(A) General requirements.
(1) Frontage on improved roads. No subdivision shall be approved unless the area to be subdivided shall have frontage on and access from an existing street or:
(a) An existing state highway; or
(b) A street shown upon a plat approved by the Commission and recorded in the County Clerk’s office. Such street or highway shall be suitably improved as required by the highway rules, regulations, specifications or orders, or be secured by a performance bond required under these subdivision regulations, with the width and right-of-way required by these subdivision regulations.
(2) Grading and improvement plan. Roads shall be graded and improved and conform to the city construction standards and specifications and shall be approved as to design and specifications by the City Engineer, in accordance with the construction plans required to be submitted prior to final plat approval.
(3) Topography and arrangement.
(a) Roads shall be related appropriately to the topography. Local roads shall be curved wherever possible to avoid conformity of lot appearance. All streets shall be arranged so as to obtain as many as possible of the building sites at, or above, the grades of the streets. Grades of streets shall conform as closely as possible to the original topography. A combination of steep grades and curves shall be avoided. Specific standards are contained in the design standards of these subdivision regulations.
(b) All streets shall be properly integrated with the existing and proposed system of thoroughfares and dedicated rights-of-way.
(c) All thoroughfares shall be properly related to special traffic generators such as industries, business districts, schools, churches and shopping centers; to population densities; and to the pattern of existing and proposed land uses.
(d) Minor and local streets shall be laid out to conform as much as possible to the topography, to discourage use by through traffic, to permit efficient drainage and utility systems, and to require the minimum number of streets necessary to provide convenient and safe access to property.
(e) The rigid rectangular gridiron street pattern need not necessarily be adhered to, and the use of curvilinear streets, cul-de-sacs or V-shaped streets shall be encouraged where such use will result in a more desirable layout.
(f) 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 of the subdivision with the existing layout or the most advantageous future development of adjacent tracts.
(g) In business and industrial developments, the streets and other accessways shall be planned in connection with the grouping of buildings, location of rail facilities and the provision of alleys, truck loading and maneuvering areas, and walks and parking areas so as to minimize conflict of movement between the various types of traffic, including pedestrian.
(4) Blocks.
(a) Blocks shall have sufficient width to provide for two tiers of lots of appropriate depths. Exceptions to this prescribed block width shall be permitted in blocks adjacent to major streets, railroads or waterways.
(b) The lengths, width and shapes of blocks shall be such as are appropriate for the locality and the type of development contemplated, but block lengths in residential areas shall not exceed 2,200 feet or 12 times the minimum lot width required in the zoning district, nor be less than 400 feet in length. Wherever practicable, blocks along major arterials and collector streets shall be not less than 1,000 feet in length.
(c) In long blocks, the Commission may require the reservation of an easement through the block to accommodate utilities, drainage facilities or pedestrian traffic. Pedestrianways or crosswalks, not less than ten feet wide, may be required by the Commission through the center of blocks more than 800 feet long where deemed essential to provide circulation or access to schools, playgrounds, shopping centers, transportation or other community facilities. Blocks designed for industrial uses shall be of such length and width as may be determined suitable by the Commission for prospective use.
(5) Access to primary arterials. Where a subdivision borders on or contains an existing or proposed primary arterial, the Commission may require that access to such streets be limited by one of the following means:
(a) The subdivision of lots so as to back onto the primary arterial and front onto a parallel local street; no access shall be provided from the primary arterial, and screening shall be provided in a strip of land along the rear property line of such lots;
(b) A series of cul-de-sacs, V-shaped streets or short loops entered from and designed generally at right angles to such a parallel street, with the rear lines of their terminal lots backing onto the major arterial; and/or
(c) A marginal access or service road (separated from the primary arterial by a planning or grass strip and having access thereto at suitable points).
(6) Road names. The sketch plat as submitted shall not indicate any names upon proposed streets. The Commission shall approve the name of all roads at the time of preliminary approval. The local postmaster shall be consulted by the Commission prior to rendering its request to the Commission. Names shall be sufficiently different in sound and in spelling from other road names in the city so as not to cause confusion. A road which is or is planned as a continuation of an existing road shall bear the same name.
(7) Road regulatory signs. The applicant shall deposit with the city at the time of final subdivision approval the sum of $50 for each road sign required by the City Engineer at all road intersections. The city shall install all road signs before issuance of certificates of occupancy for any residence on the streets approved. Street name signs are to be placed at all intersections within or abutting the subdivision, the type and location of which to be approved by the City Engineer.
(8) Street lights. Installation of street lights shall be required in accordance with design and specification standards approved by the City Engineer.
(9) Reserve strips. The creation of reserve strips shall not be permitted adjacent to a proposed street in such a manner as to deny access from adjacent property to such street.
(10) Construction of roads and dead-end roads.
(a) Construction of roads. The arrangement of streets shall provide for the continuation of principal streets between adjacent properties when such continuation is necessary for convenient movement of traffic, effective fire protection or efficient provision of utilities. If the adjacent property is undeveloped and the street must be a dead-end street temporarily, the right-of-way shall be extended to the property line. A temporary T - or L- shaped turnabout shall be provided on all temporary dead-end streets, with the notation on the subdivision plat that land outside the normal street right-of-way shall revert to abuttors whenever the street is continued. The Commission may limit the length of temporary dead-end streets in accordance with the design standards of these subdivision regulations.
(b) Dead-end road (permanent). Where a road does not extend the boundary of the subdivision and its continuation is not required by the Commission for access to adjoining property, its terminus shall normally not be nearer to such boundary that 50 feet. However, the Commission may require the reservation of an appropriate easement to accommodate drainage facilities, pedestrian traffic or utilities. A cul-de-sac turnaround shall be provided at the end of a permanent dead-end street in accordance with city construction standards and specifications. For greater convenience to traffic and more effective police and fire protection, permanent dead-end streets shall, in general, be limited in length in accordance with the design standards of these subdivision regulations.
(B) Design standards.
(1) General. In order to provide for roads of suitable location, width and improvement to accommodate prospective traffic and afford satisfactory access to police, firefighting, snow removal, sanitation and road-maintenance equipment, and to coordinate roads so as to compose a convenient system and avoid undue hardships to adjoining properties, design standards for roads are hereby required. Road classification shall be determined by the Commission.
(2) Road surfacing and improvements. After sewer and water utilities have been installed by the developer, the applicant shall construct curbs and gutters and shall surface or cause to be surfaced roadways to the widths prescribed in these subdivision regulations. All local and minor streets shall be paved with a concrete pavement of a minimum thickness of seven inches or of asphaltic concrete or other material of equivalent quality and shall be provided with an adequate base as determined by accepted engineering practice. Such surfacing shall be of such character as is suitable for the expected traffic and in harmony with similar improvements in the surrounding areas. Adequate provision shall be made for culverts, drains and bridges. All road pavement, shoulders, drainage improvements and structures, curbs, turnarounds and sidewalks shall conform to all construction standards and specifications adopted by the Commission, City Engineer or city and shall be incorporated into the construction plans required to be submitted by the developer for plat approval.
(3) Excess right-of-way. Right-of-way widths in excess of the standards designated in these subdivision regulations shall be required whenever, due to topography, additional width is necessary to provide adequate earth slopes. Such slopes shall not be in excess of three to one.
(4) Railroads and limited access highways. Railroad rights-of-way and limited access highways where so located as to affect the subdivision of adjoining lands shall be treated as follows.
(a) In residential districts, a buffer strip at least 25 feet in depth in addition to the normal depth of the lot required in the district shall be provided adjacent to the railroad right-of-way or limited access highway. This strip shall be part of the platted lots and shall be designated on the plat: “This strip is reserved for screening. The placement of structure hereon is prohibited.”
(b) In districts zoned for business, commercial or industrial uses, the nearest street extending parallel or approximately parallel to the railroad shall, wherever practicable, be at a sufficient distance therefrom to ensure suitable depth for commercial or industrial sites.
(c) Streets parallel to the railroad when intersecting a street which crosses the railroad at grade shall, to the extent practicable, be at a distance of at least 150 feet from the railroad right-of-way. Such distance shall be determined with due consideration of the minimum distance required for future separation of grades by means of appropriate approach gradients.
(5) Intersections.
(a) Streets shall be laid out so as to intersect as nearly as possible at right angles. A proposed intersection of two new streets at an angle of less than 75 degrees shall not be acceptable. An oblique street should be curved approaching an intersection and should be approximately at right angles for at least 100 feet therefrom. Not more than two streets shall intersect at anyone point unless specifically approved by the Commission.
(b) Proposed new intersections along one side of an existing street shall, wherever practicable, coincide with any existing intersections on the opposite side of such street. Street jogs with centerline offsets of less than 150 feet shall not be permitted, except where the intersected street has separated dual drives without median breaks at either intersection. Where streets intersect major streets, their alignment shall be continuous. Intersections of major streets shall be at least 800 feet apart.
(c) Minimum curb radius at the intersection of two local streets shall be at least 20 feet; and minimum curb radius at an intersection involving a collector street shall be at least 25 feet. Alley intersections and abrupt changes in alignment within a block shall have the corners cut off in accordance with standard engineering practice to permit safe vehicular movement.
(d) Intersections shall be designed with a flat grade wherever practical. In hilly or rolling areas, at the approach to an intersection, a leveling area shall be provided having not greater than a 2% rate at a distance of 60 feet, measured from the nearest right-of-way line of the intersecting street.
(e) Where any street intersection will involve earth banks or existing vegetation inside any lot corner that would create a traffic hazard by limiting visibility, the developer shall cut such ground and/or vegetation (including trees) in connection with the grading of the public right-of-way to the extent deemed necessary to provide an adequate sight distance.
(f) The cross-slopes on all streets, including intersections, shall be 3% or less.
(6) Bridges. Bridges of primary benefit to the applicant, as determined by the Commission, shall be constructed at the full expense of the applicant without reimbursement from the city. The sharing expense for the construction of bridges not of primary benefit to the applicant as determined by the Commission, shall be fixed by special agreement between the city and the applicant. Such cost shall be charged to the applicant pro rata as the percentage of his or her land developed and so served.
(C) Road dedications and reservations.
(1) New perimeter streets. Street systems in new subdivisions shall be laid out so as to eliminate or avoid new perimeter half-streets. Where an existing half-street is adjacent to a new subdivision, the other half of the street shall be improved and dedicated by the subdivider. The Commission may authorize a new perimeter street where the subdivider improves and dedicates the entire required street right-of-way width within his own subdivision boundaries.
(2) Widening and realignment of existing roads. Where a subdivision borders an existing narrow road or when the comprehensive plan, or zoning setback regulations indicate plans for realignment or widening a road that would require use of some of the land in the subdivision, the applicant shall be required to improve and dedicate at his or her expense such areas for widening or realignment of such roads. Such frontage roads and streets shall be improved and dedicated by the applicant at his or her own expense to the full width as required by these subdivision regulations. Land reserved for any road purposes may not be counted in satisfying yard or area requirements of the zoning regulations whether the land is to be dedicated to the municipality fee simple or an easement is granted to the city.
(Ord. passed 2-2-2010)