(a) Generally. The arrangement, character, extent, widths and locations of all streets shall conform to the transportation plan and shall be considered in their relation to existing and planned streets, to topographical conditions, to public convenience and safety and to their appropriate relation to the proposed uses of the land to be served by such streets. In designing a street system, the subdivider shall be guided by the following principles:
(1) Adequate vehicular and pedestrian access shall be provided to all parcels.
(2) Local street systems shall be designed to minimize through-traffic movement.
(3) Local street systems shall be logical and comprehensible.
(4) The arrangement of local streets shall permit economical and practical patterns, shapes and sizes of development parcels.
(b) Layout and Design.
(1) Streets shall be classified as expressways, and freeways, major arterial or trunk line roads, collector or feeder streets, local streets or alleys, industrial and commercial. Street pavement, number of lanes and right-of-way widths shall not be less than as follows:
Street Type | Minimum Pavement | Number of Lanes | Right-of-way |
Expressways and freeways | 48 feet or more | 4 or more | 150 feet |
Major arterial or trunk lines | 24 to 48 feet | 2 to 4 | 80 feet |
Collector streets or feedes | 24 to 48 feet | 2 to 4 | 50 to 80 feet |
Local streets | 20 to 24 feet | -2- | 40 to 50 feet |
Alleys (industrial and commercial) | 16 feet | 20 feet |
The standards listed above may be increased or decreased where necessary, as approved by the Planning Commission. The minimum pavement and the rights- of-way are listed in ranges due to the varied topography of the City. In cases where only little difficulty is encountered, the maximum of the range shall be required; in the hilly areas, where greater difficulties would be encountered, the minimum of the range shall be required.
(2) When any proposed subdivision fronts on or has access to a State road, the Commission shall consult with the State Department of Highways concerning the effect of the subdivision on the State road.
(3) Whenever a proposed subdivision contains any part of a street so designated on the transportation plan, such part of such street shall be platted by the subdivider in the location and at the width indicated in the comprehensive plan.
(4) Where appropriate to the design, new streets shall generally be continuous in alignment with existing streets with which they are to connect.
(5) Proposed streets shall be extended to the boundary lines of the proposed subdivision with temporary turnarounds, unless such extension is not feasible because of topography or other physical conditions or unless, in the opinion of the Commission, such extension is not necessary or desirable for the coordination with existing streets or the most advantageous development of adjacent tracts.
(c) Grades.
(1) Grades shall conform as closely as possible to the original topography and shall be designed to produce usable lots and reasonable grades.
(2) Grades shall be arranged so as to obtain as many building sites as possible at or above the grade of the streets abutting the building.
(3) Grades, wherever feasible, shall not exceed the following, with due allowance for reasonable vertical curves:
Street Type | Percent Grade |
Arterial | 5 |
Collector | 10 to 15 |
Minor | 10 to 15 |
Marginal access | 5 |
The Commission may permit steeper grades in special circumstances.
(4) No street grade shall be less than 0.50 percent.
(5) Sight distances over grades shall not be less than 150 feet. Sight distances around curves shall not be less than 150 feet. A combination of steep grades and sharp curves shall be avoided.
(6) Grades at street intersections shall be held to a maximum of two percent (2%) for a distance of seventy-five feet in any direction from the point of intersection of the street centerlines.
(d) Horizontal Alignment.
(1) A tangent shall be introduced between reverse curves and shall be at least 100 feet in length on local and collector streets.
(2) When continuing street lines of collector streets deflect from each other at any one point by more than ten degrees, they shall be connected by a curve with a radius at the inner street right-of-way line of not less than 350 feet; where continuing street lines of arterial streets deflect from each other by more than five degrees, they shall be connected by a curve with a radius of not less than 800 feet.
(3) Dead-end streets shall be prohibited except as stubs to permit future extensions to adjoining tracts or where necessitated by topography or where, in the opinion of the Commission, they are appropriate for the type of development contemplated and are designed as culs-de-sac.
(4) Half-streets shall be prohibited, except where essential to the reasonable development of the subdivision in conformity with the other requirements of these Subdivision Regulations and where the Commission finds it shall be practicable to require the dedication of the other half when the adjoining property is subdivided. Wherever a half-street is adjacent to a tract to be subdivided, the other half of the street shall be platted within such tract.
(5) Subdivisions that adjoin or include existing streets that do not conform to the standards of this section or of the transportation plan shall be required to dedicate additional width along either one or both sides of such streets of inadequate width so as to bring them up to standards.
(6) Reserve strips of land controlling access to streets shall be prohibited except where their control is definitely placed in the City under conditions approved by the Commission.
(7) Where a subdivision abuts or contains an existing or proposed arterial street or railroad right-of-way, the Commission may require the separation of local and through-traffic. This shall be achieved by one of the following means:
A. A marginal access street, separated from the arterial street by a planting strip; or
B. Reverse frontage lots, with the lots fronting on an interior local street and having a nonaccess reservation along the rear property line.
Where either of the aforementioned arrangements are used, the statement "Vehicular Ingress and Egress Ristricted" shall be shown with limits on the final subdivision plat and no driveways shall have direct access to the arterial street.
(8) The street system layout shall be so designed as to preserve, wherever possible, natural features such as trees, groves, creeks, hilltops, scenic views and historical landmarks; and to preserve, wherever possible, the natural lay of the land and disposition of the topsoil.
(9) Proposed streets which are clearly aligned with an existing street shall bear the name of the existing street. In no other case shall the names of the proposed streets duplicate or be phonetically similar to an existing street name, irrespective of the suffix "street," "avenue," "place," or other. In the naming of developments, streets, etc., developers are encouraged to make use of local names and historical associations.
(e) Intersections.
(1) Streets should be laid out so as to intersect as nearly as possible at right angles; and no street shall intersect with any other street at less than sixty degrees. Any change in street alignment to meet this requirement shall occur at least eighty feet from the intersection.
(2) Multiple-intersections involving junctions of more than two streets shall be avoided.
(3) Clear sight triangles of fifty feet, measured along street right-of-way lines from their points of junction, shall be provided at all intersections; and no building, structure, grade or planting higher than three feet above the centerline of the street shall be permitted within such sight triangles.
(4) Streets entering opposite sides of another street shall be laid out either directly opposite one another or with a minimum offset of 150 feet between their centerlines.
(5) Minimum curb radii at street intersections shall be twenty feet.
(6) Where a proposed subdivision abuts or contains an existing or proposed arterial street, the number of intersections with the arterial street shall be kept to a minimum. To the fullest extent possible, intersections with arterial streets shall be located not less than 650 feet apart measured from centerline to centerline.
(f) Culs-de-sac.
(1) Cul-de-sac streets, permanently designed as such, shall not exceed 500 feet in length. In circumstances where physical features of the site make longer culs-de-sac necessary, the Commission may require turnaround areas at intermediate points.
(2) Cul-de-sac streets shall be provided at the closed end with a paved turnaround having a minimum radius of eighty feet to the outer pavement edge or curb line and a radius of 100 feet to the right-of-way line.
(3) A suitable turnaround may be required by the Commission when a street is temporarily dead-ended over 151 feet from its nearest intersection.
(4) A cul-de-sac may be designed in the shape of a letter "T" when the topography makes the choice advisable in the opinion of the Commission. The base of the "T" shall be a street not less than twenty feet wide and the cross-bar at the end of the "T" shall be a street of not less than sixteen feet wide and extending beyond the outer boundaries of the base street not less than twenty feet in both directions. Permission to use the "T" design of cul-de-sac shall be granted or denied at the sole descretion of the Commission.
(g) Alleys.
(1) Alleys shall be provided in commercial and industrial districts; except, that the Commission may waive this requirement where other definite and assured provision is made for service access. Alleys shall not be provided in other locations unless required by special conditions.
(2) The minimum width of an alley shall be twenty feet.
(3) Alley intersections and sharp changes in alignment shall be avoided; but, where necessary, corners shall be cut off sufficiently to permit safe vehicular movement.
(4) Dead-end alleys shall be avoided; but, if unavoidable, shall be provided with adequate turnaround facilities at the dead-end, as determined by the Commission.
(h) Dedication of Right-of-Way for Existing Streets. Subdivisions platted along existing streets shall dedicate additional right-of-way if necessary to meet the minimum street width requirements set forth in subsection (b) hereof.
(1) The entire minimum right-of-way shall be dedicated where the subdivision is on both sides of an existing street. When the subdivision is located on only one side of an existing street, one half of the required right-of-way width, measured from the centerline of the existing roadway, shall be dedicated.
(2) The dedication of one half of the right-of-way for proposed streets along the boundaries of land proposed for subdivision shall be prohibited.
(i) Erosion Protection.
(1) All area between the edge of pavement and the right-of-way shall be burlapped and pegged; except for sidewalks and steep drainage areas, where other treatment is necessary.
(2) To protect ditches and other areas from erosion, the following protective measures shall be required:
Grade of Ditch | Required Protection |
Less than 1% | Seed, fertilize and mulch entire ditch and slopes to establish protective vegetative cover. |
1% to 5% | Seed, fertilize, burlap and peg the invert and sides to top 2:l slope |
5% to 7% | Paved invert and paved slope to 6 inches above maximum flow depth, with reinforced concrete 4 inches thick. Seed, fertilize, burlap and peg the street right-of-way. |
All over 7% | Seed and pave as above, but with alternate side diagonal baffles at centers about 3 to 4 feet to retard flow. |
(3) All seeding and fertilizing shall be done in conformance with the following standards as minimum requirements:
Rate Per Seed Mixture 1000 Square Feet Rate Per Acre 1 Tall fescue 1.5 lbs. 60 lbs. Kentucky blue- grass l.0 lbs. 40 lbs. 2 Tall fescue 1.0 lbs. 40 lbs. Crown vetch 0.5 lbs. 20 lbs. Kentucky blue- grass 1.0 lbs. 40 lbs. 3 Tall fescue 0.75 lbs. 30 lbs. Perennial rye grass 0.75 lbs. 30 lbs. Kentucky blue- grass l.0 lbs. 40 lbs. Fertilizer or Organic Equivalent 1 10-10-10 25 lbs. 1,000 lbs. 2 12-12-12 20 lbs. 800 lbs. Rate Per Mulch Mixture 1000 Square Feet Rate Per Acre Straw 100 lbs. 2 tons Lime Add lime to raise pH to minimum 6.0. |
(1970 Code Sec. 28.1-24)