§ 2. Street plan.  


Latest version.
  • (2.1)

    General.

    (a)

    The arrangement, character, extent, location, and grade of all streets shall be laid out according to good land planning principles and shall be integrated with all existing and planned streets. New streets shall consider topographical conditions, orientation to vistas, public convenience and safety, and the proposed uses of land to be served by them.

    (b)

    The proposed street system shall also be coordinated with the street system of the surrounding area. However, the number of streets converging upon any one point which would tend to promote congestion shall be held to a minimum. Creation of street intersections of three (3) or more streets shall not be permitted. The street pattern shall be in conformity with a plan for the most advantageous development of the entire neighboring area.

    (c)

    Sufficient proposed streets shall be provided to create normal circulation of traffic within the vicinity. Land abutting a proposed subdivision shall not be left land-locked by such proposed subdivision. Street design shall provide connections to abutting properties at intervals not to exceed the maximum block length of twelve hundred (1,200).

    (d)

    In addition, if in the opinion of the planning commission it is desirable to provide street access to an adjoining property, said street shall extend by dedication to the boundary of such property. A temporary turn-around, as defined in design standards for street cul-de-sac, shall be provided for these streets. Minor streets shall be so laid out that their use by through traffic in the subdivision will be discouraged.

    (e)

    Subdivisions which about or have included within the proposed area to be subdivided any freeway or major street as shown on the sketch thoroughfare plan, shall be platted in the general location and of the width called for by such plan. In addition, it shall also provide the following:

    (1)

    A marginal access street, or

    (2)

    Reverse frontage with screen planting contained in a non-access reservation along the rear property lines, or

    (3)

    Deep lots with rear service drives, or

    (4)

    Other treatment which may be necessary to provide for the adequate protection of properties, and to afford separation of through and local traffic.

    (f)

    Intersections of minor subdivision streets with major streets shall be held to a minimum.

    (2.2)

    Private reserve strips. Private reserve strips controlling access to streets shall be prohibited.

    (2.3)

    Half-streets. Where there exists a dedicated or platted half-street adjacent to the tract to be subdivided, the other half shall be platted. New half-streets or half-alleys shall be prohibited.

    (2.4)

    Cul-de-sacs. Streets designed to have one end permanently closed shall have a maximum length of six hundred (600) feet and shall be provided at the closed end with a turn-around having a minimum right-of-way diameter of one hundred (100) feet, and a minimum roadway diameter of eighty (80) feet. Where the cul-de-sac is expected to be continued in the future into unsubdivided land, the turn-around may be a temporary one.

    (2.5)

    Street intersections. Street intersections with center line offsets of less than one hundred and twenty-five (125) feet shall not be permitted.

    (2.6)

    Minimum street right-of-way widths.

    (a)

    In developed or vacant area, the planning commission shall have the discretion of identifying or classifying streets. The widths of rights-of-way for the various streets (major streets, collector streets, minor streets and alleys) are indicated below. Widths shall be not less than as follows:

    Street Types Right-of-Way
    Major street 120 feet
    Collector street  60 feet
    Minor street and cul-de-sac  50 feet
    Alleys  20 feet
    Marginal access (included in R/W of arterial)

     

    (b)

    In cases where topography or other physical conditions make a street of the required minimum width impracticable, the planning commission may modify the above requirements. Through proposed neighborhood or local business areas, the road widths shall be increased ten (10) feet of each side to provide for movement of vehicles into and out of necessary off-street parking areas without interferences to traffic.

    (c)

    Additional width on existing roads. Subdivisions that adjoin existing roads shall dedicate additional right-of-way to meet the above minimum road width requirements.

    (1)

    The entire right-of-way shall be provided where any part of the subdivision is on both sides of the existing road.

    (2)

    When the subdivision is located on only one side of an existing road, one-half (½) of the required right-of-way, measured from the center line of the existing roadway, shall be provided.

    (2.7)

    Minimum roadway widths. The minimum pavement widths for the various classifications of streets shall be as follows:

    Street Types Pavement Width (measured from pavement edge to pavement edge)
    Major street as required
    Collector street as required
    Minor street and cul-de-sac 26 feet
    Alley 20 feet

     

    (2.8)

    Street grades.

    (a)

    Street grades shall not exceed the following unless otherwise recommended and approved by the county road superintendent.

    Street Type Grade
    Major street 4%
    Collector street 6%
    Minor street and cul-de-sac 7%
    Marginal access street 7%

     

    (b)

    Grades approaching intersections shall not exceed five (5) per cent for a distance of not less than one hundred (100) feet from the center line of said intersection.

    (c)

    Minimum grades of all roadways shall not be less than five-tenths (0.5) per cent.

    (d)

    Surface cross-drainage shall not be permitted on any street.

    (e)

    Vertical curves shall be constructed so as to afford a minimum sight distance being measured from the driver's eyes (4 ½ feet above pavement surface) to an object four (4) inches high on the pavement surface.

    (2.9)

    Alignment and visibility.

    (a)

    Minimum radii of horizontal curves shall be not less than one hundred (100) feet.

    (b)

    There shall be a tangent for [of] one hundred (100) feet provided between all reverse curves.

    (c)

    Angular breaks in right-of-way alignment of more than two (2) degrees are not permitted.

    (d)

    Visibility. Clear horizontal visibility, measured along the center line, shall be provided for at least six hundred (600) feet on freeways and major streets; three hundred (300) feet on collector streets; and at least two hundred (200) feet on minor access and rear service streets.

    (e)

    Where an existing road or other right-of-way falls within a proposed subdivision tract and the subdivider proposes to abandon this right-of-way, the planning commission shall review this proposal in light of its effect on neighboring properties, and forward its recommendations to the governing body prior to its taking legal action on the matter. (See Article V, section 8)

    (f)

    Where there are roads and rights-of-way in existence and they are proposed to be retained, they must be designed so as to eliminate all bends, crooks and other undesirable hazardous conditions.

    (2.10)

    Intersections.

    (a)

    Submission of a grading plan showing existing conditions and a detailed design for intersections which are unusual or located on difficult terrain may be required by the planning commission.

    (b)

    Acute angles at street intersections are to be avoided; in no case will an angle of less than sixty (60) degrees be permitted.

    (c)

    Minimum radii of intersections.

    (1)

    Property lines at major street intersections shall be rounded with a radius of ten (10) feet. An increased radius shall be required when the angle of intersection is less than ninety (90) degrees.

    (2)

    Roadway and curb intersections shall be made concentric and shall be rounded by a radius of not less than twenty-five (25) feet.

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    Street Intersections Illustration

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    Sight Lines Illustration

    (d)

    Sight lines. Minor and collector streets shall have a clear sight triangle of seventy-five (75) feet (150 feet for major streets) from the point of intersection; this shall be indicated on all plans. No buildings or other obstructions between three (3) feet to fifteen (15) feet in height shall be permitted in this area.

    (2.11)

    Alleys.

    (a)

    Alleys may be required in commercial and industrial districts, except that the planning commission may waive this requirement where other definite and assured provision is made for service access, such as off-street loading, unloading and parking facilities consistent with zoning requirements.

    (b)

    Alleys are not permitted in residential districts, except when the planning commission determines special conditions warrant a secondary means of access.

    (2.12)

    Names.

    (a)

    No street name shall be used which will duplicate by spelling or sound or otherwise be confused with the name of existing streets. Street names are subject to the approval of the planning commission.

    (b)

    Subdivision names and apartment project names shall not duplicate or be confused with existing names and are subject to approval by the planning commission.