All streets, as designated and labeled upon said proposed plat, shall be graded, constructed and surfaced in accordance with construction plans and specifications submitted by the applicant and approved as required by relevant sections of this chapter. (Refer to “construction standards”.)
(A) Minimum pavement width.
(1) The minimum width of local street pavement, including gutters and curbs, shall be 28 feet measured from back to back of curbs. Gutters and curbs shall be constructed according to the requirements of this chapter.
(2) The minimum width of marginal access street pavement, including gutters and curbs shall be 24 feet.
(B) Maximum grades.
(1) The maximum grade of expressways and primary thoroughfares shall not exceed 3%.
(2) The maximum grade of secondary thoroughfares, parkways and collector streets shall not exceed 4%.
(3) The maximum grade for local streets, marginal access streets and cul-de-sacs shall not exceed 7%.
(C) Minimum grades.
(1) The minimum grade of concrete streets and gutters shall be 0.5%.
(2) The minimum grade for all other types of streets and gutters and for ditches shall be 0.8%.
(D) Street alignment.
(1) Profile grades for thoroughfares shall be connected by vertical curves of a minimum length equivalent to 20 times the algebraic difference between the rates of grade, expressed in feet per hundred. Profile grades for collector, local streets and cul-de-sacs, shall be 15 times the algebraic difference.
(2) The minimum radii of center curvature for streets shall be:
(a) Expressways and primary thoroughfares: 475 feet or 12 degrees;
(b) Secondary thoroughfares: 300 feet or 19 degrees;
(c) Collector streets, local streets, marginal access streets and cul-de-sacs: 125 feet or 46 degrees; and
(d) Streets shorter than 500 feet: 100 feet or 58 degrees.
(3) The minimum tangent between reversed curves shall be:
(a) Expressways, primary and secondary thoroughfare: 200 feet; and
(b) Collector streets, and as required by the Commission on all other streets: 100 feet.
(E) Visibility requirements.
(1) Minimum vertical visibility measured from four and one-half feet (eye level) to 18 inches (tail light) height, within traveled lanes shall be:
(a) Expressways, primary and secondary thoroughfares: 500 feet;
(b) Collector streets: 300 feet;
(c) Local streets, marginal access streets and cul-de-sacs: 200 feet; and
(d) Streets shorter than 500 feet: 100 feet.
(2) Minimum horizontal visibility measured on centerline shall be:
(a) Expressways, primary and secondary thoroughfares: 300 feet;
(b) Collector streets: 200 feet; and
(c) All other streets: 100 feet.
(F) Intersections.
(1) Street curbs shall be rounded by radii of sufficient length to permit smooth flow of traffic. Minimum allowable radius for street curbs will be 20 feet.
(2) Street intersections shall be as nearly at right angles as is possible, and no intersection shall be at an angle of less than 60 degrees.
(3) Street jogs with centerline offsets of less than 125 feet shall be permitted.
(G) Site distances at intersections. The following paragraph shall be required as a provision of the covenants of all final plats: no fence, wall, hedge or shrub planting, which obstructs sight lines at elevations between two and six feet above the street, shall be placed or permitted to remain on any corner lot within the triangular area formed by the street property lines and a line connecting points 25 feet from the intersection of said street lines or, in the case of a rounded property corner, from the intersection of the street lines extended. The same sight line limitations shall apply to any lot within ten feet from the intersection of a street line with the edge of a driveway pavement or alley line. No tree shall be permitted to remain within such distances of such intersections unless the foliage line is maintained at sufficient height to prevent obstruction of such sight lines.
(H) Special requirements for non-residential subdivisions. Special requirements for non-residential subdivisions shall be as follows.
(1) Where streets are designed to serve industrial or commercial subdivisions or sites, or other developments requiring service by many heavy commercial vehicles, the minimum thicknesses will be appropriate for the anticipated traffic.
(2) Light industrial streets with heavy commercial vehicles in excess of 100 per day in any lane will be designed as collectors or secondary thoroughfares.
(3) Heavy industrial streets with heavy commercial vehicles in excess of 200 per day in any lane will be designed as secondary thoroughfares.
(4) Special pavement requirements in excess of minimum secondary thoroughfare design standards for heavy commercial vehicles in excess of 400 per day will be submitted by the applicant for approval of the Commission.
(5) HEAVY COMMERCIAL VEHICLES (HCV) are defined as two-axle, six-tired and heavier trucks.
(2004 Code, § 4-409)