The following regulations shall govern the design and layout of blocks:
(b) Blocks shall be arranged to accommodate lots and building sites of the size and character required by these regulations and any applicable zoning resolution, to provide for adequate community facilities, and to regard the limitations and opportunities of topography.
(c) Irregularly-shaped blocks, those intended for cul-de-sacs and loop streets, and those containing interior parks or playgrounds may be approved by the Commission if properly designed and located.
(d) No block shall be longer than one thousand four hundred (1,400) feet nor less than six hundred (600) feet. The block shall normally accommodate two (2) tiers of lots and shall have a minimum width of two hundred fifty (250) feet, except where unusual topography or other extreme physical circumstances exist.
(e) Where blocks are more than nine hundred (900) feet in length, a crosswalk easement not less than ten (10) feet in width at or near the halfway point of the block may be required.
(f) Blocks intended for commercial and industrial subdivisions shall be designed specifically for such purposes and shall include adequate provisions for parking, loading, and delivery services. Such blocks shall not be less than two hundred fifty (250) feet in width nor less than one thousand feet in length.