A.
Streets: general principles. Streets must be designed to integrate
with the topography and natural features and provide safe travel for
all users of the street. Streets shall be designed to move vehicle
and pedestrian traffic safely. Any new street or road approved through
the development review process shall be based upon the written recommendations
of the Public Works Director, Town Engineer, Fire Chief, Police Chief,
and Director of Planning and Development, who shall review the project
for safety and the capacity to serve all users. Design of streets
shall address pedestrian and bicycle safety and movement.
B.
All new streets shall be classified based upon the standards found in Appendix A, Table 1, [1] and incorporate the following standards:
(1)
Sight distance. Any intersecting street or road shall be so designed
in profile and grading to provide minimum sight distances measured
in each direction. Measurement shall be from 10 feet behind the travel
way line with the height of eye three and one half (3.5) feet above
the pavement and a height of object of four and one quarter (4.25)
feet.
|
Allowable Speed
Distance *
(miles per hour)
|
Minimum Sight
(in feet)
| |
|---|---|---|
|
25
|
200
| |
|
30
|
250
| |
|
35
|
305
| |
|
40
|
360
| |
|
45
|
425
| |
|
50
|
495
| |
|
55
|
570
|
|
NOTES:
| ||
|---|---|---|
|
*
|
Based on MDOT standards, if 30% or more of the traffic are large
trucks, there may be a need for greater sight distances.
| |
(2)
Driveways. Driveway placement shall be such that an exiting vehicle
has an unobstructed sight distance according to the above schedule.
Driveways to corner lots shall gain access from the street of lower
classification when a corner lot is bounded by streets of two different
classifications.
(3)
Signs. The installation of street name signs and other traffic control
signs shall be the responsibility of the developer as directed by
the Planning Board and in conformance with the requirements of the
Department of Public Works. All signs shall be erected in conformance
with the latest edition of the Manual on Uniform Traffic Control Devices
(MUTCD).
(4)
Curbs. Curbing shall be required where grades require that stormwater
drainage be channeled along the curbline to avoid shoulder erosion,
and with typical sections as noted in this code.
(5)
Utility easements. Easements are required for sewers, storm drains,
public water supplies and other utilities located outside of proposed
rights-of-way. Utility easements in general shall not be less than
20 feet in width and in specific cases may require increased width,
as recommended by the Public Works Director or the Director's designee.
(6)
Sidewalks. At the discretion of the Planning Board, sidewalks may
be provided within all subdivisions or other development review where
a potential connection to the existing sidewalk network is provided
for the safety and convenience of the public, per the standards in
Table 1. The sidewalk location as depicted in the cross section figures
is preferred; however, it may, at the discretion of the Planning Board,
be positioned at curbline with zero esplanade. Sidewalks, when required,
shall be a minimum of five (5) feet in width.
[1]
Editor's Note: Table 1 is included as an attachment to this chapter.
C.
Design characteristics.
(1)
The proposed street system shall be integrated within the existing
street network.
(2)
The pattern of circulation should be obvious to the motorists, with
local streets subordinate to collector streets. Pavement width, street
alignment, frequency and degree of curves, setback of homes, landscaping
or other means should heighten the distinction between local and collector
streets. Local streets should discourage through traffic by the use
of curves, or other means to slow traffic speeds.
(3)
Street layout shall reflect the natural terrain and special features
and retain those features to the best extent practicable. Areas of
cut and fill shall be minimized to inhibit erosion. Drainage shall
utilize natural systems, where possible, with adequate protection
against erosion.
(4)
Reserved streets for future street connections to adjoining undeveloped
property shall be required by the Board to be dedicated to the Town.
The developer of the adjoining property can be required by the Board
to connect to and build over the reserved strips. Reserved strips
not to be used shall be dispensed with according to 23 M.R.S.A. § 3027.
(5)
Street design shall conform to the following standards. Road classification
shall be determined by the Planning Board in accordance with Table
1. Intersections should be at angles in accordance with Table 1. Distance
between street intersections should be in accordance with Table 1.
A.
This section sets the minimum standards for public street, sidewalk
and utilities construction:
(1)
Roadway construction materials standards shall conform to the current
"State of Maine Department of Transportation Standard Specifications."
(2)
The Standards and Dimensions contained in Tables 1 and 2[1] shall be considered minimums.
[1]
Editor's Note: Tables 1 and 2 are included as attachments to this chapter.
B.
Construction.
(1)
Engineering work. All engineering work, including the setting of
grade stakes necessary for the construction of the street and sidewalks,
and storm sewers, shall be performed by the developer at his or her
expense.
(2)
Underground utilities. Any sewers and appurtenances, drains, including
house drains and catch basins which are to be built in the street
or sidewalk, and all underground utilities and their respective services
shall be constructed before any road material is placed. Underground
utilities, although not required, are encouraged for every new proposed
street.
(3)
Sewers. Sanitary sewer pipes and appurtenances must be installed
in conformance with the requirements of the Topsham Sewer District.
(4)
Grading. All streets, roads, walks, etc., shall be graded to their
full width by the developer so that pavements and sidewalks can be
constructed on parallel profiles.
(5)
Preparation. Before grading is started, the right-of-way area shall
be cleared of all stumps, roots, brush and other objectionable material
and all trees not intended for preservation, as designated by the
Public Works Director of the Director's designee.
(6)
Cuts. Tree stumps and other organic materials shall be removed to
a minimum depth of 2 feet below the subgrade. Rock and boulders, when
encountered, shall be removed to subgrade.
(7)
Fill. All material used in the construction of embankments shall
be of the quality to meet the standards for embankment construction,
Section 203 of the Maine Department of Transportation Standard Specifications,
except that compaction shall not be less than 95% of maximum density
(per ASTM D 1557 Mod.). Excess materials, including organic materials,
soft clays, wet and noncompactable materials, etc., shall be removed
from the street site. The fill shall be spread in layers not to exceed
8 inches loose and then compacted. The filling of utility trenches
shall be mechanically compacted.
(8)
Side slopes. All side slopes shall not exceed a slope of 3 horizontal
to 1 vertical unless shown otherwise on typical cross sections in
Figures 1 through 3B.[2]
[2]
Editor's Note: Said figures are included as attachments to this chapter.
(9)
Bases and pavement. The appropriate sections of the Bases and Pavements
Divisions of the Maine Department of Transportation Standard Specifications
currently in effect at the date of submission of the preliminary plan
shall be applicable to this section except as follows:
(b)
Pavement.
[1]
Where pavement placed joins an existing pavement, the existing
pavement shall be ground and cut along a smooth line and to a neat,
even, shiplap joint. Broken or raveled edges will not be permitted,
nor deviation from grade. A tack coat shall be applied to all joints
prior to placement of new pavement.
[2]
Bituminous asphalt intended for placement as base or wearing
roadway course shall be an approved MDOT mix. Mix designs will be
provided to the Public Works Director or the Director's designee,
for approval, prior to placement. Unless otherwise submitted and approved,
bituminous asphalt cement base and wearing course shall meet the following
specifications:
[3]
Placement of bituminous pavement will be subject to calendar
and temperature limitation as specified in the MDOT Standard Specifications
Section 401.06 Weather and Seasonal Limitations for b. Zone 2 or with
the approval of the Public Works Director.
[4]
Core samples of the base pavement will be conducted at the direction
of the Public Works Director or the Director's designee and the cost
of the coring will be paid for by the applicant.
[5]
Where the average coring thickness of base pavement is less
than that specified in Table 2[3] (minimum standards and dimensions), the shortfall will
be calculated and the resultant tonnage will be added to the specified
wearing course depth in accordance to the correction table as follows:
|
BASE PAVEMENT CORRECTION TABLE
| ||
|---|---|---|
|
Average Coring Thickness
|
Corrective Action
| |
|
1 3/4 inch to 2 1/2 inch (up to 3/4 inch deficient)
|
Calculated tonnage of pavement deficiency will be doubled and
added to the specified overlay.
| |
|
1 3/4 inches or less
|
Additional "2 inch" lift of base pavement will be the standard
corrective action. However, the Public Works Director may require
additional corings (the number will be determined by the Director
of Public Works) which will be evaluated, by a MDOT certified lab,
for gradation, % bitumen, and compaction at the applicant's expense.
After an analysis of results, the Town may require the initial base
pavement to be removed and a new base pavement placed in accordance
with appropriate specifications.
| |
[3]
Editor's Note: Table 2 is included as an attachment to this chapter.
(10)
Curbing.
(b)
All curbing shall be constructed per Section 609 of the Maine
Department of Transportation Standard Specifications, except as follows:
[1]
Granite curbing shall be provided at all street intersections
with radii less than 50 feet where curbing is proposed or required.
All other areas with greater than 50 feet radii will be evaluated
as site conditions dictate. A minimum reveal of 7 inches shall be
required.
[2]
Cape Cod slipform concrete curbing may be utilized in lieu of
other curbing when approved by the Public Works Director or the Director's
designee.
(11)
Sidewalks. Section 608 of the State of Maine Department of Standard
Specifications shall apply. Aggregate to build new sidewalks shall
meet the requirements of Section 703.06(a) Type A.
(12)
Driveways. All driveway aprons shall be paved with four (4)
inches of bituminous concrete. The paved apron will extend from the
edge of the existing roadway edge and will extend to the limit of
the public right-of-way. Paved aprons will be a minimum of 12 feet
in width having five (5) foot radii, minimum.
(13)
Dead end street turnarounds.
(a)
Cul-de-sacs and dead end streets that provide the sole vehicular
access to improved or improvable land shall be provided with a suitable
turning circle or turnaround, as applicable, at the closed end.
[1]
A hammerhead turnaround shall be constructed and paved to specified
street standards, whether temporary or permanent, for a distance of
50 feet from the roadway edge at ninety degrees (90°) to the street
it serves.
[3]
Temporary turnarounds may be allowed where future road extensions
are planned if designed to allow discontinuance of the turning circle
while not creating any lots with less than the required frontage for
the zone in which located.
[4]
Loop roads that provide the sole vehicular access to developable
or improved land shall meet the required centerline radii and minimum
tangent distance between curves shown in Table 1[4] and shall be constructed and paved to specified street
standards.
[4]
Editor's Note: Table 1 is included as an attachment to this chapter.
[5]
Driveways shall not be located off the ends of hammerhead turnarounds.
C.
Storm drainage design standards.
(1)
Intent. An adequate piped storm drainage system, including appurtenances
such as catch basins and manholes, shall be provided for proper drainage
of stormwater collected in streets and areas tributary to the street
system. Discharge of the collected storm drainage shall be by piped
system or ditches when approved by the Planning Board. Appropriate
conveyances for outlets to drainage systems must be provided. Drainage
easements must be a minimum width of 30 feet.
(2)
Design standards. All stormwater systems within the subdivision shall
be designed to meet the criteria of two-year and twenty-five-year
storms. Flows shall be computed by the TR-55, TR-20, or Rational methods
as appropriate, with design computations being submitted for approval.
All stormwater management plans shall be completed by, or under the
supervision of and signed by, a Maine registered professional engineer.
(a)
Upstream drainage shall be accommodated by an adequately sized
system through the proposed subdivision for existing conditions and
future potential development in the upstream drainage area or areas
tributary to the proposed subdivision, as determined by the Planning
Board.
(b)
Existing downstream drainage facilities shall be studied to
determine the effect of the proposed subdivision's drainage. The developer
shall demonstrate to the satisfaction of the Planning Board that the
storm drainage from the proposed subdivision will not, in any way,
overload existing storm drainage systems downstream from the proposed
subdivision.
(c)
Three hundred feet shall be considered as the maximum length
for carrying open stormwater in a street gutter prior to intake at
a catch basin. No stormwater will be permitted to drain across a street
or across an intersection.
(d)
Design standards for drainage systems shall be approved by the
Planning Board. Minimum pipe size for any storm drainage pipe shall
be 12 inches.
(e)
Where open ditches, channels, streams or natural drainage courses
are used, either to collect or discharge stormwater, adequately sized
perpetual easements shall be provided. Minimum width shall be 30 feet.
Approval of the Planning Board shall be required for any open storm
drainage system.
(f)
Where surficial soils and/or the road typical section are of
the nature requiring an underdrainage system, underdrains shall be
installed and discharged in a positive manner.
(g)
House foundation drains may be connected to the storm drainage
system upon approval by and under the direction of the Director of
Public Works.
D.
Storm drain construction standards. The following material shall
be utilized for storm drain construction and provided and installed
in accordance with State of Maine Department of Transportation Standards
and Specifications:
(1)
Reinforced concrete pipe.
(2)
Corrugated metal pipe.
(3)
Corrugated smooth bore polyethylene pipe.
(4)
Underdrain pipe. Underdrain pipe may be perforated PVC or HDPE. Minimum
diameter of underdrain piping shall be 6 inches when used to provide
roadway subgrade drainage. Perforated tubing shall not be permitted.
(5)
Manholes. Manholes shall be of precast concrete construction. Precast
sections shall meet the requirements of ASTM Designation C-478. Castings
shall be of cast iron meeting Topsham Sewer District standards for
sewer construction.
(6)
Catch basins. Catch basins shall be of precast concrete construction.
Castings shall be square cast iron as required for the particular
inlet condition with the gratings perpendicular to the curbline. All
catch basins shall be provided with a Type 1 curb face inlet when
the typical road section is curbed.
E.
General construction requirements.
(1)
Trenching. All trenching shall be accomplished in accordance with
all appropriate state and federal safety requirements.
(2)
Trench width. Trench width at the pipe crown shall be 4/3 the inside
diameter of the pipe plus one foot six inches, with a minimum trench
width of 3 feet.
(3)
Pipe bed. Pipe bedding and backfill shall be undertaken in accordance
with MDOT Standard Specifications.
(4)
Drain alignment. Drain alignment shall be straight in both horizontal
and vertical alignment unless specific approval of a curvilinear drain
is obtained in writing from the Director of Public Works or his designee.
(5)
Drain outlets. All drain outlets shall be riprapped to prevent erosion.
Facilities for energy dissipation shall be provided.
(6)
Underdrains. Underdrains shall be laid with perforations down, with
a crushed stone envelope wrapped in an appropriate nonwoven fabric,
unless it is also functioning as a stormdrain, in which case perforations
would be up.
F.
Water district standards. Water pipes and related equipment, such
as hydrants and main gate valves, must be constructed to serve all
lots of the subdivision in conformity with the standards of the Brunswick-Topsham
water district.
G.
Utility capacity. All utilities installed must have a capacity judged
by the Planning Board to meet foreseeable future requirements.
H.
Backfilling utilities. No subsurface utility installation may be
backfilled until it has been inspected and approved by the appropriate
review authority and confirmed by the Topsham Code Enforcement Officer.
I.
Monumentation. The right-of-way lines of streets to be accepted shall
be marked with 3/4 inch diameter iron pins. All other lot corners
shall be marked with iron pipe or rod not less than 3/4 inch in diameter
and 36 inches long, set flush with the finished grade.
J.
Planting. Lots shall be landscaped with trees and shrubs of a type
natural to the area. These must be planted at a rate of at least two
trees per house lot and be bonded for one year. The Board may, however,
grant variances on this requirement in consideration of natural trees
remaining on the house lot.
K.
Inspections. The developer shall coordinate the construction of streets,
drains, sewers, and utilities with the responsible agencies. The Town
Planner shall work with the developer to schedule a preconstruction
meeting. The developer shall present his construction program and
schedule inspections. At a minimum, the Director of Public Works (and/or
his designee), the Superintendent of the Topsham Sewer District (and/or
his designee), and the Town Planner shall be contacted by the developer
to schedule inspections. When a minimum length of 300 feet (or the
entire length of a street if it is less than 300 feet in length) has
been excavated to subgrade and properly prepared for the placement
of gravel, the Public Works Department must be called to perform an
inspection and approval granted before gravel is placed. Gravel shall
be placed in compacted layers of not more than 8 inches. Before any
surface material is placed in any area, the work shall again be inspected
by the Director of Public Works. The placement of bituminous concrete
shall be in accordance with this chapter, and be inspected by the
Department of Public Works. Prior to any sewer construction, necessary
permits shall be obtained from the Topsham Sewer District. A representative
of the District shall be present whenever an existing sewer is to
be cut, entered, or in any way disturbed. The Sanitary District is
to be notified immediately if any of its lines are damaged or in need
of repair. All utilities must certify in writing that the work has
been accomplished to their satisfaction prior to acceptance by the
Town of any street or way.
