§ 27-476. Street design standards.

(a)

Specifications. All construction shall conform to the current edition of "Standard Specifications for Road and Bridge Construction", published by Florida Department of Transportation.

(b)

Subgrade. The roadway shall be built upon stabilized subgrade at LBR40. Where the subgrade does not exceed a state bearing test of forty (40) pounds per square inch, a subgrade shall be stabilized to this strength.

(c)

Base construction. Base construction shall utilize only solid limerock, soil-cement, or sand bituminous road mix.

(d)

Surfacing. Surfacing shall consist of FDOT type S-I asphaltic concrete surface course with a finish surface course FDOT type S-III, crowned to a finish slope of one-fourth-inch per foot.

(e)

Dimensions. Minimum dimensions shall conform to the following table:

	Arterial	Collector	Local
Subgrade thickness (inches)	12	12	6
Pavement base thickness (inches)	8	6	6
Pavement thickness (inches) (S-I)	2.5	1.25	0
Surface course (inches) (S-III)	1	1	1.5
Pavement lane width (feet)	12/11*	12/11*	10

 

*Where a lack of space or obstacle imposes severe limitations.

(f)

Vertical curvature. Roadway curvature shall not be greater than five (5) percent, nor less than four-tenths (0.4) percent.

(g)

Street intersection angle. To the extent possible, streets should intersect at a perpendicular (ninety (90) degree) angle. Acute angles less than eighty-five (85) degrees or obtuse angles greater than ninety-five (95) degrees at street intersections shall be avoided. Where an acute or obtuse angle occurs between streets at their intersection, the alignment shall be curved so that tangents to the curves shall intersect as closely as feasible at right angles. Transition fillets at intersections shall be constructed, having a radius of at least fifty (50) feet. The right-of-way shall be curved to the same concentric radius.

(h)

Horizontal curvature. Where a deflection angle of more than ten (10) degrees in alignment of a street occurs, a curve of reasonably long radius shall be introduced. On all streets except local streets, the centerline radius curvature shall not be less than three hundred (300) feet; on local streets, the radius curvature shall not be less than one hundred (100) feet.

(i)

Street names. Street names shall be appropriate designations and not presently encountered in the county east of Pablo Creek. Street signposts readable from all approaches, eight (8) feet high, of corrosion-resistant materials, shall be constructed at each street intersection.

(j)

Culs-de-sac. Culs-de-sac shall conform to the following criteria:

(1)

Culs-de-sac shall not exceed six hundred (600) feet in length from the center of the turnaround to the nearest street intersection.

(2)

No culs-de-sac shall be permitted to be platted unless there are platted lots on each side and around the outer perimeter thereof.

(3)

Culs-de-sac shall be provided with a chord dimension at the building restriction line equal to or exceeding the minimum street frontage requirement.

(4)

Culs-de-sac shall have an unobstructed twelve-foot wide moving lane with a minimum outside turning radius of thirty-eight (38) feet. Upon a favorable determination by the city manager or designee, lands inscribed within a maximum inside turning radius of fourteen (14) feet may be retained as planted open space; in this case, the planted area shall be delineated with raised concrete curbing and shall provide for clear visibility between two (2) feet and eight (8) above the adjacent roadway centerline grade (see Figure 27-476-1).

Figure 27-476-1

(5)

Culs-de-sac greater than three hundred (300) feet in length shall include the posting of a "No Outlet" sign at the nearest street intersection.

(k)

Collector streets. At least one (1) end of all collector streets shall terminate on arterial streets.

(l)

Local streets. At least one (1) end of a local street shall terminate on a collector or higher order street. Local streets are generally discouraged from direct connections with arterial streets.

(1)

The City of Neptune Beach street ends terminating at the Atlantic Ocean and at the intracoastal waterway are special public rights-of-way which shall be carefully preserved for present and future public use.

(2)

Public walkways and ramps may be built in these rights-of-way. No other construction is permitted in these rights-of way except as necessary to access adjacent properties when no other means of access to said properties is possible.

(3)

In the event that access through a street end right-of-way is necessary, the design and construction of such access shall be approved or disapproved by the city council after appropriate development review. Criteria for approval shall include maximum preservation of greenspace within the street ends and the use of pervious paving materials.

(4)

In no case may access ways to adjacent properties be designed or landscaped in order to create the image of private property.

(m)

Alleys. Alleys shall conform to the following criteria:

(1)

Alleys shall be provided at the rear lot lines of all business and commercial subdivisions.

(2)

Alleys shall be prohibited in residential subdivisions, unless the developer designs the subdivision with alleys as an integral element of the project. Where alleys are utilized as an integral design feature, they shall provide for connections to no fewer than five (5) and no more than fifteen (15) residences per side, and shall terminate at both ends with a local street.

(n)

Environmentally sensitive areas. Streets shall be laid out to minimize negative impacts to environmentally sensitive areas, such as wetlands. In the event that impacts cannot be avoided, the developer shall meet all applicable requirements of local, state or federal permitting agencies.

(o)

Minimum stormwater management requirements. All roadway construction shall meet minimum stormwater management requirements of the appropriate local or state permitting agencies. At the discretion of the city manager or designee, roadways shall be constructed as open (swale) or closed (curb and gutter) typical sections.

(p)

Inter-neighborhood traffic flow. Streets in a new development shall be logically connected to rights-of-way in adjacent areas to allow for safe and efficient traffic flow between neighborhoods or subdivisions. If adjacent lands are unplatted, stub outs in the new development shall be provided for future connection to the adjacent unplatted land. Pedestrian and/or bikeway systems also shall be connected. To the extent that such pedestrian and bikeway connections may contribute to undesired increases in cut-through traffic then the community development board may recommend a withholding or modification to this requirement.

(q)

Through traffic. Residential streets shall be arranged or otherwise designed to discourage high speeds or excessive volumes of cut through traffic.

(r)

Offset intersections. Where an offset (jog) is necessary at an intersection, the distance between centerlines of the intersecting streets shall be no less than one hundred fifty (150) feet.

(s)

Street intersection spacing. No two (2) streets may intersect with any other street on the same side at a distance of less than four hundred (400) feet measured from centerline to centerline of the intersecting street. When the intersected street is an arterial, the distance between intersecting streets shall be no less than six hundred sixty (660) feet. New intersections along one (1) side of an existing street shall, where possible, coincide with existing intersections on the other side.

(t)

Deceleration and left and right turning lanes. Deceleration and left and right turning lanes shall be provided on collector or arterial streets according to the following guidelines, or as otherwise required by state department of transportation regulations. In addition, and based upon the submission of a traffic impact study acceptable to city, the city manager or designee may waive the requirements based upon a reasonable determination that the absence of such a lane will not adversely impact traffic conditions:

(1)

A right turn lane, with a minimum of fifty (50) feet of transition and one hundred (100) feet of storage, shall be provided at any project street or driveway entrance anticipated to generate more than sixty (60) right turns during any peak hour.

(2)

A left turn lane, with a minimum of twenty-five (25) feet of transition and one hundred twenty-five (125) feet of storage, shall be provided at any project street or driveway entrance anticipated to generate more than thirty (30) left turns during any peak hour.

(u)

Intersection visibility. In order to provide a clear view of intersecting streets to the motorist, nothing within the clear visibility triangle shall be erected, placed, parked, planted, or allowed to grow in such a manner as to materially impede vision between a height of two (2) feet and eight (8) feet above the grade, measured at the centerline of the intersection. The following shall be permitted within the clear visibility triangle:

(1)

Shade trees with trunks free of vegetation and limbs up to eight (8) feet in height from the grade;

(2)

Other landscaping, wall and earth mounds not exceeding a height of two (2) feet; and

(3)

Traffic and utility poles. The distance from the intersection of the street centerlines for the various road classifications shall be as follows for clear visibility triangles:

Accessway intersecting an Accessway	6 feet
Accessway intersecting a ROW	10 feet
ROW intersecting a ROW	35 feet

 

(v)

Signage, pavement markings and signalization. The developer shall provide all necessary roadway signs, pavement markings and traffic signalization as may be required by the city, based upon the guidelines in the Manual of Uniform Traffic Control Devices, or alternative city standards as approved by the community development board. At least two (2) street name signs shall be placed at each four-way street intersection, and one (1) at each "T" intersection. Signs shall be installed under light standards and free of visual obstruction. The design of street name signs shall be consistent, of a style appropriate to the community, and of a uniform size and color.

(w)

Blocks.

(1)

Where a tract of land is bounded by streets forming a block, said block shall have sufficient width to provide for two (2) tiers of lots of appropriate depths.

(2)

The lengths, widths and shapes of blocks shall be consistent with adjacent areas. In no case shall block lengths in residential areas exceed eight hundred (800) feet, nor be less than four hundred (400) feet in length.

(Ord. No. 2004-10, § 1, 10-4-04; Ord. No. 2005-06, § 2, 5-2-05; Ord. No. 2010-14, § 46, 9-7-10; Ord. No. 2013-09, § 1, 10-7-13)