Blocks shall not normally exceed fifteen hundred feet in length between street lines; except in hillside developments or where subdivisions containing parcels of one-half acre or larger justify or require a variation from this requirement. In any block over nine hundred feet in length there shall be a crosswalk or pedestrian way in accordance with Section 20.32.240. (Ord. 1046 NCS §1 (part), 1972; prior code §22.7.1100.)