(A) The road and street design of the subdivision shall provide direct access for lots and parcels of land within the subdivision and shall provide for continuity of arterial or collector roads and streets. The Plan Commission shall require the extension of certain roads or streets to the exterior boundary of the subdivision and shall require the subdivider to provide a partial right-of-way along an exterior boundary line to correspond to an existing public right-of-way on adjoining lands, or for the purpose of extending arterial or collector roads. Roads not immediately extended shall terminate in a legal cul-de-sac which may eventually be vacated.
(B) If the subdivision has 50 or more residential units, there shall be two separate entrances onto two separate roads. If the subdivision only fronts a single road, the subdivision shall have two entrances onto the road provided there is appropriate distance between entrances and other roadways and intersections. If there is not appropriate distance between entrances and other roadways and intersections, then a single entrance with a median divider is allowed. Each lane of the single entrance with a median divider shall be at least 16 feet if roll curbs are used or 18 feet if barrier curbs are used. The median shall be 12 feet in width to accommodate a separate left-turn lane if necessary. The median divider shall extend from the entrance of the intersection to the first crossroad or first intersection within the subdivision.
(C) The minimum width or rights-of-way shall be in accordance with the zoning ordinance (Chapter 156) and/or Thoroughfare Plan. The minimum width for utility easements shall be ten feet (five feet each side of the centerline of the easement). A dead-end street or cul-de-sac, if permitted by the Commission, shall terminate in a circular right-of-way providing for a minimum outside diameter of 100 feet. The standard design requirements for roads, curbs and sidewalks are set forth in Exhibit 1 § 155.33.
(D) Frontage or service roads separate local traffic from the higher speed through-traffic of major transportation arteries. Frontage or service roads may also be required by the Plan Commission to be located outside the right-of-way of arterial roads and streets when the average daily traffic exceeds 8,000 vehicles on two-lane roads and 15,000 vehicles on four-lane roads and the speed limit exceeds 40 mph, or when the number of curb cuts creates a traffic hazard or major flow impediment. Design of frontage or service roads shall be based on providing access to the property, maintaining circulation of traffic within the subdivision and providing for parking requirements and surface drainage.
(E) Auxiliary lanes must conform to the approved plans and specifications.
(F) Intersections involving more than four legs (approaches to the intersection) should be avoided. Three-legged intersections may be used wherever appropriate, particularly in residential areas. Right-angle intersections must be used wherever practicable. When local roads and streets intersect arterial or collector roads, the angle of intersection of the road centerlines may not be less than 75 degrees.
(1) Intersections must be approached on all sides by near level areas. Where the grade exceeds 7% these level areas must have a minimum length of 50 feet (measured from the intersection of the centerline) within which no grade may exceed a maximum of 2%.
(2) Design of curb or edge or pavement radii shall conform to the applicable standards adopted by the Board of County Commissioners.
(3) Minimum sight distance at intersections should be sufficient to avoid the hazard of a collision between a vehicle starting from a “stop” position and the vehicle approaching the intersection from the left or right.
(G) All plans shall conform to the current design standards as set forth in this chapter. Private roads which are installed shall conform to the thickness standards for roads as set forth in this chapter.
(H) The primary access road in the subdivision must be of adequate width and design to accommodate emergency vehicles and regular daily traffic, including being above the 100-year FEMA flood elevation, and the sight distance for any entrances of the subdivision onto a public road or street shall be adequate.
(I) All roads within the subdivision must be above the 100-year FEMA flood elevation.
(Ord. 18-2007, passed 12-18-2007; Ord. passed 6-12-2008)