A. 
The subdivider shall observe all design standards for land subdivision as hereinafter provided. The design standards recognize the rural character of the Town and encourage design features that will maintain that character in the new subdivision. The standards incorporate requirements that minimize the effects of new roadways on the environment and on the streetscape of the surrounding roadway network. In order to minimize the effect of the proposed subdivision on Town services, design requirements that extend these services into the subdivision at the developer's expense are included. Wherever possible, designs requiring minimum maintenance are standard.
B. 
These standards shall be considered as minimum standards and shall be varied or waived only as provided for in Article VI.
The subdivision shall be conformity with the respective zoning requirements, and the general layout shall harmonize and conform with plans for Plympton, as adopted by the Planning Board.
The developer shall provide the Planning Board with one set of reproducible plans and three sets of prints of the completed subdivision. The plans must be prepared by a registered engineer and/or surveyor and clearly indicate the as-built location and elevation or roadways, utilities, and other required improvements.
A. 
Location and alignment.
(1) 
All streets in the subdivision shall be designed so that, in the opinion of the Planning Board, they will provide for safe vehicular travel. Due consideration shall also be given by the subdivider to the attractiveness of the street layout in order to obtain the maximum amenity of the subdivision. Long, straight roadway sections should be avoided on minor streets where possible.
(2) 
Provision satisfactory to the Planning Board shall be made for the proper projection of streets, or for access to adjoining property which is not yet subdivided.
(3) 
Reserve strips prohibiting access to streets or adjoining property shall not be permitted, except where, in the opinion of the Planning Board, such strips shall be in the public interest.
(4) 
Street jogs with center-line offset of less than 125 feet shall be avoided.
(5) 
The minimum center-line radius of curved streets shall be 150 feet. Greater radii may be required for secondary or major streets.
(6) 
All reverse curves shall be separated by a tangent at least 100 feet long.
(7) 
Streets shall be laid out so as to intersect as nearly as possible at right angles. No street shall intersect any other street at less than 75°.
(8) 
Property lines at street intersections shall be rounded or cut back to provide for a paved curb radius of not less than 25 feet.
B. 
Width.
(1) 
The minimum width of street rights-of-way shall be 50 feet. Greater width shall be required by the Planning Board when deemed necessary for sight distance at the intersections; right-of-way lines shall be rounded by tangent arcs with a minimum radius of 50 feet. This will result in the right-of-way width totaling at least 150 feet at the intersection.
(2) 
The typical cross section for minor streets shall conform to that indicated on Plate 4 (contained in the Appendix to the regulations).[1] The Planning Board may require greater paving sidewalk, and planting strip widths and curb requirements for major streets and secondary streets.
[1]
Editor's Note: The Appendix is included as an attachment to this chapter.
C. 
Grade.
(1) 
Grades of streets shall be not less than 1.0%. Grades shall not be more than 6.0% for major or secondary streets nor more than 8.0% for minor streets.
(2) 
All changes in grade exceeding 1% shall be connected by vertical curves of sufficient length to afford, in the opinion of the Planning Board, adequate sight distances.
(3) 
At all intersections, grades of streets shall not exceed 3% within a distance of 100 feet from the beginning of the intersection. Similarly grades of streets shall not exceed 1% within 50 feet from the beginning of the intersection. Proposed streets shall also have a negative slope for a distance of at least 50 feet from the beginning of the intersection.
D. 
Dead-end streets.
(1) 
A dead-end street shall include any single, continuous stretch of street that is open at one end and closed at the other end. For purposes of this section, any proposed street which intersects solely with a dead-end street shall be deemed to be an extension of the dead-end street. Dead-end streets and their extensions, if any, shall not be longer than 500 feet (measured between the side-line intersecting street and the center of the turnaround), unless, in the opinion of the Board, a greater length is necessitated by topography or other local conditions. The "side-line intersecting street" shall mean the nearest intersecting street that does not end in a dead end.
(2) 
A dead-end street shall not serve as frontage or access for more than eight dwellings or structures.
(3) 
A dead-end street shall be provided at any closed point with a cul-de-sac or turnaround having an outside paved roadway diameter of at least 120 feet or a temporary turnaround as directed by the Planning Board at its option. The width of pavement on the turnaround shall equal that of the servicing street.
(4) 
All permanent culs-de-sac or turnarounds shall be profiled along the center-line turning radius, and the center shall remain in a natural or landscaped conditions in a manner acceptable to the Board. The maximum profile grade for a cul-de-sac or turnaround shall be 3%.
(5) 
When and if a through connection is made in the future, the cul-de-sac or turnaround where the through connection is made shall be eliminated.
E. 
Street cross-section. The following information shall be the minimum acceptable for all streets. The Planning Board may require more where circumstances and intended use dictate.
(1) 
Two twelve-foot travel lanes for all minor and major secondary streets.
(2) 
At least four feet in width for road shoulder to be graded very closely to the profile of the street and sloped gradually toward the edge of the paved road unless otherwise directed.
(3) 
Location of roadway to conform to cross-section in Figure 4 (see Appendix).[2]
[2]
Editor's Note: The Appendix is included as an attachment to this chapter.
(4) 
All utilities, including electric, telephone, gas and cable TV, shall be underground unless directed otherwise by the Board.
(5) 
All poles servicing telephone, electric and other wires shall be located at least five feet from the edge of all new roads.
Easements for utilities across lots or centered on rear or side lot line shall be provided where necessary and shall be at least 20 feet wide. All stormwater structures not located in the roadway shall be placed in easements within subdivision lots with dimensions that contain all aspects of the structure needed for it to function, along with access for maintenance. In order to differentiate these easements from areas available to the lot owner, some landscape feature or other naturalistic measure shall be placed along its boundary. Possibilities include grade changes, existing tree lines or stone walls, landscape planting, etc.
Town Counsel: Potential Language to Consider: Easements for all surface and subsurface drainage structures shall be provided, as necessary and in a form that is acceptable to the Planning Board in consultation with Town Counsel, and shall be recorded prior to or simultaneously with the endorsed definitive plan to ensure that individual lot owners shall properly maintain or allow proper maintenance, repair and replacement of said structures, and said easements shall run to a homeowners' association.
Before approval of a plan, the Planning Board may also in proper cases require the plan to show a park or parks suitably located for playground or recreation purposes. The park or parks shall not be unreasonable in area in relation to the land being subdivided and to the prospective uses of such land. The Planning Board may, upon its endorsement of such plans, require that no building be erected upon such park or parks without its approval for a period of three years.
Pedestrian ways with sidewalk improvements should be located to provide convenient pedestrian circulation or access to nearby residential areas, schools, playgrounds, shopping centers, churches, transportation, parks, conservation areas, and other areas where improved pedestrian access is desirable. The pedestrian way shall consist of an easement or dedicated way having a right-of-way width of at least 15 feet.