A. Location And Arrangement:
1. Official Street And Highway Plan: Whenever a tract to be subdivided embraces part of a street designated in an official street and highway plan of the city, such street shall be platted in conformance therewith.
2. Layout: Street layout shall provide for the continuation of such streets as the commission may designate.
3. Extensions: Certain proposed streets, as designated by the commission, shall be extended to the tract boundary to provide future connection with adjoining unplatted lands. Such extensions shall generally not be farther apart than the maximum permitted length of a block, as hereinafter provided.
4. Local Streets: Local streets shall be so arranged as to discourage their use by traffic originating outside the immediate neighborhood.
5. Marginal Access Streets: Lots intended for single-family residential use shall not normally front or have access from arterial streets. Where a proposed subdivision abuts an existing or proposed arterial street, the commission may require marginal access streets or reverse property frontage with nonaccess easements abutting the arterial streets, or such other treatment as may be justified for protection of residential properties from the nuisance and hazard of high volume traffic, and for protection of the traffic function of the arterial street.
6. Limited Access Highway: Where a residential subdivision abuts the right of way of a railroad, a limited access highway or a commercial or industrial land use, the commission may require location of a street approximately parallel to such right of way or use at a distance being determined with due regard for approach grades, drainages, bridges and future grade separation.
7. Topography: Streets shall be so arranged in relation to topography as to produce desirable lots of maximum utility and streets of reasonable gradient, and to facilitate adequate surface drainage.
8. Alleys: Where alleys are permitted, their alignment and arrangement shall be such as to minimize backtracking and single- tier service by trash collection forces and to avoid the facing of residences directly into alley openings.
9. Half Streets: Half streets shall be prohibited. In the event that any subdivision is constructed and a street borders undeveloped real property, the owner of the subdivision or its successors in interest shall be entitled to receive reimbursement for one-half (1/2) of all costs of construction of the street in the event that the undeveloped real property is developed within ten (10) years of the date of completion of the construction of the street.
10. Dead-End Streets: Dead-end streets shall be prohibited unless a modification is granted by the commission in locations designated by the commission as necessary for future street connection to adjacent unplatted lands.
11. Separation Of Grades; Intersections: Whenever any street or highway is proposed requiring a separation of grades or requiring any special form of intersection design at its intersection with any street, highway or railway, the subdivision shall be so designed to conform to any plan adopted by the city for the intersection design and all lots within the subdivision shall, when necessary, be provided with suitable access from another public way. Any street or highway intersecting with another street or highway shall intersect it at an angle as nearly a right angle as shall be practicable. (Prior Code § 18A-12)
B. Design:
1. Required Right Of Way And Street Widths:
a. Primary Or Arterial: Shall have a right-of-way width of one hundred feet (100') or more and an improved section of seventy seven feet (77'), and may contain a center dividing strip.
b. Secondary Roads: Shall have a right-of-way width of eighty feet (80') or more, and an improved section of sixty five feet (65').
c. Collector And Local Streets: Shall have a right-of-way width of sixty feet (60') or more, and an improved section of fifty feet (50').
d. Limited Access Street: Shall have a right-of-way width of fifty feet (50') or more, and an improved section of not less than thirty six feet (36').
e. Cul-De-Sac Street: Shall have a right-of-way width of fifty feet (50') or more, and an improved section of not less than thirty six feet (36'). Total center line length is not to exceed four hundred feet (400'). Such street shall terminate in a circular right of way not less than fifty feet (50') in radius with an improved turning circle at least forty five feet (45') in radius.
f. Alleys: Where permitted or required, twenty feet (20') abutting commercial or industrial property.
(1) Alleys in residential sections shall be prohibited.
(2) Alley intersections and sharp changes in alignment shall be avoided, but where necessary, corners shall be cut off ten feet (10') on each side to permit safe vehicular movement.
(3) Dead-end alleys shall be prohibited.
(4) Half alleys shall be prohibited.
g. Dead-End Streets: Where permitted, a dead-end street serving more than four (4) lots shall provide, by easements, temporary turning circle with a fifty foot (50') radius or other approved and acceptable design to accomplish the same purpose.
h. Lesser Developed Street Rights Of Way: Lesser developed street rights of way and sections may be permitted when it can be clearly established that no on-street parking is required or desired or where related to planned unit development approaches. Increased widths may be required where streets are to serve commercial property or where public traffic conditions warrant such. In both cases, final sections will be recommended by the city engineer and established by the city council and planning commission.
2. Grades:
a. Maximum Grades:
(1) Arterial Streets: As determined by the city engineer.
(2) Collector Streets: Eight percent (8%).
(3) Local Streets: Ten percent (10%).
b. Minimum Grades: Asphalt streets with concrete gutters:
(1) Desirable: 0.50.
(2) Minimum: 0.30.
c. Exceptions: Where rigid adherence to these standards causes unreasonable or unwarranted hardship in design or cost without commensurate public benefit, exceptions may be made by the commission.
3. Vertical Curves:
a. Arterial And Secondary Streets: All changes in grade should be connected by a vertical curve of minimum length equal to twenty (20) times the algebraic difference in the rates of grade or a length of one hundred feet (100'), whichever is larger.
b. Collector And Local Streets: The length of curve for these streets should be ten (10) times the algebraic difference in the rates of grade or a length of one hundred feet (100') whichever is larger.
c. Reverse Or Compound Curves: Reverse or compound curves shall be separated by tangents of not less than one hundred feet (100') on primary, secondary and collector streets.
4. Horizontal Alignment:
a. Arterial Streets: For arterial streets, as determined by the city engineer.
b. Tangent Center Lines: When tangent center lines deflect from each other by more than ten degrees (10°) and less than ninety degrees (90°), they shall be connected by a curve having a minimum center line radius of two hundred feet (200') for collector streets or one hundred fifty feet (150') for local streets.
c. Reverse Curves: Between reverse curves there shall be a tangent section of center line not less than one hundred feet (100') long.
d. Intersections With Arterial Streets: Streets intersecting an arterial street shall do so at a ninety degree (90°) angle. Two (2) collector streets, two (2) local streets or a collector and a local street shall typically intersect at ninety degree (90°) angles, but in no case at less than seventy five degree (75°) angles.
e. Street Jogs: Street jogs shall be avoided except where justified by unusual existing conditions and approved by the city engineer.
f. Local Streets Intersecting Collector Or Arterial Street: Local streets intersecting a collector street or arterial street shall have a tangent section of center line at least one hundred fifty feet (150') in length measured from the right-of-way line of the more major street; except, that no such tangent shall be required when the local street curve has a center line radius greater than four hundred feet (400') measured from a center line located on the more major street right-of-way line.
g. Intersections: Street intersections with more than four (4) legs, and Y-type intersections with legs meeting at acute angles, shall be prohibited.
5. Asphalt Thickness: Minimum asphalt thickness of all streets shall be two and one-half inches (21/2").
6. Slope And Fill Requirements:
a. Maximum Slope: No existing slope or proposed cut slope shall be steeper than one and one-half horizontal to one vertical (11/2:1) and no fill slope, existing or proposed, shall be steeper than two horizontal to one vertical (2:1), unless recommended by a competent soils engineer acceptable to the City. Slope areas are not to be included in usable lot areas.
b. Slope Easement: Where a cut or fill slope is outside the normal right of way of the street, a slope easement shall be provided of sufficient width to permit proper maintenance of the slopes by the city, or the dedicated right-of-way width shall be widened to include such slopes.
c. Retaining Walls: Retaining walls may be required whenever topographic conditions warrant or where necessary to retain fill or cut slopes within the rights of way or slope easement.
d. Fills: All fills to be used for building sites shall be compacted to not less than ninety percent (90%) in accordance with AASHO modified specification T149-57.
C. Naming: At the preliminary plat stage, the subdivider shall propose names for all streets, which names shall be subject to approval by the commission. (Prior Code § 18A-14)