§ 151.056 PRINCIPLES OF STREET DESIGN.
   (A)   The subdivider shall be guided by the following principles in laying out the street system within the subdivision.
   (B)   All parcels shall have adequate and safe vehicular and pedestrian access and street systems shall be designed to minimize through traffic movement. However, connections into and from adjacent areas may be required by the Plan Commission where it will not substantially increase through traffic. The design shall provide reasonable direct access to the primary circulation system and not conflict with the efficiency of bordering arterial routes.
   (C)   To function effectively and safely, the circulation system within a subdivision shall be designed with the least number of interruptions possible and further to discourage excessive speeds and minimize pedestrian-vehicular points of conflict. The streets shall be related to topography and shall minimize space devoted to streets and intersections.
   (D)   All dedicated rights-of-way shall conform to the following minimum widths:
      (1)   Arterial streets. 120 feet;
      (2)   Major collector streets. 100 feet;
      (3)   Minor collector streets. 70 feet;
      (4)   Local residential streets. 50 feet;
      (5)   Cul-de-sacs, residential. 50 feet (radius);
      (6)   Cul-de-sacs, all other subdivisions. 60 feet (radius);
      (7)   Crosswalks. 10 feet; and
      (8)   Utility easements. 20 feet.
   (E)   The following criteria in street design shall be observed in laying out streets in a new subdivision:
      (1)   Street jogs with center line offsets of less than 125 feet shall not be permitted (Illustration 1);
      (2)   All streets shall intersect at 90 degrees whenever possible for a minimum distance of 100 feet. However, in no instance shall they intersect at less than 80 degrees onto arterial or collector streets or less than 50 degrees onto local streets (Illustration 2);
      (3)   To ensure adequate sight distance, when the street center lines deflect more than 10 degrees, connections shall be made by horizontal curves. The minimum center line radius for local residential streets shall be 200 feet and for all other residential streets, 400 feet (Illustration 3);
      (4)   A tangent of at least 100 feet shall be introduced between reversed curves on local and collector streets (Illustration 4);
      (5)   Clear visibility, measured along the center line of the street, shall be provided for at least 600 feet on all arterial streets, 400 feet on collector streets and at least 200 feet on all local streets;
      (6)   The maximum vertical grade for arterial streets shall not exceed 7.5%, for collector streets 10% and for local streets 12%; provided, however, that within 200 feet of a street or railway intersection, the maximum grade permitted shall be 50% of the maximum grade specification;
      (7)   The maximum length for cul-de-sac streets shall be 800 feet measured along the center line from the intersection at origin through the center of the circle to the end of the right-of-way. Each cul-de-sac shall have a terminus of nearly circular shape with a minimum right-of-way diameter of 100 feet for residential use and 120 feet for industrial use, unless an equally safe and convenient form of space is approved by the Plan Commission (Illustration 5);
      (8)   Only one street or point of vehicle access shall be permitted from a subdivision onto a major collector street or an arterial street or road. Two or more streets or points of vehicle access onto a minor collector street may be permitted by the Plan Commission only if they are definitely needed to improve the safety and traffic circulation in the area;
      (9)   No street names may be used which will duplicate or be confused with names of existing streets. Streets which are logical extensions or continuations of existing streets shall bear the names of the existing streets;
      (10)   Rights-of-way for proposed streets shall be extended to the boundary lines of the proposed subdivision so that a connection can be made to adjacent properties, unless the extension is not feasible because of topography or other physical conditions or unless, in the opinion of the Plan Commission, the extension is not necessary or desirable for the advantageous development of adjacent tracts. No subdivision shall be designed so as to create or perpetuate the land-locking of adjacent undeveloped land;
      (11)   Temporary dead-ended streets shall be permitted only when a street is proposed and should logically be extended but is not yet constructed. An adequate easement for a turn-around shall be provided for all temporary dead-ended streets which extend 200 feet or more in length. The easement shall be automatically vacated to abutting property owners when the street is extended;
      (12)   In subdivisions that adjoin or include existing streets that do not conform to the minimum right-of-way dimensions as established by this chapter, the subdivider shall dedicate additional width along either one or both sides of the streets so as to bring them up to standards, provided the area to be used for widening is owned or under the control of the subdivider; and
      (13)   No driveway shall be located within 70 feet of the intersection of two street lines.
 
 
(Ord. 83-003, passed 4-12-1983)