§ 1. Street plan.

1.1. General. The arrangement, character, extent, location and grade of all streets shall be laid out according to good land planning principals and shall be integrated with all existing and planned streets. Land abutting a proposed subdivision shall not be land-locked by the proposed subdivision.

The proposed street system shall 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 multiple-street intersections shall not be permitted. The street pattern shall be in conformity with a plan for the most advantageous development of the entire community.

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 turnaround, as defined in design standards for street cul-de-sac, shall be provided. Local streets shall be so laid out that their use by through traffic in the subdivision will be discouraged.

Subdivisions which abut or have included within the proposed area to be subdivided any freeway or arterial street shall provide for the adequate protection of properties, and afford separation of through and local traffic.

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

1.2. Control of access. Because of the unique qualities of a planned unit development approved under the provisions of Article XII of the Zoning Ordinance, the city may approve, as part of the PUD and subdivision approval processes, the use of security points for the control of access on public streets. Security points shall be privately owned and maintained. Prior to installation of a security point, the owner shall post a maintenance bond or other security approved by the city, in an amount determined by the city to be sufficient to insure the proper maintenance of the security point.

As a minimum, the city shall consider the following, as part of the approval process for the installation of security points for the control of access on public streets:

a.

The number and location of security points;

b.

Traffic circulation within and outside of the PUD;

c.

Effect upon adjacent and surrounding properties; and

d.

The provision of municipal and other public services.

When a previously approved PUD requests permission to dedicate private streets and install or maintain a security point on said streets, the city may require public dedication of all private streets which are connected to the private streets proposed for dedication.

The use of security points for the control of access on public streets shall not be permitted outside of a PUD approved under the provisions of Article XII of the Zoning Ordinance. (Ord. No. 97-1556, § 2, 5-19-97)

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

1.4. Land subject to flooding. Land subject to flooding, or land deemed to be topographically unsuitable for urban usage, shall not be platted for residential occupancy, nor for any other uses which may increase danger to health, life or property, aggravate erosion or increase flood hazard.

1.5. 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.

1.6. Cul-de-sacs. Streets designed to have one end permanently closed shall be provided at the closed end with a turnaround having a minimum right-of-way radius of fifty (50) feet, and a minimum roadway radius of forty (40) feet.

1.7. Street intersections. Street intersections with centerline offsets of less than one hundred twenty-five (125) feet shall not be permitted, unless approved by the planning commission.

1.8. Minimum street right-of-way widths. The planning commission shall determine the classification of all city streets. The widths of rights-of-way for the various streets are indicated below. Widths shall be not less than as follows:

Street Type	Minimum Right-of-Way Width (feet)
Local street	50
Collector street	50
Alley	20
Cul-de-sac (radius)	50

 

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

(a)

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

(b)

When the subdivision is located on only one side of an existing road, one-half of the required right-of-way, measured from the centerline of the existing roadway, shall be provided. The entire roadway width shall be paved, unless the planning commission gives written approval to the contrary.

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

Street Type	Minimum Pavement Width (feet)
Local street	22
Residential collector street	24
Commercial collector street	28
Alley	18
Cul-de-sac (radius)	40

 

1.10. Street grades.

(a)

Grades of all roads shall comply with accepted engineering practice. Road grades shall not exceed fifteen (15) percent or be less than one (1.0) percent. The planning commission may permit some variation from these grade requirements if such variation would not adversely affect the safety and general welfare of the public.

(b)

Grades approaching intersections shall not exceed three (3) percent equivalent rate for a distance of not less than fifty (50) feet from the centerline of said intersection.

(c)

Roads shall be graded to a minimum line of four (4) feet back of the curbline with a slope of one-half inch per foot.

(d)

Surface cross-drainage shall not be encouraged.

(e)

All roads shall be crowned in the center and have a one-fourth-inch per foot slope.

1.11. Alignment and visibility.

(a)

Minimum radii of horizontal curves shall be not less than two hundred fifty (250) feet.

(b)

There shall be a tangent for 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)

Clear horizontal visibility, measured along the centerline, shall be provided for at least two hundred fifty (250) feet in each direction.

(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 city council.

(f)

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

1.12. Intersections.

(a)

Road alignment shall be designed to eliminate sharp curves and street jogs. Roadway intersections which offset less than one hundred fifty (150) feet between centerlines shall be approved by the appropriate reviewing authority and the planning and zoning commission.

(b)

Roads shall intersect as nearly at right angles as possible and in no case at an angle of less than seventy-five (75) degrees.

(c)

The minimum curb radius at all intersections shall be at least twenty-five (25) feet; except where a residential alley intersects a public street, in which case the minimum curb radius shall be at least twenty (20) feet. (Ord. No. 00-1779, 10-16-00)

(d)

Local and collector streets shall have a clear sight triangle of seventy-five (75) feet from the point of intersection.

1.13. Alleys.

(a)

Alleys may be required in commercial and industrial districts, to facilitate access [parking], loading and service points.

(b)

Alleys are not permitted in residential districts, except when the planning commission determines special conditions warrant a secondary means of access, or when approved as part of a PUD, planned unit development. (Ord. No. 00-1779, 10-16-00)

1.14. 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 and building official.

(b)

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

1.15. Design speeds. [Design speeds shall be as follows:]

[1.] Local street, thirty (30) miles per hour.

[2.] Collector street, thirty-five (35) miles per hour.

The minimum radius of horizontal curves, and minimum length of vertical curves, shall be based on design speed and sight distance.

A variance on the minimum design speeds listed above must be approved by the planning commission. The minimum design speed that may be used is twenty-five (25) miles per hour. (Ord. No. 89-857, § 1, 1-13-90; Ord. No. 00-1783, § 5, 11-6-00)

1.16. Base material. A minimum of six (6) inches of compacted graded aggregate or approved equivalent shall be required on all roadbeds. Additional depth of base material may be required because of anticipated traffic. Eight (8) inches of compacted graded aggregate shall be required for commercial collector streets.

A minimum ninety-five (95) percent compaction for base material is required in accordance with ASTM D698 (standard proctor density). The planning commission may require compaction test results, performed by a licensed testing laboratory, prior to release of the performance bond.

1.17. Pavement. The minimum pavement thickness for the various classifications of city streets shall be as follows:

	Minimum Pavement Thickness (Inches)
Street Type	Binder	Seal
Local street	One	One
Residential collector street	One*	One
Commercial collector street	Two	One
Alley	One	One
Cul-de-sac (radius)	One	One

 

* The planning commission may require two (2) inches of binder.

If, in the opinion of the building official, the proposed street may fail or cause maintenance problems in the future, or in the case of actual street failure during construction, then a report by a geotechnical engineer shall be prepared and submitted to the building official for approval prior to the proposed street being constructed or completed. Such report shall determine the minimum base and pavement thickness required for a properly constructed street, as well as proof-rolling requirements for subgrade and removal of unsuitable material.

(Ord. No. 97-1556, § 2, 5-19-97)