§ 11-90. Street design criteria for land development.

All design criteria for streets and roads in land developments are contained in Table 1 and Table 2 of Appendix A and as follows. The traffic classification and soil types described in Appendix A of this chapter, and as follows, shall be used to determine the minimum pavement structure for each proposed street or road.

(1)

Extensions: All street and road extensions shall meet all design standards unless approved by the County Judge in writing.

(2)

Substandard widths: Land developments that adjoin substandard existing county roads shall meet the requirements contained in section 11-95.

(3)

Street names and numbers: Names and numbers of streets and roads shall be consistent with natural alignment and extensions of existing streets or roads. New street or road names must be used which will not duplicate or be easily confused with existing names and must be approved by the County 9-1-1 Data Base Coordinator. Each development shall be reviewed by the 9-1-1 Data Base Coordinator to assign 9-1-1 addresses to each lot and said lot addresses shall be shown on the Final Plat.

(4)

Curb and gutter: The curb and gutter, if required or if used, shall be designed and constructed in accordance with the requirements of this Article. Curb and gutter sections are encouraged in industrial and commercial areas. Also, the required right-of-way may be reduced in curb and gutter sections.

(5)

Tangents: A straight tangent at least one hundred (100) feet long shall separate reverse curves.

(6)

Temporary cul-de-sac: Temporary cul-de-sac designed to provide future connections with adjoining undeveloped areas shall provide a temporary turnaround easement and shall be designed in a manner which will prevent excessive accumulation of runoff water at the dead end. However, said cul-de-sac shall not exceed one thousand two hundred (1,200) feet in length, measured to the outer edge of the turnaround from the edge of the right-of-way of the existing county road which serves as access to the land development.

(7)

Permanent cul-de-sac: Streets with permanent cul-de-sacs shall not exceed twelve hundred (1,200) feet in length, measured to the outer edge of the turnaround, from the edge of the right-of-way of the existing county road which serves as access to the land development. All turnarounds shall have radii as follows:

a.

Hard surface pavements: Surface radius with curb and gutter at forty-five (45) feet; without curb and gutter at fifty (50) feet. Right-of-way with curb and gutter shall be fifty (50) feet; without curb and gutter, sixty (60) feet.

b.

Gravel surface: Driving surface radius shall be at fifty (50) feet with a sixty-foot right-of-way.

Alternative methods that may be used to conform to the cul-de-sac lengths, include but are not limited to:

(a)

Divided entrances;

(b)

Emergency access only roads, with or without gating; and/or

(c)

Bonds or other adequate surety to insure future improvement of alternative access roads.

Such alternative methods shall be approved by the County Judge and the County Fire Marshal and such approval shall not be unreasonably or arbitrarily withheld.

(8)

Intersections: Streets shall be designed to intersect as nearly as possible at right angles, provided that no street shall intersect at any other street at less than seventy-five (75) degrees.

a.

Intersections of local streets shall have a minimum driving surface radius of thirty (30) feet.

b.

Intersections of collector or high-density residential streets shall have a minimum driving surface radius of forty (40) feet.

c.

All corner radii must be shown on the street improvement plan.

(9)

Street grades: Street grades shall conform to the following:

a.

Street grades for arterial highways should not exceed ten (10) percent; grades for all other classifications of streets should not exceed twelve (12) percent.
Exceptions: Grades of up to seventeen (17) percent will be accepted for a distance not to exceed three hundred (300) feet and in such cases concrete surfacing with curb and gutter may be required based on storm drainage provisions.)

b.

All changes in grade shall be connected by a vertical curve of a reasonable radius to assure adequate sight distance.

c.

In approaching intersections, there shall be a suitable leveling of the street grade, generally not exceeding five (5) percent, for a distance of not less than fifty (50) feet from the nearest line of the intersecting street.

d.

To the extent possible and practical, all minor streets and driveways should be sloped away from the major street or County road to prevent water and debris from being deposited on the major street or road.

e.

The grade within the intersection should be as level as possible, and consistent with proper provisions for drainage.

(10)

In platting lands abutting federal and state highway or other arterial traffic ways, every effort shall be made (a) to cushion the adverse impact of heavy or high-speed traffic on such lands, especially where used for residential purposes; (b) to minimize interference with through traffic operations; and (c) to reduce vehicular and pedestrian accident hazards.

(11)

Private roads: Privately maintained roads may be established in certain circumstances as follows:

a.

Subdivisions containing four (4) or fewer single-family residential lots may elect to establish a private road to serve the lots, provided the road right-of-way connecting the lots to the county road is a minimum width of thirty (30) feet.

b.

Subdivisions containing five (5) to ten (10) single-family residential lots may elect to establish a private road to serve the lots. However, the road connecting the lots to the county road must be constructed to the specifications noted below. Before final plat approval, the road superintendent shall visually inspect the road to ensure that general compliance with the specifications noted below have been met:

1.

Fifty-foot road right-of-way;

2.

Fourteen-foot road wide road surface with eight-inch compacted SB-2, or six-inch compacted SB-2 on a prepared subgrade;

3.

Four-foot shoulder;

4.

Four-foot ditch;

5.

Twelve (12) percent maximum grade;

6.

Fifty-foot minimum cul-de-sac radius at the end;

7.

Drainage provided with adequate pipes and culverts as necessary.

c.

A development that utilizes, in whole or in part, a private road for access shall be referred to as a "private road development" or "PRD."

d.

The plat shall note, in a noticeable fashion, the following, "NOTICE: THIS ROAD IS NOT CONSTRUCTED TO THE COUNTY STANDARD. THE MAINTENANCE OF THE ROAD IS THE RESPONSIBILITY OF THE CURRENT AND FUTURE PROPERTY OWNERS. THE ROAD WILL NOT BE ACCEPTED FOR MAINTENANCE BY THE COUNTY UNTIL IT IS CONSTRUCTED TO THE COUNTY STANDARD AT THE EXPENSE OF THE PROPERTY OWNERS."

e.

In cases where the private road easement serves at least three (3) homes and is at least five hundred (500) feet in length (measured from the intersection of the County/Public Road ROW to the furthest existing or proposed residential structure) the following shall be applicable:

1.

The developer shall be responsible for paying the county road department for the purchase and installation of a sign indicating that the road is maintained by the property owners.

2.

The developer shall file for public record a "Private Road Maintenance Disclosure Statement" (provided in Part II, Technical Provisions, Appendix C).

3.

New private road subdivisions must have their proposed private roads named according to 9-1-1 procedure (submittal and approval of the proper paperwork through the 9-1-1 Operations Office) prior to the final subdivision plat approval. The private road subdivision developer or applicant shall be responsible for erecting the street sign stating the name of the private road prior to final plat approval. The sign placement must be inspected by the 9-1-1 Operations Office or the County Planning Office, and be in accordance with U. S. Department of Transportation Manual on Uniform Traffic Control Devises.

f.

All private road subdivisions shall be required to comply with Appendix A regarding sight distances when a private road intersects with a county or public road.

g.

Any gravel private road that intersects with a paved county or public road at such an incline such that the gravel will be washed or carried out onto the county or public road must be paved for a distance up to 30 feet. A lesser amount may be required depending on the gradient or condition of the drive.

(Ord. No. 91-9, Art. 1, § 3.05, 4-11-91; Ord. No. 99-32, Art. 1, 7-8-99; Ord. No. 2006-43, Arts. 1—3, 7-13-06; Ord. No. 2008-19, Art. 1, 4-15-08; Ord. No. 2010-74, Art. 1, 12-16-10; Ord. No. 2011-16, Art. 1, 3-10-11)