A.
It is the purpose of this article to implement the provisions of § 125-29G, Type 5 lots, and § 125-34, Mini-subdivisions, added to the Harvard Protective Bylaw in March 1981. A mini-subdivision is a subdivision made in accordance with a special permit granted by the Planning Board under § 125-34, Mini-subdivisions, of the Harvard Protective Bylaw, in which up to three lots may have frontage on a way designed to well-constructed driveway standards. The Protective Bylaw also provides conditions under which this way may also serve a fourth lot whose frontage is on a regular street.
B.
The Protective Bylaw sets up a number of conditions on the use of
mini-subdivisions. Among these are:
(1)
Mini-subdivisions are available only for residential use.
(2)
Each lot which has frontage on the mini-subdivision way must meet
the Bylaw standards for Type 5 lots which included, in 1981, a frontage
of 180 feet and a minimum land area of three acres.
(3)
The way serving the mini-subdivision is not to be extended and must
be permanently restricted to being private property.
(4)
The Planning Board must grant a special permit for the mini-subdivision.
(The hearing for the special permit is held concurrently with the
hearing on the definitive plan for the mini-subdivision.)
C.
It is the intent to provide for light-duty roadway construction and
street design for situations in which there is no through passage
or linkage with other ways or driveways, in which design for twenty-mile-per-hour
traffic movement is adequate, in which the number of house lots being
served does not exceed four, and in which the total frontage required
of these lots is generally less than the length of both sides of the
roadway that will serve them. Thus, not only are light (driveway)
construction standards permissible, but drainage can be provided on
the assumption that not every foot of street side line will be potential
frontage.
As used in this article, terms shall have following meanings
except where the context indicates otherwise:
The roadway of the mini-subdivision. The terms "drive" and
"way" for the mini-subdivision correspond to the terms "roadway" and
"street" as used in the Protective Bylaw and in describing a conventional
subdivision.
A branch driveway serving an individual lot. Shared driveways
are not permitted in mini-subdivisions.
The roadway of a regular street (see below).
A public way or an approved subdivision way not constructed
under this article.
The entire Article V, Mini-Subdivision, of this chapter.
The right-of-way of the mini-subdivision, corresponding to
the street of a usual subdivision.
Generally, all provisions of this chapter apply to mini-subdivisions
except as they are specifically modified here.
A.
Mini-subdivision as variation. Wherever the provisions of this article modify the provisions of other sections, the provisions of this article shall be interpreted as variations of provisions of such other sections of this chapter. Such variations shall be valid only if they are found to be in the public interest as a result of the special permit proceeding for the mini-subdivision. (See § 130-5 of this chapter.) In any instance in which the Planning Board has reason to believe that such other provisions should not be varied, either in whole or in part, it shall apply the suitable stricter standards found elsewhere in this chapter, unvaried. In particular, such stricter standards shall be considered:
B.
Applicability of flexible plan subdivision.
(1)
Mini-subdivision may be combined with residential use FPS (flexible
plan subdivision) as provided in the FPS development and single residence
use sections of the Protective Bylaw.[1] Under FPS, individual conventional Type 5 lot dimensions
may be reduced to those given in the following table:
|
Minimum Reduced Dimensions
for Type 5 Lots under FPS
|
|
Item
|
Reduced Size 1981 Bylaw
|
1982 Bylaw Change
|
|---|---|---|
|
Minimum land area (acres)
|
> 2
|
> 2
|
|
Lot width circle diameter (feet)
|
288
|
270
|
|
Lot width circle setback from center line of way (feet)
|
170
|
155 to 180
|
|
Minimum compact contiguous area of buildable land (acres)
|
> 1/2
|
> 1/2
|
|
(Note: A Protective Bylaw amendment passed by the 1982 Annual
Town Meeting reduced the applicable FPS lot width circle diameter
to 270 feet at a setback of 155 feet, as well as relaxing common open
space requirements under FPS.)
|
(2)
Interpretation of lot width circle location. The FPS development
section of the Protective Bylaw provides that this chapter may provide
interpretive detail for the overall design of an FPS. To achieve maximum
flexibility in combining FPS with mini-subdivision, the center of
the lot width circle may be located anywhere between the reduced and
the unreduced setback distance from the center line of the way (see
table above). (This interpretation was explicit in the 1982 Bylaw
change proposal.)
C.
Mini-subdivisions on dead-end streets. A conventional dead-end street which is longer than 500 feet shall end in an approved turnaround as in Article IV. A conventional dead-end street which is less than 500 feet long may end in an approved turnaround of the type specified in Article IV. Alternatively, it may branch at its end into two mini-subdivision ways at a "T" ("Y") intersection, as specified in this article, but both methods shall not be used together. Otherwise, the intersection of a mini-subdivision way with a conventional dead-end street shall be at least 270 feet from the beginning of the turnaround at the end of such street and at least 270 feet from the street on which the dead end begins.
(1)
Permanently private limited-use dead-end street. If a conventional
dead-end street ends in a branch into two mini-subdivision ways and
the street, including connected mini-subdivisions, serves only single-
or two-family dwellings not exceeding a total of eight dwelling units,
and there is no planned or actual commercial activity served, including
commercial agriculture, and the subdivision for the street is joined
to the mini-subdivision in such a manner that the street is included
in the restrictions, to run with the land, that such street is to
remain permanently private property managed and maintained by the
qualified homeowners' association and that such street may not be
extended, then:
(2)
Terminal "T" design. If a dead-end street ends in two mini-subdivision
ways, it shall do so in a "T" ("Y") intersection such that:
(a)
No pair of center lines of the legs of such "T" ("Y") project
to meet at an angle of less than 90° or more than 180°; and
(b)
The intersection is usable as a turnaround (backing up only
once) by an AASHO SU30 single-unit truck and by an AASHO C50 trailer
truck; and
(c)
The sides of the intersection at the end of the street have
an (additional) easement for the disposal of snow from snowplowing
the intersection.
Subsections A through C of this section are policy statements
by the Planning Board which may be cited in connection with a particular
substantive finding or judgment by the Board.
A.
Mini-subdivision as an alternative to hammerhead or backland lots.
It is intended that mini-subdivision serve as an alternate means of
development for land that might formerly have been developed as a
constellation of hammerhead and/or backland lots served by common
or shared driveway(s). A series of access necks for such lots side
by side poses a potential public safety hazard sui generis because
they include the right (and the feasibility) to build individual driveways.
The individual driveways, if built, are generally too close together
for safe traffic flow on the winding and hilliest parts of the old
roads that make up most of the preexisting street frontage in Harvard.
In addition, a collection of driveways leading to houses generally
not visible from the street poses a major source of confusion and
hazard in time of fire, police, or ambulance emergency, not only for
the victims but for the personnel attempting to provide the emergency
services.
B.
Shared driveways as possible creators of subdivisions. In the past,
before mini-subdivision became available, many groups of lots have
been served by a shared driveway with no intention, and marginal economic
feasibility, of developing individual lot accesses to the street.
It is possible that such lots do not have the access to public services,
and to the street, contemplated by the Subdivision Control Law, even
though some control over adequacy of layout and construction of the
driveway is available through Bylaw specifications and special permit
restrictions.
(1)
The fact that a developer never intends that access be over other
than a common or shared driveway may be an indication that he is building
a subdivision within the meaning of the SCL. In Gifford et al vs.
Planning Board of Nantucket et al (Mass 383 NE 2d 1123), the State
Supreme Judicial Court considered a division of land into many hammerhead-type
lots to be a subdivision, even though the lots had nominal frontage
on a public way, and even though the plan had been endorsed by the
Planning Board as not requiring approval under the SCL. The Court,
in its decision, laid emphasis upon the length of access necks, inadequacy
of lines of sight to traffic from some frontage, confusion of driveways
and unobservability of houses from the street for adequate fire protection
and police patrols. Finally, the Court noted that there was no real
intent to use the individual necks as access: "...the measure of the
case was...that the developers would ultimately have to join some
necks to provide ways from lots to the public way; but that is an
indication that we have here a subdivision requiring antecedent approval."
(2)
Any way or driveway which provides access to the street for two or
more lots may be providing de facto (but not legal) frontage for those
lots; if used as a street, such a way should be designed as a street
providing legal frontage, with design appropriate to the expected
intensity of use, whether or not buildings could have been served
from some other street.
(3)
The fact that the Protective Bylaw may provide specific minimum geometric
design standards for certain types of driveways or ways does not relieve
the Planning Board of its responsibilities under the SCL to require
access to lots over ways that meet minimum construction standards
also.
C.
Shared driveway construction policy. It will be the policy of the
Planning Board to require the same standards of construction for shared
driveways under a special permit for hammerhead and/or backland lots
as it requires for the corresponding light use of a mini-subdivision
drive under this chapter.
All of the provisions of Article III, Subdivision Plans and Procedures, apply to mini-subdivisions without variation, except as specifically provided below.
C.
Definitive plan. Provisions of § 130-17, Definitive plan, remain unvaried except:
(1)
Contours and incidental features. Detailed contouring is required
only in the general vicinity (e.g., within 75 feet) of the proposed
drive and its drainage system, or other areas where land is to be
graded or filled, and the site plan may omit features, such as some
stone walls, which are unrelated to the way, to lot boundaries, or
to the siting of structures.
(2)
Name. Each mini-subdivision way will be assigned a name by the Planning
Board in accordance with its then-current policy. Suggested names
will be given consideration but not necessarily adopted. Any sign
bearing the street name shall also include the designation "Private
Property."
(3)
Restrictions. The plot plan shall identify as such all land that is to be held and administered by a qualified homeowners' association. It shall bear restrictions satisfactory to the Planning Board, to run with the land, permanently restricting the way(s) shown to remain private property and not to be extended, and any other restrictions and easements that are required for the mini-subdivision by this chapter and by the Protective Bylaw. It shall incorporate by reference the documents, satisfactory to the Planning Board, creating the qualified homeowners' association and setting forth permanent responsibility for the common open space and for maintenance and snow removal on the mini-subdivision way(s). Said documents shall be recorded after the approval of the plan and prior to its endorsement. (For process and requirements for the creation of common open space and the qualified homeowners' association, see § 130-37.)
D.
Performance assurance. The provisions of § 130-19, Performance assurance, remain unvaried except:
(1)
Reduction of security for performance assurance. At his option the developer may execute one of the forms of completion security, to the full amount of the cost plus inflation and overhead, as set forth in § 81U of the SCL and Article III of this chapter. Alternatively he may elect to provide reduced completion security in accordance with all of the terms of this subsection.
(a)
The developer may provide as security for the completion of the mini-subdivision (but not associated regular subdivisions) a cash deposit in an amount equal to the cost to the Town, plus inflation and overhead, as specified in Article III of this chapter, of obtaining as-built plans, placing bounds, and installing street signs. However, all of the following conditions must be met:
[1]
The Planning Board must have inscribed on the definitive plot
plan conditions in accordance with SCL § 81R that no building
permit will be issued on any particular lot until the Planning Board
has stated in writing that a stable and usable drive has been constructed
and installed to serve that lot, conforming in geometric layout and
in construction to that specified in the site and profiles plans approved
by the Board, and that utilities have been provided and any required
measures for fire protection have been completed; and
[2]
The amount of the deposit must be satisfactory to the Planning
Board; and
(b)
The rationale of this reduction in security is that in such
cases, where the way and the drive are not adequate for general subdivision
use, the imposition of conditions under SCL § 81R is proper,
and since there is no possibility of change of use or intensity of
use by extension, the public interest and responsibility are adequately
served by such conditions.
(2)
Completion. Reduction of security shall not affect the procedures
or criteria for judging completeness of the way as a street under
this chapter nor the applicability of § 81U of the SCL.
Until the way is complete (after a winter and succeeding spring),
the drive will be inspected, or reinspected, for adequacy prior to
each and every authorization for a building permit and prior to the
issuance of each and every occupancy permit. (The intended effect
of the reduction of security and the use of conditions under § 81R
is to permit construction to proceed in a mini-subdivision just as
it would for a collection of hammerhead and backland lots served by
a shared driveway, without necessarily having to wait for the passage
of a winter and succeeding spring, even though the judgment of final
completion is so postponed.)
All of the provisions of Article IV, Design and Construction Standards, of this chapter shall remain unvaried except as specifically varied below. Variations within a subsection or sentence extend only to the subject matter of the variation and not to related matters or other matters in the same subsection or sentence.
A.
Number of lanes. On that part of the way which serves as frontage
for two or more lots, or for which the drive serves two or more lots,
the drive shall be two lanes wide. That part of the drive which serves
only one lot may be one lane wide, provided it widens to two lanes
for passing at least every 300 feet. A single-lane drive shall also
widen to two lanes for a distance of at least 25 feet, plus flare
and transition {see Subsection D(3)(c)[7][c], Transition, below},
at the intersection with the roadway of a street.
B.
Alternate specification of widths. As an alternative to the specification
of width of drive and the computation of width of gravel base and
shoulders in the subsections below, the width dimensions tabulated
in Table A may be substituted for the width computations in the referenced
subsections of this section, subject to the conditions noted in the
table, and subject to the limitations below.
(1)
Table A may not be used for segments of the drive for which cut or
fill exceeds three feet, nor in turnarounds and intersections where
the inside radius of the finished surface of the drive is less than
70 feet. The information provided in Table A in the columns marked
"Conventional Subdivision" and "Limited Use Private Dead End" is for
comparison purposes only and is not for use in design. Table A does
not replace or supersede the mini-subdivision width requirements of
any numbered subsection other than the ones referenced for each specific
case in the "See Sections" column.
(2)
When Table A is being used in width design, the finished surface
of the drive should be located on the gravel base in such a way that
the base extends into or under both shoulders by at least two feet.
The placement of the drive surface on curves should be asymmetric,
where this is possible within the foregoing constraint, so that there
is two feet more gravel width under the shoulder on the inside of
the curve than on the outside.
(3)
Note that Table A does not permit a reduction in width of roadway
plus shoulders below 20 feet, because it is assumed that the single-lane
drive is nevertheless a fire lane within the intent of the National
Fire Prevention Code (NFPA Standard 1, Section 3.1.1.10), which requires
20 feet of fire lane width to all buildings set back more than 150
feet from the public road. When the provisions of this section are
being used as guidelines for the specification of a driveway (not
a mini-subdivision drive) less than 150 feet long, then sixteen-foot
width of roadway plus shoulders may be used. The Planning Board urges
that all driveways over 150 feet long be cleared to the full twenty-foot
fire lane width.
|
Table A
Street and Roadway Width Requirements
|
|
Item
|
See §§ 130-
|
Conventional Subdivision (Including Standard Dead End)
|
Limited Use Private Dead End [See § 130- 30C(1)]
|
Mini- Subdivision
|
|---|---|---|---|---|
|
Width of right- of-way (feet)
|
23D(1)(a) 33D(3)(c)[1]
|
50
|
40
|
40
|
|
Width of roadway plus shoulders (feet)
|
30C(1) 33D(3)(c)[7][a] and [b] 33D(5)(a)[2] 33F(2)
|
> 36 to 38
|
> 32
|
Two lanes: > 241 One lane: > 20
|
|
Width of gravel base (feet)
|
23D(1)(g) 23F 30C(1) 33D(3)(c)[7][a] and [b] 33D(5)(a)(2) 33F(3)(a)
and (b)
|
28 to 32
|
> 24 to 26
|
Two lanes: > 241 One lane: > 202
|
|
Width of finished surface (feet)
|
33D(3)(c)[7][a] and [b]
|
24 to 26 Paved
|
> 20 Paved
|
Two lanes: > 183,4 One lane: > 12
|
|
NOTES:
|
|
1If the condition below is met, this
distance may be reduced to 20 feet.
|
|
2If the condition below is met and
the distance to the nearest house is more than 200 feet so that, in
the opinion of the Planning Board, provision for drive-side parking
is not necessary, this distance may be reduced to 16 feet.
|
|
3If the condition below is met, the
width may be reduced to 16 feet.
|
|
4See § 130-33F(2) for surfacing options.
|
|
Condition for reduced width: In the judgment of the Planning
Board, the drive is nearly straight (center-line radius of curvature
greater than 200 feet) and is essentially at grade on a firm subbase
and the distance along the drive to the nearest intersection, driveway
or turnaround, or to the street, is more than 40 feet.
|
C.
Open space. Mandatory open space areas to be held in common shall
include the subdivision way and any islands within turnarounds.
D.
Way design. Design of the way shall be in accordance with § 130-23, Street design, except:
(1)
Projection of way prohibited. Ways shall not be designed for projection
to other streets nor for access to other streets or property (other
than open space or conservation areas) not in the mini-subdivision.
A mini-subdivision shall not be used as the extension of a dead-end
street, or connected to a dead-end street, except as specifically
provided above in this section.
(2)
Intersection angle with street or driveway. Intersection angles between the mini-subdivision way and a street or between the mini-subdivision way and a connecting driveway shall be as in § 130-23C, Intersections.
(3)
Dimensions. Way and drive construction shall be for twenty-mile-per-hour
light traffic on rolling terrain in accordance with AASHO Design Guide
for Local Roads and Streets, Part I, Rural (1971 Revision of 1970
Edition, abbreviated hereafter "AASHO DG"), Tables 2, 3, 4, 5, 6,
7 and 10, except that design grade is not to exceed 10% except with
permission from the Planning Board.
(a)
If there is clear visibility across the inside of the curve
with vegetation full leaf, and if the grade in the curve does not
exceed 6%, fifteen-mile-per-hour design, one-hundred-foot sight distance,
and eighty-foot center-line radius of curvature may be used for curves
whose center-line radius is between 80 and 125 feet.
(b)
The following table tabulates some provisions of Tables 2, 4
and 10 of the AASHO DG and of this chapter with respect to radius
of curves. The table is for comparison purposes only and does not
waive any requirements of this chapter.
|
Sight Lines and Curves for Mini-Subdivision Drive
| |||
|
Sight Distances
| |||
|
Stopping sight distance (AASHO DG Table 2)
|
150 feet
| ||
|
Visibility at intersection of drive with street (AASHO DG Table
10):
| |||
|
Streets with through traffic (See footnote, Table of Clear Lines
of Sight)
|
400 feet
| ||
|
Streets with local traffic only (See footnote, Table of Clear
Lines of Sight)
|
300 feet
| ||
|
Dead-end streets less than 500 feet long
|
200 feet
| ||
|
Horizontal Curves (based on this chapter
and AASHO DG Table 4)
| |||
|
Minimum center-line radius of curvature for:
| |||
|
Drive outside turnarounds with clear line of sight across inside
of curve with terrain in full leaf, and where the grade in the turn
is < 6%
|
80 feet
| ||
|
Use of drive with frontage in loop turnarounds
|
80 feet
| ||
|
Elsewhere outside turnarounds and where grade exceeds 6%
|
100 feet
| ||
|
In parts of loop turnarounds not used as frontage (minimum outside
radius of drive)
|
50 feet
| ||
(c)
Mini-subdivision way and drive shall conform to the following:
[1]
Way width > 40 feet.
[2]
Linear dimensions in Figure 1[1] are reduced from 50 feet and 75 feet to 40 feet and 60
feet, respectively.
[1]
Editor's Note: Figure 1 is included at the end of this chapter.
[3]
Except in turnarounds, center-line radius of curvature shall
be not less than 80 feet. The radius may be as little as 80 feet where
the grade does not exceed 6% and where minimum sight distance for
speed exists across the inside of the curve. Otherwise, center-line
radius of curvature shall conform to Table 2 of AASHO DG for 20 miles
per hour and superelevation up to and including 10%. (AASHO DG Table
2 curve radius may be rounded off to the nearest multiple of 25 feet.)
[4]
Stopping sight distance as in AASHO DG Table 10. Such distance
is less than that in the second row of the Table of Clear Lines of
Sight of this chapter because it is not necessary to allow for use
of the mini-subdivision drive by school buses.
[5]
No tangents needed separating reverse curves if sight distance
is maintained.
[6]
Separation of intersections. The general objective for separating
mini-subdivision ways from one another, from common driveways, and
from parallel streets is to avoid single minimum-size residential
lots having multiply used ways on three sides and to avoid confusing
multiple entrances to backland. Separation shall be as follows:
[a]
Intersections of driveways with the mini-subdivision
way shall be not closer than 50 feet to the street, and there shall
be sufficient separation along the drive between such intersections
that snow removal from adjacent driveway intersections does not conflict.
[b]
Common driveways and the mini-subdivision way shall
have at least two-hundred-fifty-foot separation of center lines, except
where the Planning Board finds closer spacing at the street, or elsewhere,
to be of no detriment in the safe, convenient use of the intervening
land.
[c]
Separation of mini-subdivision ways on the same
side of the street shall be at least 180 feet plus 30 feet for each
lot served by the way.
[7]
Width of drive. (Note: The Protective Bylaw limits the center-line
radius of curvature outside turnarounds and intersections.)
[a]
On single-lane sections, > 12 feet, widening on curves to W feet where W is given by the formula:
W > 10 + 200/R, for R less than 100 feet, where
R is the inside radius of the drive in feet.
[b]
On two-lane and passing sections, > 16 feet, widening on curves to W feet where W is given by the formula:
W > 15 + 225/R, for R less than 225 feet, where
R is the inside radius of the drive in feet.
[c]
Transition. The length of transition between sections
of drive having different widths shall be > eight feet of length per one foot of width change.
[d]
Intersections with driveways shall be two lanes
wide, 35 feet on either side of intersection of center lines, plus
transition.
[e]
Where both sides of the drive lie in cut or on
fill, the above width dimensions shall be increased by two feet.
[8]
No change in minimum edge radius (> 25
feet).
[9]
Center-line grades: > 1% (to prevent
undrained depressions); < 10% (< 6% in turnarounds); consistent with AASHO DG on
curves; < 3% within 35 feet of a street
intersection; < 7% within 100 feet of a
street intersection.
(4)
Turnaround. The mini-subdivision way is a dead-end street which shall
terminate in a turnaround. It shall not branch into further ways or
streets. The turnaround may be designed as a single-lane loop (with
the entire interior of the loop being part of the way) or as a "T"
("Y") turnaround where both branches of the "T" ("Y") crossbar continue
as driveways. The objective of these requirements is to ensure the
maximum chance that the turnaround will be kept open by routine snowplowing
in winter. The outside arc of a loop turnaround may be used for lot
frontage, provided the arc radius is not less than 80 feet. The diameter
of a loop turnaround shall not exceed 240 feet, but otherwise Figure
2[2] applies to this section only as a guide to design.
(a)
The mini-subdivision way may extend 700 feet from the side line
of a street, or from a fire pond or other approved source of water
for fire fighting, the measurement being the most direct within the
way to the far side of the turnaround.
(b)
Junctions of driveways with the mini-subdivision drive shall
be designed and constructed to be usable as turnarounds by an AASHO
SU30 single-unit truck, and if the drive terminates on a street designated
as serving through traffic in the Table of Clear Lines of Sight, the
driveway junction closest to the street shall be usable as a turnaround
for an AASHO C50 trailer truck.
(c)
Lots may not have frontage on the end of the way unless it widens
to the dimensions and design of a loop turnaround.
(d)
Loop drive design shall be adequate for an AASHO C50 trailer
truck use, moving forward. The outside radius of curvature of the
loop drive shall not be less than 50 feet. The center of the turnaround,
whether or not improved, shall be part of the mini-subdivision way.
The way shall extend radially at least seven feet beyond the outer
edge of the finished surface of the drive.
[2]
Editor's Note: Figure 2 is included at the end of this chapter.
(5)
Shoulders. Shoulders shall be > two feet wide
on both sides of a two-lane drive. On single-lane sections, one shoulder
should be > five feet wide to allow for parking
without interfering with access. Shoulder slope profiles may be adjusted
to cause unconcentrated runoff to sheet off the way, but concentrated
runoff may not cross unprotected shoulders.
(a)
On curves and embankments shoulders shall widen as follows:
[1]
Shoulders less than five feet wide shall widen by two feet for
each vertical foot of embankment beyond the first three feet above
natural grade.
[2]
An outside shoulder on curves shall have a width of at least
S feet where S is given by the formula: S = 2 + 150/R, where R is
the inside radius of the drive in feet.
(b)
A shoulder abutting a cut shall be increased in width by two
feet over the width specified above (in order to have adequate room
for plowed snow).
(6)
Underground utilities. Underground utilities may be required in open
areas and in harmony with the neighborhood. Poles and lighting standards
(if used) shall be at least five feet from the edge of the drive.
(7)
Drainage design. Drainage design requirements are not varied, except
that the use of catch basins and storm sewer lines is to be based
on need as determined by the Planning Board rather than to be universally
compulsory. Need for catch basins can be assumed at the intersection
of the way with a street if the Selectmen do not determine otherwise
and elsewhere where, in the opinion of the Planning Board, there is
concentration of runoff from a sufficiently extensive area to result
in erosion if catch basins are not used.
(8)
Footpaths. Footpaths need not be provided except as access to open
space of conservation areas where, in the opinion of the Planning
Board, the nature of the terrain makes access otherwise difficult.
(9)
Curbing. Curbing may be required where the drive is paved and where
there is concentration of runoff.
(10)
Drive-side trees. With occasional exceptions, trees shall be
far enough back from the drive to permit drive-side parking without
blocking the traveled drive.
(11)
Street sign location. No change in street sign location. [See however § 130-32C(2), Name, above, and Subsection F(5) below.]
(12)
Bounds. No change in bounds for the way.
E.
Other improvements. All of the provisions of § 130-24, Other improvements, shall apply, except that in an isolated mini-subdivision not having a suitable water supply as part of the locus (including land that was held or controlled in common with the proposed mini-subdivision or after on December 31, 1981), a fire pond or cistern will not be required. However, if the mini-subdivision is being developed along with other properties encompassing 10 or more lots or covering 25 or more acres, then the fire pond or cistern may be required. In determining the need for a fire pond or cistern, or other means of supplying water for fire fighting, the Board may take into consideration the results (including preliminary results) of the deliberations of the Fire Pond Site Selection Committee established by the 1981 Annual Town Meeting.
F.
Construction details. Construction shall be as in § 130-25, Construction details, except as specifically varied below.
(1)
Crown. The drive shall have a four-inch crown or, if approved by
the Planning Board, a cross slope of 1/4 inch to 1/2 inch per foot
(AASHO DG Table 3).
(2)
Drive surface. The drive surface may have a gravel finish if its slope is between the permitted minimum and 5%, inclusive, except where it is the opinion of the Planning Board that the terrain and design result in water being carried along the drive surface (rather than sheeting off at right angles to it), in which case the surface shall be sealed or paved as the Board requires. The drive may have a sealed surface for grades up to 8% inclusive, except where soil and potential erosion conditions are such that it is the opinion of the Board that a heavier-wear surface is needed. Grades over 8%, and others as required by the Board, shall be paved as specified for conventional subdivision (§ 130-25A).
(a)
Gravel finish shall be at least three inches thick, compacted
measure. It shall be of a composition suitable, in the opinion of
the Planning Board, for the actual drainage conditions and shall contain
no stones larger than 1 1/2 inches in size. Where the subbase
is firm, well-drained gravel, the Planning Board may permit the substitution
of a four-inch layer of finish gravel for the upper four inches of
gravel base (the total gravel thickness remaining at least 12 inches).
(b)
A drive surface that is to be sealed shall have a base and finish as required for an unsealed drive. It shall then be sealed by penetration with at least one gallon per square yard of an asphalt emulsion or cut satisfactory to the Planning Board, with conditions of application as specified for asphalt penetration in § 130-25A, Roadway subgrade, base and surface.
(3)
Gravel base. The gravel base shall be constructed as specified for conventional subdivision roads (§ 130-25A), except that the depth of excavation for gravel base should be equal to the sum of the thickness of gravel base and finish layer actually to be used.
(4)
Embankments. It is intended that the mini-subdivision drive follow
natural grade plus or minus three feet, vertically, except for short
stretches. The regular six-foot shoulder cross section applies for
cut or fill in excess of plus or minus five vertical feet. Embankments
up to plus or minus three vertical feet may be stabilized by loam,
seed, and protective hay mulch or they may stabilized by at least
five inches of wood chips. Such minor embankments will generally not
require guardrails.
H.
Maintenance of completed way. The way is to remain permanently private property. Maintenance after formal completion (see § 130-19E, Completion, of this chapter) is the responsibility of the qualified homeowners' association which must be created, under § 125-34, Mini-subdivisions, of the Protective Bylaw, to assume responsibility for maintenance and snow removal and to manage common open space within the subdivision.
