A. The minimum required right-of-way widths shall be as follows:
1. Major arterial streets and highways, as required by current city standards.
2. Collector streets as indicated by current city standards.
3. Local streets, as indicated by current city standards. In addition:
a. Cul-de-sac streets shall terminate in a circular right-of-way 45 feet in radius with an improved traffic turning circle 40 feet in radius. The city staff may approve an equally convenient form of space where extreme conditions justify.
b. Dead-end streets will not be approved except in location designated by the planning commission as necessary to future extension in development of adjacent lands. In any case, a dead-end street serving more than 4 lots, shall provide by easement a temporary turning circle with a 40-foot radius or other acceptable design to accomplish adequate access.
4. Frontage streets as indicated by current city standards.
5. Alleys:
a. Sixteen feet if single-family residential on both sides;
b. Thirty feet if abutting commercial, multiple-family residential or industrial districts.
B. Alley intersections and sharp changes in alignment shall be avoided, but where necessary corners shall be cut off 15 feet on each side to permit safe vehicular movement. Dead-end alleys are prohibited.
C. The vertical alignment of streets shall be as follows:
1. Street grade maximums shall be:
a. Arterial routes, as determined by the City Engineer.
b. Collector, 7%.
c. Local residential streets, 9%.
2. Concrete or asphalt streets with concrete gutters, 0.4% is desirable.
D. 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 city staff.
1. Vertical curves in streets shall be as follows:
a. Arterial routes, as determined by the city.
b. Collector and minor streets minimum length, 100 feet, except in cases approved by the city.
E. The horizontal alignment of streets shall be as follows:
1. Arterial routes, as determined by the city.
2. When tangent centerlines deflect from each other more than 10 degrees and less than 90 degrees, they shall be connected by a curve with a minimum centerline radius of 500 feet for collector streets or 100 feet for local streets.
3. Between reverse curves there shall be a tangent section of centerline not less than 100 feet long, unless the radius exceeds 600 feet on collector streets or 200 feet on local streets, in which cases no tangent is required.
4. Streets intersecting an arterial route shall do so at an angle which shall not vary from 90 degrees by more than 4r degrees; intersections of local streets shall not vary from 90 degrees by more than 15 degrees.
5. Street jogs with centerline offsets of less than 125 feet shall be avoided except under special circumstances.
6. Minor streets intersecting a collector street or arterial route shall have a tangent section of centerline at least 150 feet in length measured from the right-of-way line of the major street. No such tangent is required when the minor street curve has a centerline radius greater than 400 feet with the corner located on the major street right-of-way line. Where topographic conditions make necessary other treatment to secure the best overall design, these standards may be relaxed by the city staff.
7. Street intersections with more than 4 legs and "Y" type intersections where legs meet at acute angles shall be avoided.
8. At street intersections, property line corner shall be rounded by circular arc, said arc having a minimum tangent length of 12 feet.
F. Private streets shall be constructed to conform to current city standards.
(Prior Code, § 12-3-3) (Ord. 08-913, passed 3-11-2008)