(a)   Arrangement and extension.
      (1)   The arrangement of streets in new subdivisions shall conform to the major street plan and shall make provisions for the continuation of existing streets in adjoining areas or their proper projection where adjoining land is not subdivided.
      (2)   The arrangement of all streets and alleys shall be such as not to cause a hardship to owners of adjoining property when they plat their own land and seek to provide for convenient access to it.
   (b)   Circulation plan. In general, streets within subdivisions shall be designed to incorporate and tie
into existing or proposed pedestrian pathways and roadways, and to take into account design restrictions on abutting parcels caused by the surrounding topography, parcel lines, or other features. Other criteria in the street circulation plan shall include the following:
      (1)   Provisions should be made for a collector street every quarter mile, and there should be a street connecting adjacent subdivisions at intervals not less than a quarter mile where environmental constraints and land use considerations permit. In cases where the connectivity of collector streets are not feasible because of environmental constraints and land use considerations, provisions shall instead be made for a walkway or bike trail to connect the adjacent subdivisions through the shortest and most reasonable method possible. The developer may need to negotiate with adjacent landowners or government entities to determine if the connection is feasible.
      (2)   Streets should be designed to convey residents conveniently throughout the neighborhood, and to the parks, schools, and shopping areas of the neighborhood and to adjacent neighborhoods. When a subdivision is designed or constructed in conjunction with another use (such as retail, office, apartments, park, or school) of a neighborhood scale, the local and/or collector road system should be designed to provide roadway connections between the various uses.
   (c)   Arterial streets. In order to maintain the traffic carrying capacity of the arterial streets by limiting access to it from individual lots, and in order to protect the residents of property adjacent to arterial streets from the high traffic volumes associated with the street, property along the arterials shall be subdivided in the manner set forth below.
      (1)   Double frontage lots. Double frontage lots shall only be used where necessary to provide separation of residential development from through traffic or to overcome specific disadvantages of topography and orientation. Where double frontage lots are used for residential development, additional lot depth or width consistent with the zoning ordinance for rear yard setback shall be required to provide for an extra setback to offset the impact of high traffic volume. All required public improvements within the adjoining local/collector street right-of-way or easement areas, whether proposed or existing, shall be complete and accepted by the city engineer prior to approval of the plat. The city engineer may determine that immediate completion of the public improvements is not feasible, and in lieu of completion of the required public improvements prior to plat approval the developer shall be required to meet one or more of the following:
         A.   Financially securitize all uncompleted public improvements, which are the responsibility of the developer seeking plat approval.
         B.   Provide other assurances as approved by the city engineer.
      (2)   Tracts onto arterial streets. In order to avoid private access from individual lots onto arterial streets, lots should be arranged on blocks so that their side or rear yards are adjacent to the arterial street. Lots adjacent to an arterial street shall have an additional width to provide for an extra setback to offset the impact of high traffic volume. This design will be accepted only for a limited distance due to the number of streets that would intersect with the arterial.
      (3)   Access roads. Access roads may be used as the city grows into the areas in the county where they have been required. Under some circumstances, they would also be appropriate for commercial and industrial development. Access roads shall be constructed to city standards with a right-of- way width of 50'.
      (4)   Rear access roads. Rear access roads are recommended for commercial developments. In this way, the access can serve two tiers of lots and alleviate the dangerous turning movements onto and off of arterial streets.
      (5)   Nonresidential land uses. Nonresidential land uses and higher density residential land uses including multiple-family units and townhouses are particularly suitable for the intersection of two arterial streets. Any development of this type should have limited access to the arterial street.
      (6)   Lots adjacent to railroad right-of-way. Lots for residential development adjacent to functioning railroad rights-of-way shall provide extra lot depth or width consistent with the zoning ordinance for rear yard setback to provide for an extra setback to offset the impact of the railroad traffic.
   (d)   Collector street development.
      (1)   Collectors shall be used to collect traffic from other local roads and collectors to arterial roadways. They should generally run three miles in length.
      (2)   Based upon increased speeds and volumes, lot sizes and land uses may be increased along collectors to be consistent with the proposed zoning and transitions.
      (3)   Collectors shall be developed along or between property lines so that both landowners can share in the cost as well as having access to the collector.
      (4)   In agricultural and transitional areas, collector streets shall be identified and located through the Engineering Design Standards.
   (e)   Right-of-way widths. The developer shall be required to dedicate street right-of-way widths according to the major street plan and not less than as follows:
      Street Type Right-of-Way (in feet)
      Access roads: 50
      Alleys: 20
      Arterials: 100
      Collectors: 66-80
      Cul-de-sacs (55 radius for turnarounds and eyebrows): 50
      Expressway/principals: 100
      Locals: 60*
      Rural subdivisions: 66
      * 66' in multifamily, commercial, and industrial zoned areas
   (f)   Cul-de-sacs. Cul-de-sacs will be allowed where they are necessary for the reasonable development of a subdivision.
      (1)   The maximum length of a cul- de-sac shall be 500' measured along the centerline, between the radius point of the turnaround and the right-of-way line of the abutting street. The maximum length of a cul-de-sac may be extended where no other practical alternative is available for the reasonable development of a subdivision.
      (2)   Temporary turnarounds may also be required by the city engineer on dead-end streets that will eventually be continued.
      (3)   Emergency access may be required by the fire chief on cul-de-sac streets to allow for emergency service response.
   (g)   Private streets or roads. Private streets may be allowed when serving a limited number of parcels if right-of-way constraints exist and when all maintenance responsibilities are detailed within the easement. The following standards must be met:
      (1)   A private street must have a minimum of 28' of paved drivable surface and shall meet Engineering Design Standards for a private street.
      (2)   A private street easement may share the public utility easement required within § 157.117.
      (3)   All private streets must be platted as a private street easement that shall be recorded with the county register of deeds. The private street easement shall not be included as part of any required lot area or setback for purposes of the zoning ordinance.
      (4)   Any nonresidential development that proposes private streets shall include sidewalks on both sides of the street, curb and gutter, streetlights, and driveways all to city Engineering Design Standards.
      (5)   Any nonresidential development that proposes private streets and that is required to do a traffic study shall include any additional design recommendations into the developer’s engineering plan.
      (6)   An alternative pedestrian plan may be proposed for approval by the planning director and city engineer to allow alternative sidewalk connections that still provide the same pedestrian connections to proposed buildings in the development.
      (7)   The plat shall have the owner’s certificate regarding the private street easement’s private maintenance of facilities and shall have a maintenance agreement as required within § 157.116.
(1992 Code, App. A, § 15A.07.040) (Ord. 81-08, passed 7-7-2008; Ord. 8-13, passed 3-5-2013; Ord. 87-18, passed 10-2-2018)