of less than 70 degrees shall be permitted.
(8) Street jogs. Street jogs shall be avoided whenever possible. However, where permitted, the centerline offset distance between roads entering a common right-of-way from opposite sides shall not be less than 150 feet.
(a) Half-streets. Half streets shall be prohibited. In case a half street is adjacent to a tract to be subdivided, the other half of the street shall be platted within such tract.
(b) Reserve strips. Reserve strips controlling access to streets shall not be permitted. Streets shall be located on the edge of or one lot depth away from, the boundary of the tract.
(c) Dead-end streets. Dead-end streets are prohibited. However, where it is necessary to provide circulation to undeveloped property adjacent to the boundaries of the proposed subdivision, a temporary cul-de-sac with a turnaround pavement radius of not less than 50 feet shall be provided within the subdivision and adjacent to its limit for what would otherwise be stub-end street. Provision will be made by the developer that when the right-of-way is extended into the adjacent property that portion of the turnaround in excess of the right-of-way width will revert to the adjacent property owner or owners and curbs and gutters will be provided.
(d) Cul-de-sac. Cul-de-sac, designed to be permanent, shall not be longer than 800 feet and shall be provided at the closed end with a cul-de-sac having an outside roadway diameter of at least 100 feet, and a right-of-way line diameter of at least 120 feet.
(e) Alleys. Alleys in residential developments will be prohibited. Service roadways will be required in commercial and industrial developments, except where other provisions for suitable access and off-street loading and unloading is assured. Alleys may be provided at the rear of all lots or tracts intended for multiple-family building use; however, they will not be encouraged.
(f) Right-of-way. In the case of the extension of an existing adjoining right-of-way having a width less than the minimum requirements, the Commission may approve the extension thereof at the same width.
(C) Dimensional standards.
(1) Typical street standard. The Commission and Department will determine the required minimum dimensional standards of all rights-of-way, pavements, sidewalks, and other public improvements but shall consider the advice and recommendation of the city engineer in doing so. The typical street requirements shall be as follows:
(a) Arterial street (urban). The right-of-way width shall be as indicated in the comprehensive plan. As the geometrical design, pavement and right-of-way widths may vary considerably over that of a typical local street, the Commission and Department shall decide upon the pavement width and the portion of the major street construction that shall be done by the developer. In doing so, the Commission and Department shall take into account the location, extent and character of the proposed development, the degree to which the proposed lots or land use is to be serviced from or otherwise has access on the major streets, the number of anticipated employees, and the extent of vehicular traffic that may be generated by such improvements or subdivision upon such major street or streets. The Commission and Department in determining the amount of participation that shall be made by the developer, shall also take into account the cost and participation involved in the trunk sewers and possible extra cost in length of service connections, driveway aprons, etc.
(b) Collector street (urban). Eighty foot right-of-way, 36-foot pavement, including curb and gutters, 5-foot sidewalks near property line. At these dimensions parking shall be allowed on no more than one side of the street.
(c) Local street (urban). Sixty-six foot right-of-way, 30-foot pavement, including curb and gutters, five-foot sidewalks near property line. At these dimensions parking shall be allowed on no more than one side of the street.
(d) Dead-end street (cul-de-sac). Sixty-foot right-of-way, 27-foot pavement. At these dimensions parking shall not be allowed on the street.
(e) Marginal access streets abutting a major street or highway. Sixty- foot right-of-way, 24-foot pavement, plus curbs and gutters. At these dimensions parking shall not be allowed on the street.
(f) Alleys. Sixteen and one half foot right-of-way and pavement with space for utilities. Larger pavement, or right-of-way areas may be required by the Commission, as needed.
(g) Crosswalks. Ten-foot right-of-way, at least five-foot paved walkway along centerline.
(h) Private lane or way. Twenty-four foot paving width. Curbs and gutters and sidewalks are required unless waived by Commission.
(2) Street grades. No street grade shall be less than .5% and shall not exceed the following allowances for vertical curves:
(a) Arterial. Arterial street or arterial highway 5%.
(b) Collector. Collector street or collector highway 5%.
(c) Local. Local streets and alleys, shorter than 500 feet and cul-de-sacs 10%.
(3) Minimum horizontal. Radii of centerline curvature.
(a) Arterial. Arterial streets and highways, 475 feet.
(b) Collector. Collector streets and highways, 300 feet.
(c) Local. Local streets and highways, 200 feet.
(d) Other. Cul-de-sac and dead-end streets, 100 feet.
A tangent at least 100 feet long shall be introduced between reverse curbs on arterial or collector streets and at least 50 feet on local streets.
(4) Visibility.
(a) Vertical. Minimum vertical visibility (measured four and one half foot eye level to 18 inches tail light) shall be:
1. Five hundred feet on arterial streets or highways.
2. Three hundred feet on collector streets and highways.
3. Two hundred feet on local streets and highways.
4. One hundred feet on streets shorter than 500 feet.
(b) Horizontal. Minimum horizontal visibility shall be:
1. Five hundred feet on arterial streets and highways.
2. Three hundred feet on collector streets and highways.
3. One hundred feet on all other streets, as measured on such centerlines.
(5) Intersections. The radii on both pavement edge and right-of-way is to be 25 feet minimum at all points of roadway intersection and 50 feet for industrial or arterial street intersections.
(D) Blocks.
(1) Limitations and opportunities of topography.
(a) Lengths. No block shall be longer than 1200 feet nor less than 500 feet, except in unusual circumstances.
(b) Crosswalks. Where blocks are over 600 feet in length, a cross walk easement not less than 10 feet in width may be required, if necessary, to provide proper access to schools, playgrounds, shopping centers and other facilities.
(c) Commercial/industrial buffers. The depth and width of properties laid out or reserved for commercial and industrial purposes shall be adequate to provide for the off-street parking and service facilities required by the type of use and development contemplated. The permanent reservation of suitable buffer and easement areas may be required, where deemed essential to preserve the character of surrounding neighborhoods. Such areas shall normally be made a part of abutting lots.
(E) Lots.
(1) Size, shape and orientation. The lot size, width, depth, shape, orientation and the minimum building setback lines shall be appropriate for the location of the subdivision and type of development and use contemplated. A length to width ratio of approximately 1 ½ to 1 is considered desirable. Lot depth in relation to width normally shall not exceed a ratio of 2 to 1, especially where the provision of common open space can be accomplished.
(2) Dimensions. Lot dimensions and area shall not be less than the requirements of any existing Zoning Ordinance. In subdivisions not providing full community sewer and water facilities, increased area will be required in instances where such need is indicated by the city and/or county Health Department investigations.
(3) Corner lots. No corner lot shall have a width at the building line of less than 75 feet. Either of the two sides of a corner lot fronting on a street may be designated the front of a lot, provided the rear yard shall always be opposite the frontage so designated. All corner lots, be they at the intersection of the rights-of-way of two streets or of an alley and a street, shall have a curve with a minimum radius of 25 feet joining the two sidelines of said right-of-way.
(4) Lot lines. Lot lines shall be at right angles or radial to the street line or substantially so, and along curved linear street lot lines shall form a lot having not less than 25 feet of width at either the front or rear lot line.
(5) Double frontage lots. All lots shall abut an improved public street or private lane. Double frontage and reverse frontage lots are discouraged, but may be required where they are desirable to provide separation of development from traffic arteries or to overcome other disadvantages of topography or situation. A planting screen easement of at least 20 feet, and across which there shall be no right-of-access, may be required along the line of lots abutting such traffic, artery or other inharmonious use.
(6) Building sites. Every lot shall contain a suitable building site. Lots containing rock formations, water courses, or other adverse conditions, shall have an additional depth or width as required to meet the Zoning Ordinance requirements for "buildable area" for a lot.
(F) Street names. Names of new streets shall not duplicate the names of existing streets of record. New streets that are extensions of, or in alignment with, existing streets shall bear the name of the existing streets. All names shall meet with the approval of the city engineer. Streets shall be named in the following manner unless otherwise permitted at the time of the approval of the preliminary plat.
General Direction Long Short(less than 1000')
North and south Streets Places
East and west Avenues Courts
Diagonal Roads Way
Curving Drives Circles
(G) Easements. Easements shall be provided for any surface, underground, or overhead utility service, including storm water drainage, as required by the applicable utility companies and the Commission. They shall have a total width of 20 feet and shall be established along rear lot lines and along such other lot lines as are required to provide continuity of alignment throughout the area served. When possible, 10 feet shall be taken from each of two adjoining lots for the total 20-foot easement. Larger easements may be required if deemed necessary for the proper installation of utilities. An easement between any two lots located at the end of a cul-de-sac may be required in order to provide for the engineering requirements of water distribution systems.
(H) Resubdividing and replatting. The reviewing Commission or Committee shall, in the performance of its plat-approving function, be vigilant for opportunities to encourage and facilitate the re-platting of prematurely and inexpertly subdivided areas which are now in sharp contrast to current standards of acceptability. Rehabilitation of these areas shall be implemented through proper design considerations when adjacent un-subdivided land is proposed for development.
(I) Business and industrial subdivisions. Business and industrial areas shall be subdivided into lots of such size, shape, and arrangement as to meet business or industrial needs. Properties reserved or laid out for business or industrial purposes shall be large enough to provide for the setback, yard, and off-street parking and loading facilities required by the type of development contemplated and the city's Zoning Ordinance.
(Ord. 8290, passed 12-17-02)