Page 1 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions The following general principles of design and requirements for the layout of subdivisions shall apply to subdivisions platted within the City and may be applied to subdivisions platted within the extraterritorial plat approval jurisdiction of the City. (1) GENERAL. (a) The subdivision layout shall conform to the Official Map. 1. Whenever a tract to be subdivided embraces any part of a highway, thoroughfare or parkway, so designated on said Official Map, such part of such public way shall be platted by the subdivider in the location and at the width indicated on the Official Map, except as otherwise directed by the Commission. 2. Where a proposed park or other recreational area, school site or other public ground shown on the Official Map is located in whole or in part within the proposed subdivision, such proposed public ground or park shall be either dedicated to the public or reserved for acquisition by the City; provided, in the event of such reservation for acquisition by the City, the City shall undertake proceedings to acquire such area not later than 3 years from the date of the issuance of the first building permit for construction in such subdivision, and if the City shall not have undertaken such proceedings within such period, the subdivider shall, at the expiration of such period, be relieved of any obligation to further reserve such area for such public purposes. 3. Where held appropriate by the Commission, open spaces, suitably located and of adequate size for parks, playgrounds or other recreational purposes for local or neighborhood use, shall be provided for under §23.08 in the proposed subdivision, even though these areas are not specifically shown on the Official Map. 4. No land shall be subdivided for residential use which is determined by the Plan Commission to be unsuitable for such use by reason of flooding or bad drainage, adverse earth or rock formation, topography, or any other feature Page 2 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions likely to be harmful to the health, safety or welfare of the future residents in the proposed subdivision of the City. (2) STREET AND BLOCK LAYOUT. (a) Streets. The street layout of the subdivision shall be in general conformity with a plan for the most advantageous development of adjoining areas and the entire neighborhood. 1. Where appropriate to the design, proposed streets shall be continuous and in alignment with existing, planned or platted streets with which they are to connect. 2. Proposed streets shall be extended to the boundary lines of the tract to be subdivided, unless prevented by topography or other physical conditions or unless, in the opinion of the Commission, such extension is not necessary or desirable for the coordination of the layout or the most advantageous future development of adjacent tracts. Dead- end streets of a length of not over 500' will be approved where, in the opinion of the Commission, they are appropriate for the type of development contemplated. 3. Proposed streets shall intersect one another as nearly at right angles as topography and other limiting factors of good design permit. 4. Wherever there exists adjacent to the tract to be subdivided a dedicated or platted and recorded half-width street or alley, the other half width of such street or alley shall be platted. 5. Alleys shall be platted in all business districts. To provide safe access to residential lots fronting on primary thoroughfares designated as limited access on the Thoroughfare Plan or by other governing bodies, alleys may be required in the rear of such lots or frontage streets required in front thereof. Alleys will not be approved in other locations in residence districts, unless required by unusual topography or other exceptional conditions. Dead- end alleys are prohibited except under unusual circumstances. Page 3 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions 6. Lands abutting highways or principal thoroughfares should be platted with the view of making the lots, if for residential use, desirable for such use by cushioning the impact of heavy traffic on such traffic ways; and with the view also of minimizing interference with traffic on such traffic ways as well as the accident hazard. This may be accomplished in several ways: a. By platting the lots abutting such traffic ways at very generous depth; and by providing vehicular access to them by means of either alleys in the rear or frontage streets next to the highway and connected therewith at intervals not less than every 1,000'. b. Another more desirable and usually more economical method consists of fronting the lots on a minor street paralleling the highway at a distance of a generous lot depth. Private driveways in this case would, of course, connect with such minor street. c. Selection, in a specific case, among the foregoing or other methods for accomplishing the purposes in view, must necessarily be made in consideration of topography and other physical conditions, the character of existing and contemplated developments and other pertinent factors that apply in each case. 7. Subdivisions abutting a stream, river, or lake are required by state law to provide roads at least 60' wide providing access to the low water mark so that there will be roads at not more than ½-mile intervals as measured along the stream or lake shore unless topography and ground conditions do not permit. (b) Blocks. 1. In general, blocks shall be planned to provide 2 tiers of lots that conform to the yard requirements of the Zoning Page 4 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions Code, but irregularly shaped blocks indented by cul-de-sacs will be acceptable when properly designed with relation to the overall plan. 2. The lengths of blocks shall be such as, in the opinion of the Commission, are appropriate for the locality and the type of development contemplated, but shall not exceed 1,200'. 3. In any block over 900' in length the Commission may require that a crosswalk or pedestrian way, not less than 10' wide, be provided near the center and entirely across such block. 4. The number of intersecting streets along highways, thoroughfares and parkways shall be held to a minimum. Wherever practicable, blocks along such traffic ways shall be not less than 1,000' in length. 5. Blocks intended wholly or partially for industrial or commercial use shall be reserved specifically for such purposes, with adequate space available for off street parking and loading purposes, as required by the Zoning Code. (3) MINIMUM RIGHT-OF-WAY WIDTHS OF STREETS, ALLEYS AND EASEMENTS FOR UTILITIES. (a) Highways, Primary Thoroughfares and Parkways. Specified in the official Thoroughfare Plan; not less than 80' wide in any case; provided dedication shall not be required of any width in excess of 100', the City to compensate the party entitled thereto, by purchase or in eminent domain proceedings, for any such excess so required. (b) Secondary Thoroughfares. Specified in the official Thoroughfare Plan; (not less than 70' wide in any case). (c) Collector Streets. 70'. (d) Local and Dead-End Streets. 60'. All dead-end streets shall terminate in a circular turn-around having a minimum right-of-way diameter of 120', Page 5 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions unless the Commission approves or suggests a "T" or "Y" shaped paved space in place of the required turning circle. (e) Frontage Streets. 40'. (f) Alleys. 20'. (g) Easements. Easements across lots or centered on rear or side lot lines shall be provided for utilities where necessary and shall be at least 10' wide. These easements permit the utilities to extend their services within this area, but do not prohibit the individual owner from landscaping, building or developing this area, unless specifically mentioned on the final plat or in the individual easement agreements. (4) ROADWAY WIDTHS, FACE TO FACE OF CURB. Required to be installed, with apportionment, if any, of expense therefor between the subdivider and the City to be determined by the Common Council at the time of final plat approval. Such widths shall be as follows: (a) Highways, Primary Thoroughfares and Parkways. As specified in the official thoroughfare plan (not less than 38' in any case). (b) Secondary Thoroughfares. As specified in the official thoroughfare plan (not less than 38' in any case). (c) Collector Streets. 38'. (d) Local and Dead-End Streets. (Am. #36-87) (Am. #28-00) 36', except that the Common Council, after review and report by the Plan Commission, Department of Public Works and Police and Fire Departments, may approve a width less than 36' but not less than 32' if the Council determines the different width will promote traffic and pedestrian safety, reduce roadway maintenance costs and improve the aesthetic or environmental impact of the roadway. The pavement of a turning circle at the end of a dead-end street shall have a minimum outside diameter of 90'. A "T" or "Y" shaped paved space, when approved by the Commission in place of a turning circle, shall have a minimum outside dimension of 90', shall be at least 30' wide in the "T" or "Y" and shall be flared by a minimum radii of 20'. (e) Frontage Streets. 30'. Page 6 of 8 CHAPTER 23 Subdivision and Platting 23.06 Principles of Design and Requirements for the Layout of Subdivisions (f) Alleys.