[Adopted 6-6-1996]
Shared driveways shall be constructed to provide adequate access for emergency vehicles and shall meet the following minimum standards:
A. 
Widths. Traveled way shall be a minimum of 16 feet in width. Shoulders shall be two feet in width.
B. 
Construction. The center-line grade for any shared driveway shall not be less than 0.75% nor greater than 8%. Shared driveways shall be graded to allow stormwater to flow off the driveway at low points and to prevent puddling. Shared driveway construction specifications shall be the following:
(1) 
Compacted subgrade, free of frost, roots and debris.
(2) 
Six-inch gravel base conforming to Standard Specifications for Highways and Bridges (SSH&B) MI.03.0, Type B, compacted to a minimum of 95% of American Association of State Highway Transportation Officials (AASHTO) Test Designation T99 Compaction Test Method at optimum moisture content.
(3) 
Three inches dense graded crushed stone surface conforming to SSH & B M1.03.0, Type B, compacted to a minimum of 95% of AASHTO Test Designation T99 Compaction Test Method at optimum moisture content.
(4) 
The aprons for shared driveways shall be constructed to the bituminous sidewalk standard of the Planning Board's Subdivision Rules and Regulations [see Part 2 of this chapter, § 381-24A(1)], for the first 20 feet from the driveway intersection with the street. Shared driveways shall not direct stormwater runoff into the right-of-way of an existing street. Shared driveways can direct stormwater into the proposed right-of-way of a new subdivision road if the overall proposed stormwater management system is designed to accommodate the runoff.
C. 
Wiring. Utilities may be placed above ground unless the shared driveway provides access to lots located within a subdivision served by underground utilities.
D. 
Location. Shared driveways shall be located and designed so as to minimize conflict with traffic on public streets and to provide visibility and sight distances which are safe and adequate for observation of approaching vehicles and pedestrian traffic. A minimum sight distance in all directions shall be provided as follows. Shared driveways shall be set back a minimum of 10 feet from the property line, except in the location where the driveway accesses the public way, unless waived by the Planning Board.
[Amended 3-22-2007]
AASHTO Minimum Sight Distance1
Design Speed
(mph)
Minimum Sight Distance
(feet)
20
125
30
200
40
275
50
400
1
NOTE: AASHTO PGDHS-1990, Tables III-1 and III-5.
[Added 3-22-2007]
Any person who submits an application for a special permit for a shared driveway to the Board for approval shall file therewith the following:
A. 
A properly executed application form and certified list of abutters in accordance with the forms on file with the Planning Board.
B. 
Three full-size (24 inches by 36 inches) prints of the shared driveway plan, dark line on white background, and 20 reduced (11 inches by 17 inches) prints of the plan on eleven-by-seventeen-inch paper. Reduced prints will be referred by the Board to other Town officials for review.
C. 
A plan demonstrating that access is possible through lot frontage as required in § 218-23D, Shared driveways.
D. 
A plan demonstrating that the proposed shared driveway will provide adequate access for emergency vehicles.
E. 
Accompanying statements regarding any proposed access or utility easements.
F. 
Drainage specifications, including drainage calculations, for the proposed stormwater management system. A copy of the operating and maintenance plan for stormwater management system on 8 1/2 inches by 11 inches paper.
G. 
Every application for a special permit shall be accompanied by the fees specified in Chapter 381.
[Amended 2-18-2016]
Strict compliance with the requirements of these regulations may be waived when, in the judgment of the Planning Board, such action is in the public interest and not inconsistent with Groton Zoning Bylaw.[1]
[1]
Editor's Note: See Ch. 218, Zoning.