The following zoning ordinance regulations follow a comprehensive plan in order to allow better circulation of pedestrian and vehicular traffic with minimum congestion; to provide adequate light and air; to avoid overpopulation or excessive crowding of land; to facilitate the provision of adequate transportation, water, sewerage, schools and parks; and to promote the general health and welfare of the community. Also a purpose of this article is to conserve the value of buildings and to encourage appropriate use of land.