(a) The length, width, and shape of a block shall be determined with due regard to the following:
(1) Provisions for an adequate number of building sites which contain the necessary area for the particular need and use intended as specified by these regulations and any involved zoning regulations.
(2) The need for convenient access, circulation control, and safety of street traffic.
(3) The limitation of topography.
(b) Blocks shall not exceed 1,600 feet in length. A crosswalk, the right-of-way of which shall not be less than ten feet, shall be required, if in the opinion of the Planning Board and Commission, when involved, this facility is necessary.