[Amended 7-10-1979; 9-9-1987; 6-8-1988; 3-8-1995 by L.L. No.
3-1995]
A.
B.
Street design (also see § 88-28 for guideline construction specifications).
(1)
The arrangement, character, extent, width, grade and location of
all streets shall be considered in their relation to other existing
and planned streets, to topographical conditions, to public convenience
and safety and in their appropriate relation to the proposed uses
of land to be served and/or abutted by such streets.
(2)
Streets in a subdivision shall:
(a)
Provide for the continuation or appropriate projection of existing
streets in the surrounding area; or
(b)
Conform to a plan for the neighborhood approved or adopted by
the Planning Board to meet a particular situation where topographical
or other conditions make continuance of or conformance with existing
streets impracticable.
(3)
Minor streets shall be so laid out that their use by through traffic
will be discouraged.
(4)
Where a subdivision borders on or contains a railroad right-of-way,
the Planning Board may require a street approximately parallel to
and on each side of such right-of-way at a distance suitable for the
appropriate use of the intervening land, as for park purposes in appropriate
districts. Such distances shall also be determined with due regard
for the requirements of approach grades and future grade separations.
(5)
Reserve strips controlling access to streets, water plants or sewage
treatment plants or to other land dedicated or to be dedicated to
public use shall be prohibited except where their control is definitely
placed in the Town under conditions approved by the Planning Board.
(6)
Half streets shall be prohibited except where essential to the reasonable
development of the subdivision in conformity with the other requirements
of this chapter. In cases where the Planning Board finds it will be
practicable to require the dedication of the other half when the adjoining
property is submitted, the other half of the street shall be platted
within such tract.
(7)
Dead-end streets, designated to be so permanently, shall not be longer
than 500 feet in general and no longer than 600 feet in any case and
shall be provided at the closed end with hammer heads of 30 feet by
30 feet for each extension.
(8)
Block lengths shall not exceed 1,200 feet nor be less than 400 feet.
Block widths shall not be less than twice the minimum lot depth. Where
the block minimum length does not apply, the minimum center-line distance
between intersections shall be 150 feet.
(9)
All local streets, as defined by AASHTO definition and so designated
by the Planning Board, shall have a minimum right-of-way width of
50 feet. The drive strip of said minor streets shall have a minimum
pavement width of 24 feet.
[Amended 4-11-2007 by L.L. No. 3-2007]
(10)
All collector streets, as defined by AASHTO definition and so
designated by the Planning Board, shall have a minimum right-of-way
width of 50 feet. The drive strip of said minor streets shall have
a minimum pavement width of 24 feet.
[Amended 4-11-2007 by L.L. No. 3-2007]
(11)
All streets designated by the Planning Board as arterial streets
shall have a minimum right-of-way width and a minimum drive strip
width as specified by the Planning Board, in consultation with the
Highway Superintendent and Town Board Highway Committee, after a thorough
study of the potential future use, traffic volume and area development
has been made.
[Amended 4-11-2007 by L.L. No. 3-2007]
(12)
In sections of any proposed street or road where physical conditions
necessitate the construction of excavation or embankments (cuts or
fills), grade backslopes, ditches, drainage structures, bridges or
other street- or road-related structures, and where these structures
combine to form a total construction width greater than the standard
50 feet of right-of-way, then the right-of-way shall be of sufficient
width to include said structures through those sections of the proposed
street or road. All necessary or required easements from abutting
property owners must also be arranged for and conveyed at no additional
expense to the town (see Drawing Nos. 1A and 1B).[2]
[2]
Editor's Note: Said drawings are included at the end of this
chapter.
(13)
Special treatment along arterial streets. When a subdivision
abuts or contains an existing or proposed arterial street, the Planning
Board may require marginal access streets, reverse frontage with screen
planting contained in a nonaccess reservation along the rear property
line, deep lots with rear-service alleys or such other treatment as
may be necessary for adequate protection of residential properties
and to afford separation of through and local traffic.
(14)
Pedestrian circulation. Pedestrian crosswalks with a right-of-way
of not less than 10 feet wide shall be required where deemed essential
to provide circulation or access to schools, playgrounds and other
community facilities.
(15)
Horizontal alignment.
(a)
Street and/or road right-of-way boundaries at street intersections
shall be rounded with a radius of 10 feet or with a greater radius
where the Planning Board may deem necessary. The Planning Board may
permit comparable cutoffs or chords in place of rounded corners.
(b)
Curb radii at intersections of local streets or roads shall
not be less than 20 feet.
(c)
Curb radii at the intersection of any local streets or roads
with a collector street or road shall be a minimum of 40 feet.
(d)
Street jogs with center-line offsets of less than 125 feet shall
be avoided.
(f)
The minimum design speed for design of horizontal curves shall
be 30 miles per hour.
(g)
For horizontal curves where no superelevation is provided, the
maximum permissible degree of curve along any section of road shall
be 15° [and minimum radius equals 382 feet]. The degree of curve
is defined as the central angle subtended by a one-hundred-foot length
of curve, along the arc.
|
Degree of curve =
|
5,729.5779
Radius of curve
|
(h)
For horizontal curves where superelevation is provided, maximum
permissible superelevation shall be 0.08 foot per foot.
(i)
For horizontal curve where superelevation is provided, the plans
shall show the derivation, coefficient of friction and degree of curve.
[1]
The following AASHTO limits for coefficients of side friction
apply:
|
Design speed (mph)
|
20
|
30
|
40
|
50
|
60
|
|
Maximum coefficient of side friction
|
0.17
|
0.16
|
0.15
|
0.14
|
0.13
|
[2]
The following is a relationship between maximum permissible
degree of curve (Dmax), design speed in miles per hour (velocity,
V), design maximum superelevation in feet per foot (e) and design
maximum coefficient of fraction (f):
|
Dmax =
|
85,950 (e + f)
V2
|
[3]
Note from the above that the absolute maximum degree of curve
allowed in the Town of Oneonta with full maximum superelevation [0.08
foot per foot] is 23° [and minimum radius equals 249 feet]. The
designer is urged to plan his roads such that curves will be as gradual
as possible, far under this extreme limit, as far as practical given
site conditions.
(j)
Where severe site constraints make it impossible to design for
a speed of 30 miles per hour, the Planning Board may consider allowing
design speeds as low as 20 miles per hour, conditional on provision
for traffic control (i.e., speed limit posting signs, speed control
bumps or other devices).
(16)
Vertical alignment.
(a)
The minimum center-line grade shall be 1/2 of 1%.
(b)
The maximum center-line grade shall be 8% for collector streets
and 10% for local streets. Where severe site constraints make it impossible
to maintain the center-line grades stated above, the Planning Board,
in consultation with the Highway Superintendent, may consider allowing
center-line grades up to 15%.
(c)
At the intersection between a local and a collector street,
the maximum center-line grade of either street shall be 3% within
100 feet of the intersection.
(d)
All changes in grades of more than 1% shall be connected by
a vertical curve which shall have a minimum length of 100 feet.
(17)
Sight distances shall be established by applying New York State
Department of Transportation standards.
(18)
Standards for all highways shall be established by the Planning
Board with the advice from the Highway Superintendent, Public Works
Department or Town Engineer.
(19)
Pavement crown (see Drawing Nos. 1A, Typical Street Section,
and 1B, Typical Road Section, at the end of this chapter).
(a)
Streets and roads shall be crowned to prevent water and ice
from accumulating on the pavement surface. The normal crown shall
be 1/4 inch per foot for the travel lanes and 3/4 inch per foot for
shoulders.
(b)
Where curves are superelevated, the maximum algebraic difference
between the travel lane and the shoulder cross slopes shall be 0.08
foot per foot.
(20)
Curb and gutter (see Drawing Nos. 1A, Typical Street Section,
1B, Typical Road Section, and 2, Typical Curb Section, at the end
of this chapter). Integral curb and gutter shall be required on all
streets of residential subdivisions having a lot size of less than
one acre. Where the subdivider proposes, and the Planning Board approves,
sections of subdivisions where all lots are above one acre, the Planning
Board may, with the agreement of the Town Highway Superintendent,
waive the requirement for integral curbs and gutters.
(21)
Cross drains. Cross drain culverts shall be placed a minimum
of 18 inches below the street's finished grade.
