(a) Design and Arrangement.
(1) The arrangement of streets in new subdivisions shall make provision for the continuation of the principal existing streets in adjoining areas, or their proper projection where adjoining land is not subdivided, insofar as they may be deemed necessary for public requirements. Every subdivision shall have access to a public right of way.
(2) The street and alley arrangement shall be such as not to cause hardship to owners of adjoining property when they plat their own land and seek to provide for convenient access to it. Residential streets shall be designed so as to discourage through traffic, but offset streets should be avoided.
(3) The angle of an intersection between minor streets and major streets should not vary by more than ten degrees from a right angle. All other streets should intersect each other as near to a right angle as possible.
(4) The minimum curb radius at intersections subject to the approval of the Municipal Engineer shall be twenty feet. Curbs shall be required for all areas as noted in Chapter 1117.
(5) Residential streets shall be designed to discourage through traffic which may otherwise use secondary or major highways, and whose origin and destination are not within the subdivision. Residential streets extending for considerable distance, parallel to any secondary or major street, should be avoided.
(b) Alignment.
(1) Vertical.
A. For main thoroughfares, profile grades shall be connected by vertical curves of a minimum length in multiples of fifty feet approximately equivalent to twenty times and the algebraic difference between the rates of grade, expressed in feet per hundred; for secondary and minor streets and alleys, fifteen times.
B. For slope areas where the average topographic slope is fifteen percent (15%) or greater refer to Hillside Standards, Chapter 1121.
(2) Minimum horizontal.
A. The radii of centerline curvatures are:
Degrees | Feet | |
Primary thoroughfares | 12 | 475 |
Secondary thoroughfares | 19 | 300 |
Minor streets | 20 | 200 |
Streets shorter than 500 feet | 58 | 100 |
A minimum tangent of 100 feet shall be introduced between reverse curves.
B. For slope areas where the average topographic slope is fifteen percent (15%) or greater, refer to Hillside Standards, Chapter 1121.
(3) Visibility requirements.
A. Minimum vertical visibility shall be measured four and one-half feet, eye level to taillight, eighteen inches above ground level.
Street | Visibility Distance (feet) |
Primary thoroughfares | 500 |
Secondary thoroughfares | 300 |
Minor streets | 200 |
Streets shorter than 500 feet | 100 |
For slope areas where the average topographic slope is fifteen percent (15%) or greater, refer to Hillside Standards, Chapter 1121.
B. Minimum horizontal visibility measured on the centerline, shall be:
Street | Visibility Distance (feet) |
Primary thoroughfares | 500 |
Secondary thoroughfares | 300 |
All other streets | 100 |
For slope areas where the average topographic slope is fifteen percent (15%) or greater refer to Hillside Standards, Chapter 1121.
(c) Street Type and Width.
(1) Major thoroughfare streets. The width of all major thoroughfares shall conform to the width designated on the Major Highway Plan of the Municipality.
(2) Minimum right of way. The minimum right-of-way width for local streets shall be fifty feet unless stated differently on the Major Highway Plan of the Municipality.
(3) Local streets. The minimum width of local streets shall be fifty feet and the pavement widths shall be in accordance with the provisions of Chapter 1117
, except where there are unusual topographical or other physical conditions, the Commission may require greater or lesser widths for rights of way and pavements for local streets.
(4) Location. When a proposed subdivision is adjacent to or contains a State highway, the developer and Commissioners should seek information from the State Department of Transportation as to the status of such highway in reference to width and direction, and also to access of such highway.
(5) Half-streets. Dedication of new half-streets shall not be permitted. Where a dedicated or platted half-street or alley exists adjacent to the tract being subdivided, the other half shall be platted, if deemed necessary by the Commission.
(6) Cul-de-sacs. Each cul-de-sac shall be provided with a turnaround having a minimum right-of-way radius of fifty feet. The outside of the road surface within the turnaround right of way shall have a minimum radius of thirty-eight feet. The maximum length for a cul-de-sac shall be 600 feet. The minimum frontage or lot width shall be measured at the building line on any cul-de-sac.
(7) Dead-end streets. Dead-end streets, designated to be so permanently, shall not be permitted. Any dead-end street of a temporary nature, if longer than 200 feet or fronted by existing lots, shall have a surfaced turning area equal in diameter to the width of such street at its termination.
(8) Marginal access streets.
A. Where a subdivision adjoins a major street, and the greater dimension of the block fronts along such major street or highway, a marginal access street shall be designated to provide access to subdivided parcels. Points of access to the major street or highway shall be kept to a minimum interval of 1,000 feet.
B. A planting strip of a minimum width of twenty feet shall be provided between the pavement of the major street or highway and the pavement of the marginal access street.
C. The minimum width of the marginal access right of way shall be thirty feet.
(9) Street grades. Street grades shall not exceed the following with due allowances for reasonable vertical curves:
Street | Grade Percentage |
Primary thoroughfares | 6 |
Secondary thoroughfares | 10 |
Minor streets and alleys | 12 |
Streets shorter than 500 feet and cul-de-sacs | 15 |
No street grade shall be less than one percent (1%).
(10) Street name. New names are required for new streets in unincorporated areas; the names shall meet with the approval of the Planning Commission. No name shall be similar in spelling or pronunciation to that of an existing street in a postal zone. Streets which are essentially contiguous shall have the same name.
(11) Acceptance of streets.
A. The approval of a plat by Council shall be deemed to be an acceptance of the dedication of any public street, road or highway dedicated in such plat.
B. The Municipal Engineer shall check the construction by stages and if the Engineer finds that such street is constructed in accordance with the specifications set forth on the approved plat and that such street is in good repair, then such finding, endorsed on the approved plat, shall constitute an acceptance of the street for public use by the Municipality.
(Ord. 1389. Passed 1-10-80.)