Each of the figures of every such number or numbers on any residence or apartment building shall be not less than three inches in length, and on any store or place of business not less than six inches in length. All numbers shall be placed in conspicuous place on or near the entrance or entrances to the building to which they are to be attached and on or near the lot line abutting the alley servicing the building. On all places of business where awnings are used on the street level story of the building, such numbers shall also be displayed in a conspicuous place on such awnings. It is hereby made the duty of the owner, agent or person in possession of any building in the city to number it in the manner herein provided. The streets and other public ways and parts thereof and parcels of real estate which the city council designates by ordinance as parts of the arterial highway system of the city shall constitute said system.
Ordinances specifying the arterial highway system are on file in the city clerk's office.
This provision shall apply to areas of the city where the contiguous land is already laid out on the basis aforesaid and also to areas where the contiguous land is not subdivided. In areas where the contiguous land has been previously subdivided on some basis of arrangement of public streets, either with reference to location or width, other than as specified above, the streets to be laid out shall conform in location, direction and width with those existing in such contiguous land. Whenever land is subdivided within the corporate limits of the city there shall also be laid out public alleys of a minimum width of 16 feet in the rear of all lots in such subdivisions. Street grades shall be established along the curb lines of the streets and shall run in a straight line from the established grade at any street intersection to the established grade at the intersection of the next street thereto, or to any established street grade between the intersections of such streets. All ordinances fixing the grades of streets in the city shall be referred to the commissioner of sewers, and shall be passed by the city council only upon the recommendation of said commissioner.