The subdivider shall observe the following requirements and principals of land subdivision in the design of each subdivision or portion thereof.

The subdivision plat shall conform to design standards that will encourage good development patterns within the municipality. Where either or both an official map or master plan has or have been adopted, subdivision shall conform to the proposals and conditions shown thereon. The streets, drainage rights-of-way, school sites, public parks and playgrounds shown on an officially adopted master plan or official map shall be considered in approval of subdivision plats. Where no master plan or official map exists, streets and drainage rights-of-way shall be shown on the final plat, and shall be such as to lend themselves to the harmonious development of the municipality and enhance the public welfare in accordance with the following design standards:

a. The arrangement of streets not shown on the master plan or official map shall be such as to provide for the appropriate extension of existing streets.

b. Subdivisions abutting arterial streets shall provide a marginal service road or reverse frontage with a buffer strip for planting, or some other means of separation of through and local traffic as the planning board may determine appropriate.

c. The right-of-way width of every street shall be measured from lot line to lot line and shall not be less than 50 feet in width, or such greater width as shown on the official map of the adopted master plan, except that the planning board, in its discretion, may permit marginal access streets and alleys having a width of not less than 40 feet.

The right-of-way width for internal roads in commercial and industrial developments shall be determined on an individual basis, and shall in all cases be of sufficient width and design to safely accommodate the maximum traffic, parking and loading needs and maximum access for fire fighting equipment.

d. No subdivision showing reverse strips controlling access to streets shall be approved except where the control and disposal of land comprising such strips has been placed with the governing body under conditions approved by the planning board.

e. Subdivisions that adjoin or include existing streets that do not conform to widths as shown on the master plan or official map or the street width requirements of this chapter shall dedicate additional width along either one or both sides of said road. If the subdivision is along one side only, one-half of the required extra width shall be dedicated.

f. Grades of arterial and collector streets shall not exceed four percent. Grades on other streets shall not exceed ten percent. No street shall have a minimum grade of less than one-half of one percent.

g. Street intersections shall be as nearly at right angles as is possible and in no case be less than 60 degrees. The block corners at intersections shall be rounded at the curb line with the curve having a radius of not less than 25 feet.

h. Street jogs with center line offsets of less than 125 feet shall be prohibited.

1. A tangent at least 100 feet long shall be introduced between reverse curves on arterial and collector streets.

j. When connecting street lines deflect from each other at any one point by more than ten degrees and not more than 45 degrees, they shall be connected by a curve with a radius of not less than 100 feet for minor streets and 300 feet for arterial and collector streets.

k. All changes in grade shall be connected by vertical curves of sufficient radius to provide a smooth transition and proper sight distance.

l. Dead-end streets shall not be longer than 600 feet and shall provide a turn around at the end with a radius of not less than 50 feet and tangent whenever possible to the right side of the street.

If a dead-end street is of a temporary nature, a similar turn around shall be provided and provisions made for future extension of the street and reversion of the excess right-of-way to the adjoining properties.

m. No street shall have a name which will duplicate or so nearly duplicate as to be confused with the names of existing streets. The continuation of an existing street shall have the same name.

n. Where a tract is subdivided into larger parcels than ordinary building lots such parcels shall be arranged so as to allow the opening of future streets and logical further subdivisions.

0. Private streets shall not be approved nor shall public improvements be approved for any private street.

a. Block length and width of acreage within bounding roads shall be such as to accommodate the size of lots required in the area by the zoning ordinance and to provide for convenient access, circulation control and safety of street traffic. Block lengths shall not, under any circumstances, exceed 1,200 feet.

b. In blocks over 1,000 feet long, pedestrian crosswalks may be required in locations deemed necessary by the planning board. Such walkway shall be ten feet wide and be straight from street to street.

c. For commercial, group housing, or industrial use, block size shall be sufficient to meet all area and yard requirements for such use.

a. Lot dimensions and area shall not be less than the requirements of the zoning ordinance.

b. Insofar as is practical, lots shall be rectangular in shape with side lot lines at right angles to straight streets and radial to curved streets.

c. Each lot must front upon an approved street at least 50 feet in width, except lots fronting on marginal access streets described in subsection 19-8.2c of this section.

d. Where extra width has been dedicated for widening of existing streets, lots shall begin at such extra width line, and all setbacks shall be measured from such line.

e. Where there is a question as to the suitability of a lot or lots for their intended use due to factors such as shape, sight distances, topography, rock formations, wetlands, flood conditions or similar circumstances, the planning board may, after adequate investigation withhold approval of such lots.

f. Corner lots for residential use shall have extra width to permit appropriate building setbacks from and orientation to both streets.

a. In large scale development, easements along rear property lines or elsewhere for utility installation may be required. Such easements shall be at least 15 feet wide and located in consultation with the companies or municipal departments concerned.

b. Where a subdivision is traversed by a watercourse, drainage way channel, or stream, there shall be provided a storm water easement or drainage right-of-way conforming substantially with the line of such watercourse, and such further width or construction, or both, as will be adequate for the purpose.

c. Natural features of every lot shall be sufficient to provide amply for the front, rear and side yard requirements of the zoning ordinance of the town for the district or zone within which the land is located and the use to which the land is intended to be used.