10-5-3: STREETS:
   A.   General Standards:
      1.   Proposed streets shall conform to the state road and county highway plans as have been prepared, adopted and/or filed as prescribed by law, and to the city's comprehensive plan.
      2.   Streets shall be logically related to the topography to produce usable lots and reasonable grades.
      3.   Local streets shall be laid out to discourage their use by through traffic.
      4.   Where adjoining areas are not subdivided but may be subdivided, the arrangement of streets shall make provision for the projection of streets into adjoining areas, by carrying the new streets to the boundaries of the new subdivision at appropriate locations. The street arrangement shall not cause hardship to owners of adjoining land in platting their own land and providing convenient access to it.
      5.   Half or partial streets will not be permitted, except where reasonable subdivision of a tract is in conformance with other requirements and standards of this title and where satisfactory assurance for dedication of the remaining part of the street right of way can be secured. Wherever a tract to be subdivided adjoins an existing half or partial street, the part of the street within such tract shall be platted.
      6.   Dead end streets shall be prohibited, except as stubs to permit future street extension in adjoining tracts or when designed as cul-de-sac streets. Temporary turnarounds shall be provided.
      7.   Private streets shall be prohibited, unless approved by the city council as part of a planned unit development subdivision or overlay district.
      8.   Subdivisions abutting arterial roads, as defined in the comprehensive plan must include a buffer strip averaging seventy five feet (75') wide meeting requirements in section 11-6-20 .
      9.   All landscaped medians and cul-de-sac islands must be landscaped. A landscape plan must be submitted to the city for review and approval.
      10.   A uniform landscape design, utilizing natural landscape plantings and materials, must be installed around the perimeter of all ponds, infiltration basins, and similar drainage features.
      11.   A uniform mailbox design must be approved as part of the preliminary plat review and approval process.
   B.   Minor Arterials And Collector Streets:
      1.   Access of minor streets onto state and county state aid highways, or to streets designated as collectors or minor arterials, shall be prohibited at intervals of less than six hundred sixty feet (660').
      2.   Where a proposed plat is adjacent to a minor arterial street, there shall be no direct vehicular access from individual lots to such streets and roads. In platting small tracts of land fronting on minor arterials where there is no other alternative, a temporary entrance may be granted; as neighboring land is subdivided and more preferable access arrangements become possible, such temporary access permits shall become void.
      3.   Where a subdivision abuts or contains an existing or planned collector or minor arterial street or a railroad right of way, a street approximately parallel to and on each side of such thoroughfare and right of way may be required for adequate protection of residential properties and separation of through and local traffic. Such service streets shall be located at a distance from the major thoroughfare or railroad right of way suitable for the appropriate use of the intervening land, as for park purposes in residential districts or for commercial and industrial purposes in appropriate districts. Such distances shall also be determined with due regard for the requirements of approach grade and future grade preparations. (1971 Code § 23-31)
   C.   Street Widths:
      1.   Minimum right of way widths and pavement widths, face to face of curb, for each type of public street or road shall be as follows:
Type Of Street
Right Of Way Width
Roadway Width
Type Of Street
Right Of Way Width
Roadway Width
Minor arterial street
120 - 160 feet
As determined by traffic needs
Collector street/
80 feet
48 feet
Commercial/industrial collector service street
80 - 120 feet
52 feet
Local street
60 feet
32 feet
Local street - East Ravine neighborhood 1 north
60 feet
28 feet
Cul-de-sac turnaround radius
60 feet
47 feet
Cul-de-sac/rural other than a collector roadway
60 feet
28 feet
      2.   Where a subdivision abuts or contains an existing street of inadequate right of way width, additional right of way width shall be provided.
      3.   Additional right of way and roadway widths may be required to promote public safety and convenience when special conditions require, or to provide parking space in areas of intensive use.
      4.   Extensions of existing streets with lesser right of way widths than prescribed above may be permitted only as a part of a "planned unit development" as defined in the zoning ordinance.
   D.   Cul-De-Sac Streets:
      1.   Cul-de-sac streets, permanently designed as such, shall not exceed six hundred feet (600') in length, except where, by reason of unfavorable land form or the irregular shape of the land, a normal pattern cannot be established, or that land would be underutilized.
      2.   Unless future extension is clearly impracticable or undesirable, the turnaround right of way shall be placed adjacent to a subdivision property line, and a right of way of the same width as needed for the type of street shall be carried to such property line in such a way as to permit future extension of the street into the adjoining tract. At such time as such a street is extended, the acreage covered by the turnaround outside the boundaries of the extended street shall revert in ownership to the property owner fronting on the temporary turnaround.
   E.   Street Grades:
      1.   Streets shall be graded in accordance with the plan approved by the engineer. The grading shall include the entire width of the right of way and shall provide a boulevard section in addition to the minimum pavement width.
      2.   Centerline gradients shall be at least five-tenths percent (0.5%) and shall not exceed the following:
Minor arterials and collector streets
5 percent
Local streets
8 percent
      3.   Different connecting street gradients shall be connected with vertical curves. Minimum length, in feet, of these curves shall be twenty (20) times the algebraic difference in the percent of grade of the two (2) adjacent slopes.
   F.   Pavement: All streets and alleys shall be improved with concrete or bituminous surface and with concrete curb and gutter, except as may otherwise be approved by the governing body for rural areas identified in subsection F2 of this section.
      1.   Urban Areas:
         a.   The design of street pavement for all streets covered by this title shall be in accordance with the state transportation department "Road Design Manual No. 5-291" for flexible pavements. The design thickness of the surfacing elements shall be in accordance with the flexible pavement design standard for road classifications as follows:
Pavement Design: Axle Load
Minor arterial, collector and commercial service streets
As determined by projected traffic needs
Local streets
7 ton minimum
         b.   To determine subgrade soil classifications, soil samples shall be collected and analyzed by a reputable testing laboratory. The soil analysis shall be submitted to the engineer with the pavement plans. Soil samples shall be taken along the centerline of the proposed road, at intervals not exceeding three hundred feet (300').
         c.   Concrete curbs and gutters shall be constructed on both sides of streets. The construction shall be in accordance with "Standard Specification For Highway Construction", state highway design specification no. 2531. Concrete curb and gutter cross sections shall be either design no. B618 or design D.
      2.   Rural Areas:
         a.   Unless otherwise approved by the council, new streets in rural areas shall be improved to urban standards. The council may approve streets to be surfaced with gravel if there will be three (3) or fewer lots abutting the proposed street.
         b.   Streets which will have only a gravel surface shall be so designed that the base and subbase requirements of state transportation department "Road Design Manual No. 5-291" for flexible pavement are met. At least the top six inches (6") of the street surface shall be of class 5 gravel or a material approved by the engineer.
   G.   Intersections And Street Jogs:
      1.   The angle formed by intersecting streets shall not be less than sixty degrees (60°), with ninety degree (90°) intersections preferred.
      2.   Intersections of more than four (4) corners shall be prohibited.
      3.   Roadways of street intersections shall be rounded by a radius of not less than fifteen feet (15'). Roadways of alley-street intersections shall be rounded by a radius of not less than six feet (6'). Corners at the entrance to the turnaround portion of cul-de-sacs shall be rounded by a radius of not less than fifteen feet (15').
      4.   Street jogs with centerline offsets of less than one hundred fifty feet (150') shall not be allowed.
      5.   When connecting street lines deflect from each other at any one point by more than ten degrees (10°), they shall be connected by a curve with a radius of not less than two hundred seventy five feet (275') unless waived by the city council. (1971 Code § 23-31)
   H.   Boulevard And Yard Improvements:
      1.   In urban and rural areas, all boulevards and yards must have a minimum of four inches (4") of organic topsoil or black dirt placed on them and then be sodded as specified in this title.
      2.   Driveways shall be constructed from the curb to minimum structural setback and the width of the proposed driveway in all the R-3 and R-4 zoning districts. The driveway shall be constructed of four inch (4") thick asphalt or air intrained concrete three thousand (3,000) psi, brick pavers or better. This provision is not required in rural zoning districts.
   I.   Street Trees: See section 11-6-20 .
   J.   Sodding Of Residential And Commercial Lots:
      1.   The entire lot area, except for areas proposed for landscape beds and below the high water elevation for storm water basins for all residential and commercial lots in new developing urban areas must be sodded.
      2.   All residential and commercial lots in rural areas shall be sodded from the street curb to the minimum front yard setback line of the zoning district therein located.
   K.   Street Names And Signs:
      1.   Names of new streets shall not duplicate existing or platted street names unless a new street is a continuation of, or in alignment with, the existing or platted street, in which event, it shall bear the name of the existing or platted street. Street names shall conform to the county uniform street naming and property numbering system1.
      2.   All street signs shall be provided and installed by the city at the expense of the subdivider. (1971 Code § 23-31; amd. 2000 Code; Ord. 796, 6-21-2006; Ord. 1035, 11-18-2020)