(a) General Provisions. The arrangement, character, extent, width, grade and location of all streets shall conform to the Official Thoroughfare Plan or subsequent amendments thereof, and shall be considered in their relation to existing and planned streets, to topographical conditions, to public convenience and safety and in their appropriate relation to the proposed uses of the land to be served by such streets. As to arrangement, the subdivider shall provide within the boundaries of the subdivision plat the necessary right of way for the widening, continuance or alignment of such streets in conformity with the Official Thoroughfare Plan by one of the following methods:
(1) The dedication of the necessary right of way for the continuation, extension or connection of any present or planned thoroughfare.
(2) When subdividing the land fronting on an existing road or street, not designated on the Official Thoroughfare Plan as equal to or of greater importance than an auxiliary street, a reasonable provision shall be made for necessary rights of way or easements for traffic, utilities and drainage.
(b) Major Traffic Arteries and Physical Barriers.
(1) Traffic arteries. Where a subdivision abuts or contains an existing or proposed street of equal or greater width than a secondary thoroughfare as shown on the Official Thoroughfare Plan, the Commission may require any of the following:
A. Marginal access streets.
B. Reverse frontage with planting contained in a nonaccess reservation along the rear property line or a planting strip of a minimum width of twenty feet on the rear of the lots with no vehicular access across such strip.
C. Deep lots with rear service alleys.
D. Such other treatment as may be necessary for adequate protection of residential properties and to afford separation of through and local traffic.
(2) Physical barriers. Where a subdivision borders on or contains a railroad right of way or limited access highway right of way, the Commission may require a street approximately parallel to and on each side of such right of way at a distance suitable for necessary traffic circulation.
(c) Arrangement.
(1) Traffic. Minor streets as defined herein and on the Official Thoroughfare Plan shall be so laid out that their use by through traffic will be discouraged.
(2) Access to adjacent property. The street layout shall make provision for the proper projection and continuance of streets and all utilities into adjacent unsubdivided acreage where it is deemed appropriate and desirable by the Commission. Reserve strips controlling access to streets shall be prohibiting.
(3) Future street system. Where the plat to be submitted includes only part of the tract owned by the subdivider, the Commission may require a sketch of a tentative future street system for the unsubdivided portion.
(d) Alignment.
(1) Horizontal.
A. Jogs. No street layouts with center line offsets of less than 125 feet shall be permitted without consent of the Commission.
B. Angle of intersections. Streets shall be laid out so as to intersect, as nearly as possible, at right angles and no street shall intersect any other street at less than sixty degrees.
C. Intersection approaches. Approaches to street intersections shall be straight for a distance of at least 100 feet from the center line of the street intersected.
D. Reverse curves. A total tangent of at least 200 feet long shall be introduced between reverse curves on all but minor and marginal access streets.
(2) Vertical; grade at intersection. Approaches to intersections shall be reduced to a grade not exceeding three percent for a distance of at least 150 feet. The Commission may modify this requirement when an unreasonable hardship would result from its strict enforcement.
(e) Classification. The Commission approving each street in a proposed subdivision shall be governed by the following standards:
(1) For main and secondary thoroughfares, the minimum radius or curvature shall be 300 feet on the center lines; for minor streets, 100 feet and for local service streets, seventy-five feet.
(2) All horizontal curves shall show the complete function of such curves and each P.C. and P.T. shall be stationed.
(3) Profiles and grades of all proposed streets shall be the center line grades of the respective streets and shall be indicated in complete detail in the profiles and referenced to the stationing shown on the plan.
The maximum grades shall not exceed seven percent for main and secondary thoroughfares or fourteen percent for minor or local service streets. The minimum grade for all classifications of streets shall not be less than four-tenths of one percent. All major changes in grade shall be connected by vertical curves of a minimum length equal to fifteen times the algebraic difference in the rate of grade for thoroughfares, and one-half this minimum length for minor local service streets.
The P.C. and P.T. of all vertical curves shall be stationed and elevations shall be shown at least every twenty-five feet within the limits of the vertical curves.
(f) Corner Radii at Intersections. Property lines at street right-of-way intersections shall be rounded with a radius of twenty-five feet or of a greater radius where the Commission may deem it necessary.
(Ord. 69-35. Passed 10-27-69.)
(g) Dead end Streets.
(1) Permanent. Dead end streets or cul-de-sacs, designed to be so permanently, shall not be longer than 600 feet and shall be provided at the closed end with a turn-around having a street property line diameter of at least 100 feet. The street right-of-way lines and the 100-foot diameter turnaround should be joined by tangent arcs of a fifty-foot minimum radius.
(2) Temporary.
A. Where streets are extended to the boundary of a subdivision to provide for their proper continuance at such time as the adjacent land is subdivided, they may be terminated within the right of way provided a temporary concrete or black top "T" turn around is constructed at least twenty-two feet wide the complete width of the right of way and located within the last thirty feet of the street pavement.
B. If a street extends only one lot in depth past a street intersection, no turn-around is required.
(Ord. 89-16. Passed 3-13-89.)
(h) Half-streets. Half-streets shall be prohibited except under one of the following conditions:
(1) There exists a half-street which should logically be continued to a reasonable intersection.
(2) There exists a dedicated or platted half-street adjacent to the tract to be subdivided; the other half shall be platted if deemed necessary by the Commission.
(Ord. 69-35. Passed 10-27-69.)