A.
The Board shall not approve any subdivision plan unless
proposed street and stormwater management systems are designed in
accordance with any local ordinance or the specifications contained
in these regulations. Approval of the final plan by the Board shall
not be deemed to constitute or be evidence of acceptance by the municipality
of any street or easement.
B.
Subdividers shall submit to the Board, as part of
the final plan, detailed construction drawings showing a plan view,
profile and typical cross-section of the proposed streets. The plans
shall include the following information:
(1)
Date, scale and magnetic or true North point.
(2)
Intersections of the proposed street with existing
streets.
(3)
Roadway and right-of-way limits, including edge of
pavement, edge of shoulder, sidewalks and curbs.
(4)
Kind, size, location, material, profile and cross-section
of all existing and proposed drainage structures and their location
with respect to the existing natural waterways and proposed drainageways.
(5)
Complete curve data for all horizontal and vertical
curves.
(6)
Turning radii at all intersections.
(7)
Centerline gradients.
(8)
Locations of all existing and proposed overhead and
underground utilities, to include but not be limited to water, sewer,
electricity, telephone, lighting and cable television.
C.
Upon receipt of plans for a proposed public street,
the Board shall forward one copy to the municipal officers, the Road
Commissioner and the Municipal Engineer for review and comment. Plans
for streets which are not proposed to be accepted by the municipality
shall be sent to the Municipal Engineer for review and comment.
A.
These design standards shall be met by all streets
within subdivisions and shall control the roadway, shoulders, curbs,
sidewalks, drainage systems, culverts and other appurtenances.
B.
Streets shall be designed to discourage through traffic
within a residential subdivision.
C.
Wherever existing or other proposed streets, topography
and public safety permit, streets shall run in east-west directions
to maximize access for solar energy utilization. The character, extent,
width and grade of all streets shall be considered in their relation
to existing or planned streets.
D.
Reserve strips controlling access to streets shall
be prohibited except where their control is definitely placed in the
municipality.
E.
Adjacent to areas zoned and designed for commercial
use, or where a change of zoning to a zone which permits commercial
uses is contemplated by the municipality, the street right-of-way
and/or pavement width shall be increased on each side by half of the
amount necessary to bring the road into conformance with the standards
for commercial streets in these regulations.
F.
Where a subdivision borders an existing narrow street (not meeting the width requirements of the standards for streets in these regulations), or when the Comprehensive Plan indicates plans for realignment or widening of a road that would require use of some of the land in the subdivision, the plan shall indicate reserved areas for widening or realigning the road marked "Reserved for Road Realignment (Widening) Purposes." Land reserved for such purposes may not be included in computing lot area or setback requirements of Chapter 105, Zoning. When such widening or realignment is indicated on the Official Map, the reserve area shall not be included in any lot but shall be reserved to be deeded to the municipality or state.
G.
Where a major subdivision abuts or contains an existing
or proposed arterial street, no residential lot may have vehicular
access directly on to the arterial street. This requirement shall
be noted on the plan and in the deeds of any lot with frontage on
the arterial street.
H.
Any subdivision containing 15 dwelling units or more
shall have at least two street connections with existing public streets,
streets shown on an Official Map or streets on an approved subdivision
plan for which performance guaranties have been filed and accepted.
Any street serving 15 dwelling units or more shall have at least two
street connections leading to existing public streets, streets shown
on an Official Map or streets on an approved subdivision plan for
which performance guaranties have been filed and accepted.
I.
The following design standards apply according to
street classification:
[Amended 3-9-2019 ATM
by Art. 4; 3-11-2022 ATM by Art. 72]
Type of Street
| |||||
---|---|---|---|---|---|
Description
|
Arterial
|
Collector
|
Minor
|
Private Way
|
Industrial/ Commercial
|
Minimum right-of- way width (feet)
|
80
|
50
|
50
|
50
|
80
|
Minimum pavement width (feet)
|
44
|
24
|
202
|
121
|
44
|
Minimum grade
|
.5%
|
.5%
|
.5%
|
N/A
|
5%
|
Maximum grade
|
5%
|
6%
|
6%
|
10%
|
5
|
Minimum centerline radius (feet)
|
800
|
230
|
150
|
N/A
|
800
|
Minimum tangent between curves of reverse
alignment (feet)
|
300
|
200
|
100
|
N/A
|
300
|
Roadway crown (inches)
|
1/4/ft.
|
1/4/ft.
|
1/4/ft.
|
N/A
|
1/4/ft.
|
Minimum angle of street intersections
|
90°
|
90°
|
90°
|
90°
|
90°
|
Maximum grade within 75 feet of intersection
|
2%
|
2%
|
2%
|
N/A
|
2%
|
Minimum curb at intersection (feet)
|
30
|
20
|
15
|
N/A
|
30
|
Minimum right-of- way radii at intersections
(feet)
|
20
|
10
|
10
|
10
|
20
|
Minimum width of shoulders, each side
(feet)
|
3
|
3
|
3
|
3
|
9
|
NOTES:
|
---|
1Pavement requirement for a private
way in a minor subdivision may be at the Board's discretion.
|
2Pavement requirement for a minor
subdivision street may be at the Board's discretion.
|
J.
The center line of the roadway shall be the center
line of the right-of-way.
K.
Dead-end streets. In addition to the design standards
above, dead-end streets shall be constructed to provide a cul-de-sac
turnaround with the following requirements for radii: Property line
65 feet; outer edge of pavement 50 feet. The Board may require the
reservation of a twenty-foot easement in line with the street to provide
continuation of pedestrian traffic or utilities to the next street.
The Board may also require the reservation of a fifty-foot easement
in line with the street to provide continuation of the road where
future subdivision is possible.
L.
Grades, intersections and sight distances.
(1)
Grades of all streets shall conform in general to
the terrain, so that cut and fill are minimized while maintaining
the grade standards above.
(2)
All changes in grade shall be connected by vertical
curves to provide for the minimum sight distances below.
(3)
New street intersections or driveway curb cuts.
(a)
Where new street intersections or driveway curb
cuts are proposed, sight distances, as measured along the road onto
which traffic will be turning, shall be based upon the posted speed
limit and conform to the table below:
Posted speed limit (mph)
|
25
|
30
|
35
|
40
|
45
|
50
|
55
|
Sight distance (feet)
|
250
|
300
|
350
|
400
|
450
|
500
|
550
|
(b)
Where necessary, corner lots shall be cleared
of all growth and sight obstructions, including ground excavation,
to achieve the required visibility.
(4)
Cross (four-cornered) street intersections shall be
avoided insofar as possible, except as shown on the Comprehensive
Plan or at other important traffic intersections. A minimum distance
of 200 feet shall be maintained between center lines of side streets.
N.
Where installed, curbing shall be granite or bituminous
concrete and shall be installed on a thoroughly compacted gravel base
of six inches minimum thickness, except that bituminous curbing shall
be installed on the base course of the pavement. The specified pavement
width above shall be measured between the curbs.
A.
Minimum thickness of material after compaction shall
be as follows:
[Amended 3-11-2022 ATM by Art. 72]
Type of Street
| |||||
---|---|---|---|---|---|
Minimum Requirements
| |||||
Street
|
Arterial
|
Collector
|
Minor
|
Private Way
|
Industrial/ Commercial
|
Aggregate subbase course (inches) (maximum
sized stone 4 inches)
|
18
|
18
|
18
|
12
|
18
|
Crushed aggregate base course (inches)
|
4
|
3
|
3
|
3
|
4
|
Hot bituminous pavement (inches)
| |||||
Total thickness
|
3 1/4
|
2 1/2
|
2 1/21
|
3
| |
Surface course
|
1 1/2
|
3/4
|
3/41
|
1 1/4
| |
Base course
|
1 3/4
|
1 3/4
|
1 3/41
|
1 3/4
|
NOTES:
|
1Pavement requirement for a minor
subdivision street may be at the Board's discretion.
|
B.
Preparation.
(1)
Before any clearing has started on the right-of-way,
the center line and side lines of the new road shall be staked or
flagged at fifty-foot intervals.
(2)
Before grading is started, the entire right-of-way
shall be cleared of all stumps, roots, brush and other objectionable
material. All ledge, large boulders and tree stumps shall be removed
from the right-of-way.
(3)
All organic materials shall be removed to a depth
of two feet below the subgrade of the roadway. Rocks and boulders
shall also be removed to a depth of two feet, or a depth meeting the
Road Commissioner's approval, below the subgrade of the roadway. On
soils which have been identified by the Town Engineer as not suitable
for roadways, the subsoil shall be removed from the street site to
a depth of two feet below the subgrade and replaced with material
meeting the specifications for gravel aggregate subbase below.
(4)
Side slopes shall be no steeper than a slope of three
feet horizontal to one foot vertical, and shall be graded, limed,
fertilized and seeded according to the specifications of the erosion
and sedimentation control plan.
(5)
All underground utilities shall be installed prior
to paving to avoid cuts in the pavement. Building sewers and water
service connections shall be installed to the edge of the right-of-way
prior to paving.
C.
Bases and pavement.
(1)
Bases.
(a)
Aggregate subbase course.
[1]
The aggregate subbase course shall be sand or
gravel of hard durable particles free from vegetative matter, lumps
or balls of clay and other deleterious substances. The gradation of
the part that passes a three-inch square mesh sieve shall meet the
following grading requirements:
Sieve Designation
|
Percentage by Weight Passing Square Mesh
Sieves
| |
---|---|---|
1/4-inch
|
25% to 70%
| |
No. 40
|
0% to 30%
| |
No. 200
|
0% to 7%
|
[2]
Aggregate for the subbase shall contain no particles
of rock exceeding four inches in any dimension.
(b)
Aggregate base course.
[1]
The aggregate base course shall be sand or gravel
of hard durable particles free from vegetative matter, lumps or balls
of clay and other deleterious substances. The gradation of the part
that passes a three-inch square mesh sieve shall meet the following
grading requirements:
Sieve Designation
|
Percentage by Weight Passing Square Mesh
Sieves
| |
---|---|---|
1/2-inch
|
45% to 70%
| |
1/4-inch
|
30% to 55%
| |
No. 40
|
0% to 20%
| |
No. 200
|
0% to 5%
|
[2]
Aggregate for the base shall contain no particles
of rock exceeding four inches in any dimension.
(2)
Pavement joints. Where pavement joins an existing
pavement, the existing pavement shall be cut along a smooth line and
form a neat, even, vertical joint.
(4)
Pavements.
(a)
Minimum standards for the base layer of pavement
shall be the M.D.O.T. specifications for plant mix grade B with an
aggregate size no more than one inch maximum.
(b)
Minimum standards for the surface layer of pavement
shall meet the M.D.O.T. specifications for plant mix grade C with
an aggregate size no more than 3/4 inch maximum.
A.
Adequate provision shall be made for disposal of all
stormwater generated within the subdivision and any drained groundwater
through a management system of swales, culverts, underdrain and storm
drains. The stormwater management system shall be designed to conduct
stormwater flows to existing watercourses or storm drains.
(1)
All components of the stormwater management system
shall be designed to meet the criteria of a twenty-five-year storm
based on rainfall data for Portland, Maine.
(2)
The minimum pipe size for any storm drainage pipe
shall be 12 inches. Maximum trench width at the pipe crown shall be
the outside diameter of the pipe plus two feet. Pipe shall be bedded
in a fine granular material, containing no stones larger than three
inches, lumps of clay or organic matter, reaching a minimum of six
inches below the bottom of the pipe extending to six inches above
the top of the pipe.
(3)
Catch basins shall be installed where necessary and
located at the curbline.
(4)
Outlets shall be stabilized against soil erosion by
stone riprap or other suitable materials to reduce stormwater velocity.
B.
The stormwater management system shall be designed
to accommodate upstream drainage, taking into account existing conditions
and approved or planned developments not yet built and shall include
a surplus design capacity factor of 25% for potential increases in
upstream runoff.
C.
Downstream drainage requirements shall be studied
to determine the effect of the proposed subdivision. The storm drainage
shall not overload existing or future planned storm drainage systems
downstream from the subdivision. The subdivider shall be responsible
for financing any improvements to existing drainage systems required
to handle the increased storm flows.
D.
Wherever the storm drainage system is not within the
right-of-way of a public street, perpetual easements shall be provided
to the Town allowing maintenance and improvement of the system.
E.
Where soils require a subsurface drainage system,
the drains shall be installed and maintained separately from the stormwater
drainage system.
A.
Materials.
(1)
Reinforced concrete pipe. Reinforced concrete pipe
shall meet the requirements of ASTM Designation C-76 (AASHTO M 170).
Pipe classes shall be required to meet the soil and traffic loads
with a safety factor of 1.2 on the .01 inch crack strength with a
Class B bedding. Joints shall be of the rubber gasket type meeting
ASTM Designation C 443-70, or of an approved preformed plastic jointing
material such as Ramnek. Perforated concrete pipe shall conform to
the requirements of AASHTO M 175 for the appropriate diameters.
(2)
Asbestos-cement pipe. Asbestos-cement pipe shall meet
the requirements of ASTM Designation C-428 (AASHTO M 189). Pipe classes
shall be required to meet the soil and traffic loads with a safety
factor of 1.5 on the crushing strength. Joints shall be of the rubber
gasket type meeting ASTM Designation D-1869-63, or of an approved
preformed plastic sleeve type.
(3)
Corrugated metal pipe. Corrugated metal pipe shall
be bituminous coated meeting the requirements of AASHTO Designation
M 190 Type C for iron or steel pipe or AASHTO Designation M 196 for
aluminum alloy pipe for sectional dimensions and type of bituminous
coating. Pipe gauge shall be as required to meet the soil and traffic
loads with a deflection of not more than 5%.
(4)
ABS pipe. ABS (Acrylonitrile-butadiene-styrene) composite
pipe and fittings shall conform to the requirements of AASHTO M 264
and AASHTO M 265. Perforated pipe shall conform to the requirements
of AASHTO M 36, Type III.
(5)
Corrugated plastic pipe. Corrugated plastic pipe shall
conform to the requirements of AASHTO M-252.
(6)
Manholes. Manholes shall be of precast concrete truncated
cone section construction meeting the requirements of ASTM Designation
C 478 or precast concrete manhole block construction meeting the requirements
of ASTM Designation C 139, radial type. Bases may be cast in place
3,000 pounds per square inch, twenty-eight-day strength concrete or
may be of precast concrete, placed on a compacted foundation of uniform
density. Metal frames and traps shall be set in a full mortar bed
and with tops shall conform to the requirements of AASHTO M 103 for
carbon steel castings, AASHTO M 105, Class 30 for gray iron castings
or AASHTO M 183 (ASTM A 283, Grade B or better) for structural steel.
(7)
Catch basins. Catch basins shall be of precast concrete
truncated cone section construction meeting the requirements of ASTM
Designation C 478 or precast concrete manhole block construction meeting
the requirements of ASTM Designation C 139, radial type. Castings
shall be square cast iron sized for the particular inlet condition
with the gratings perpendicular to the curbline. Bases may be cast
in place 3,000 pounds per square inch (psi) twenty-eight-day strength
concrete or may be of precast concrete, placed on a compacted foundation
of uniform density. Metal frames and traps shall be set in a full
mortar bed and with tops shall conform to the requirements of AASHTO
M 103 for carbon steel castings, AASHTO M 105, Class 30 for gray iron
castings or AASHTO M 183 (ASTM A 283, Grade B or better) for structural
steel.
B.
Drain inlet alignment shall be straight in both horizontal
and vertical alignment unless specific approval of a curvilinear drain
is obtained, in writing, from the Board, after consultation with the
Municipal Engineer.
C.
Manholes shall be provided at all changes in vertical
or horizontal alignment and at all junctions. On straight runs, manholes
shall be placed at a maximum of four-hundred-foot intervals.
D.
Upon completion, each catch basin or manhole shall
be cleaned of all accumulation of silt, debris or foreign matter and
shall be kept clean until final acceptance.
A.
Erosion control. The procedures outlined in the erosion
and sedimentation control plan shall be implemented during the site
preparation, construction and cleanup stages.
B.
Cleanup. Following street construction, the developer
or contractor shall conduct a thorough cleanup of stumps and other
debris from the entire street right-of-way. If on-site disposal of
the stumps and debris is proposed, the site shall be indicated on
the plan and be suitably covered with fill and topsoil, limed, fertilized
and seeded.
C.
Street names, signs and lighting. Streets which join
and are in alignment with streets of abutting or neighboring properties
shall bear the same name. Names of new streets shall not duplicate,
nor bear phonetic resemblance to the names of existing streets within
the municipality and shall be subject to the approval of the Board.[1] No street name shall be the common given name of a person.
The developer shall reimburse the municipality for the costs of installing
street name, traffic safety and control signs. Streetlighting shall
be installed as approved by the Board.
Upon completion of street construction and prior
to a vote by the municipal officers to submit a proposed public way
to the legislative body, a written certification signed by a professional
engineer registered in the State of Maine shall be submitted to the
municipal officers at the expense of the applicant, certifying that
the proposed way meets or exceeds the design and construction requirements
of these regulations. As-built plans shall be submitted to the municipal
officers.