The zoning regulations and districts as herein established have been in accordance with a comprehensive plan and are designed: to lesson congestion in the streets; to secure safety from fire, panic and other dangers; to promote health and general welfare; to provide adequate light and air; to prevent the overcrowding of land; to regulate signs; to avoid undue concentrations of population; and to facilitate the adequate provision of transportation, water, sewers, schools, parks and other public improvements. The regulations have also been made with reasonable consideration, among other things, to the character of the district and its peculiar suitability for particular uses. These regulations are adopted with a view to conserving the value of buildings and encouraging the most appropriate use of land throughout the city.