§ 6.03.14. Road and street design standards.

All improvements and construction activities required under these regulations shall take place according to plans approved by the county engineer. The plans submitted to the county engineer shall bear the signature of a Florida licensed professional engineer responsible for the project as defined by Chapter 471, Florida Statutes. Design and construction must be consistent with the Florida Manual of Uniform Standards for Design, Construction and Maintenance for Streets and Highways. (Green Book)

1.

Specific requirements:

a.

Alignment and geometry: Streets will intersect at angles no less than 75 degrees. Unaligned intersections shall be separated by a minimum of 150 feet between center lines. Intersections involving more than four basic street legs or approaches shall be prohibited.

b.

Right-of-way:

i.

All roads and streets shall have sufficient right-of-way to conform to Green Book standards for clear zones and other requirements, and to accommodate drainage requirements. If such requirements exceed the minimum width specified in item b below, that width shall be the acceptable minimum.

ii.

Subdivision streets that are to be dedicated to the public for ownership and maintenance shall have dimensions as specified in Table 6-03-01 per the functional classifications defined in section 6.03.03:

Table 6-03-1
Minimum R/W Width →	50'	66'	80'
Collector			X
Major Local	X*	X*
Minor Local	X

 

* For major local roads servicing less than 50 lots the minimum right-of-way width shall be 50'. For major local roads servicing 50 lots or more the minimum right-of-way shall be 66'.

c.

Cul-de-sacs and turnarounds:

i.

Turnarounds are not required on streets 200 feet or less in length and serving six or less dwelling units;

ii.

Turnarounds will be used on dead-end streets 300 feet or less in length that do not comply with (a) above. Turnarounds must comply with;

iii.

AASHTO latest edition ("A Policy on Geometric Designs of Highways and Streets");

iv.

A cul-de-sac shall be used on streets longer than 300 feet with no outlet. The right-of-way diameter of a cul-de-sac shall be at least 110 feet. In order to provide adequate utility maintenance and storm drainage, an additional five-foot easement around the perimeter of cul-de-sacs may be required by the county engineer as deemed necessary.

d.

Pavement dimensions and materials:

i.

For subdivision streets: The minimum width of each travel lane shall have the minimum dimensions as specified in Table 6-03-02 per the functional classification defined in section 6.03.03. Curb or curb and gutter dimensions are not to be included in the specified lane widths.

Table 6-03-2
Minimum Lane Width —>	10'	11'	12'
Collector			X
Major Local		X
Minor Local	X

 

ii.

All other pavement dimension for widths, tapers, shoulders, clear zones, etc. shall be in accordance with F.D.O.T. Green Book Standards.

iii.

Cul-de-sacs:

1)

The pavement width for turnarounds shall comply with AASHTO latest edition ("A Policy on Geometric Design of Highways and Streets").

2)

The pavement diameter of a cul-de-sac shall be 100 feet.

e.

The surface course for flexible pavements will be an asphalt mix approved by the county engineer; thickness will be a minimum of one and one-half inches. Collectors, arterials, and other roads serving heavy traffic shall provide a structural analysis determining surface course thickness or have a minimum thickness of two inches whichever is greater. All cul-de-sacs will have a minimum surface thickness of two inches in the "turn around" area. Surface courses using materials other than asphalt will be sized for appropriate structural adequacy. Test for surface course thickness and density shall be made at intervals of no more than 200 feet; staggered to the left, right, and on center line.

f.

Curb and gutter: All streets constructed in residential subdivisions built to urban densities of four lots or more per acre shall have curb and gutter on both sides of the pavement. Swales within rights-of-way shall not be permitted where curb and gutter is required.

g.

Roadway base: An approved and properly prepared base material shall be provided. Recommended base materials are as follows: Sand-clay; soil cement; compacted limerock; shell. Tests for thickness and density shall be made at intervals of no more than 300 feet; staggered to the left, right, and on centerline.

h.

Structural analysis is required for roads arterial, collector and other identified by the county as supporting industrial land uses, such as but not limited to, industrial parks, airports, and landfills. The procedures set forth in AASHTO's A Guide for Design of Pavement Structures, the FDOT Flexible Pavement Design Manual, or the FDOT Rigid Pavement Design Manual shall be used. Base thickness for arterial or collector streets shall be a minimum of eight inches. Sand asphalt base shall demonstrate equivalency. Base thickness for all other streets shall be a minimum of six inches.

i.

Roadway subgrade: A properly prepared subgrade shall be provided with a minimum LBR of 40. Tests for subgrade bearing capacity and density shall be made at intervals of no more than 300 feet; staggered to the left, right, and on centerline.

j.

Material specifications and construction standards: All material and construction shall conform to the latest Florida DOT "Standard Specification for Road and Bridge Construction." If a Marshall mix design for asphalt pavement or a sand-clay base is used, the requirements in the Florida DOT Standard Specification for Road and Bridge Construction, 2000 Edition shall be used.

k.

Signage: All traffic control devices including street signs, stop signs and pavement markings shall be in conformance with the most recent addition of Manual of Uniform Traffic Control Devices.

l.

Datum: All plans shall be designed based on the NGVD 1929 or NAVD 1988. Benchmarks shall be provided per minimum technical standards.

m.

Roadway design plans: Plans submitted to the county engineer for review of roadway design shall include plan and profile sheets at a scale no smaller than one inch to 30 feet. All utility crossings and proposed piping shall be clearly depicted to show both horizontal and vertical locations.

(Ord. No. 11-01, § 2, 1-18-11)