The following shall govern the design of all street improvements within the city:
(A) Side slopes should not be steeper than three horizontal to one vertical within the limits of the dedicated right-of-way.
(B) The alignment and design of streets should be such that major thoroughfares have a design speed of 40 miles per hour, collector, industrial and commercial streets have a design speed of 35 miles per hour, and residential streets have a design speed of 30 miles per hour.
(C) Horizontal alignments.
(1) The following minimum centerline radii shall be used in the design of all street construction:
Type Street | Minimum Radius |
Collector, industrial or commercial | 600 ft. |
Local, residential | 200 ft. |
(2) The minimum centerline radii for major thoroughfares shall comply with AASHTO's A Policy on Geometric Design of Highways and Streets, 1984, Values for Superelevation Rate Related to Curvature on High Speed Highways for e max = 0.06 ft./ft.
(3) Reverse circular curves having a common tangent shall be separated by a tangent section in accordance with the following table:
Minimum Tangent | |
Type Street | Between Curves |
Major thoroughfare | 200 ft. |
Collector, industrial or commercial | 100 ft. |
Local, residential | 50 ft. |
(4) The minimum radius for the back of curb on a cul-de-sac shall be 50 feet.
(5) The minimum radius for curb returns at intersections shall be as follows:
Type Street | Maximum Grade |
Major thoroughfare, collector, industrial or commercial | 30 ft. |
Local, residential | 15 ft. |
(6) Streets shall conform to the comprehensive plan as adopted. Where developer contends that such is not feasible, facts and data must be submitted to, and approved by the Planning and Zoning Commission.
(D) Vertical alignment.
(1) No streets shall be designed or constructed to a grade of less than 0.5 of 1%.
(2) No streets shall be designed or constructed with grades in excess of the following:
Type Street | Maximum Grade |
Major thoroughfare | 6.0% |
Collector, industrial or commercial | 8.0% |
Local, residential | 10.0% |
(3) All streets within 50 feet of an intersection shall have a maximum 2% grade, with the following exceptions:
(a) On a major thoroughfare intersecting a collector or a local street;
(b) On a collector street intersecting a local street.
(4) In order to maintain adequate sight distances, the following minimum lengths of vertical curves shall be required:
Minimum Vertical | |
Type Street | Curve Length |
Major thoroughfare | 80 ft. for each algebraic percent difference in grade |
Collector, industrial or commercial | 60 ft. for each algebraic percent difference in grade |
Local, residential | 50 ft. for each algebraic percent difference in grade |
(E) Street widths and cross sections shall be per the Typical Sections identified in the City's Master Thoroughfare Plan.
(F) Any newly constructed local street or minor collector of 1,000 linear feet or more shall meet the following curvilinear requirements, unless otherwise approved by the Director of Public Works:
(1) A minimum centerline deviation of 50 feet from the projected straight line path between beginning and ending points of the street.
(2) A minimum of 40% of the length of the street must be on a curve.
(3) A maximum curve radius of 1,200 feet for local streets and 2,500 feet for collectors.
(4) The street must meet all requirements outlined in § 154.080.
(5) Developer/applicant shall provide an exhibit detailing how proposed development meets the requirement for curvilinear streets prior to any plat submittal.
('68 Code, App. B, § 5.01) (Ord. 8-1989-34, passed 8-8-89; Am. Ord. 04-2022-40, passed 4-26-22; Am. Ord. 01-2023-04, passed 1-24-23)