§ 152.27  ROADS, HIGHWAYS, STREETS AND ALLEYS.
   (A)   The arrangement of highways shall conform as nearly as possible to the city’s Comprehensive Plan. Except for cul-de-sacs, roads and streets normally shall connect with roads and streets already dedicated in adjoining or adjacent subdivisions, or provide for future connections to adjoining unsubdivided tracts, or shall be a reasonable projection of roads in the nearest subdivided tracts. The arrangement of highways shall be considered in its relation to the reasonable circulation of traffic, to topographic conditions, to run-off or storm water, to public convenience and safety and in its appropriate relation to the proposed use of the area to be served.
   (B)   Local roads and streets should be so planned as to discourage their use by non-local traffic. Dead-end streets and roads shall be prohibited, but cul-de-sacs will be permitted where topography or other conditions justify their use. Cul-de-sacs shall normally not be longer than 500 feet, including a terminal turn-around which shall be provided at the closed end, with an outside curb radius of at least 50 feet and a right-of-way radius of not less than 60 feet.
   (C)   Where the plat to be submitted includes only part of the tract owned or intended for development by the subdivider, a tentative plan of a proposed future street and road system for the unsubdivided portion shall be prepared and submitted by the subdivider.
   (D)   When a tract is subdivided into larger than normal building lots or parcels, the lots or parcels shall be so arranged as to permit the logical location and openings of future roads and appropriate resubdivision, with provision for adequate utility connections for the resubdivision.
   (E)   Under normal conditions, roads shall be laid out as to intersect as nearly as possible at right angles, except where topography or other conditions justify variations. Under normal conditions, the minimum angle of intersection of roads shall be 70 degrees. Road intersection jogs with an offset of less than 125 feet shall be avoided.
   (F)   Wherever the proposed subdivision contains or is adjacent to the right-of-way of a highway, provision shall be made for a marginal access street or road approximately parallel and adjacent to the boundary of the right-of-way, or for a road at a distance suitable for the appropriate use of land between the road and right-of-way. The distance shall be determined with due consideration for the minimum distance required for approach connections to future grade separations or for lot depths.
   (G)   Alleys shall be provided in commercial and industrial districts; except that, this requirement may be waived where other definite and assured provision is made for service access, such as on-site loading, unloading and parking consistent with and adequate for the uses proposed. Except where justified by special conditions, such as the continuation of an existing alley in the same block, alleys will not be approved in residential districts. Alleys, where provided, shall not be less than 20 feet wide. Dead-end alleys shall be avoided wherever possible, but if unavoidable, the dead-end alleys may be approved if adequate turn-around facilities are provided at the closed end.
   (H)   Dedication of half streets or roads will not be approved, except where it is essential to the reasonable development of the subdivision and in conformity with the other requirements of these regulations, where it is found that it will be practical to require the dedication of the other half when the adjoining property is subdivided, or where it becomes necessary to acquire the remaining half by condemnation so that it may be improved in the public interest.
   (I)   (1)   For all public ways hereafter dedicated and accepted, the minimum right-of-way widths for streets and thoroughfares shall be as shown in the city’s Comprehensive Plan, and where not shown therein, the minimum right-of-way width for streets, roads, highways, alleys or pedestrian ways included in any subdivision shall not be less than the minimum dimensions for each classification as follows:
 
Alleys
20 feet
Collector streets
60 feet
Marginal service access roads
50 feet
Minor streets
60 feet
Pedestrian ways
10 feet
Thoroughfares
80 feet
 
      (2)   Where the existing or anticipated traffic on thoroughfares warrants greater widths of right-of-way, these shall be required.
   (J)   (1)   The grades in all streets, thoroughfares and alleys in any subdivision shall not be greater than the maximum grades for each classification as follows:
 
Alleys
8%
Collector streets
8%
Minor streets
8%
Thoroughfares
5%
 
      (2)   In addition, there shall be a minimum grade on all streets of not less than 0.005%.
   (K)   (1)   The horizontal and vertical alignment standards on all streets and thoroughfares shall be as follows.
         (a)   Horizontal, radii of centerline. There shall be a tangent between all reversed curves of a length in relation to the radii of the curves so as to provide for a smooth flow of traffic:
 
Collector streets
300 feet
Minor streets
100 feet
Thoroughfares
500 feet
 
         (b)   Vertical. All changes in street grades shall be connected by vertical parabolic curves in such length as follows:
 
Collector streets or minor streets
50-foot minimum
Thoroughfares
150-foot minimum
 
   (L)   All proposed streets or roads shall be offered for dedication as public rights-of-way. No private streets or roads shall be permitted.
(Prior Code, § 12.10)