(A) Access to roads.
(1) New lots. Any new lot approved under this chapter shall have adequate and safe permanent access to 1 of the following:
(a) A public road;
(b) A private road meeting the requirements of this section; or
(c) A driveway with a minimum cartway width of 12 feet within a right-of-way established on the record plat and at least 30 feet wide, provided no more than 2 dwellings have road access via the driveway; or,
(d) In the case of a business park, townhouse, apartment or mobile home park development, individual buildings may have vehicle access onto a parking court, provided the parking court has access to a public road or an approved private road.
(2) Emergency access. If doubt exists, the Subdivision Administrator may require an applicant to provide evidence that a new or extended road will be sufficient in width, surface, slope, height clearance, turning radius, weight limits and drainage to provide adequate access for fully loaded fire trucks and ambulances during normal weather conditions. A review by emergency service providers may be requested. However, the county does not accept responsibility to guarantee that such access will be possible.
(3) Existing private road. The following requirements shall apply if a new lot is proposed to have vehicle access using a private road that existed on July 1, 1997:
(a) The maintenance requirements of division (B) shall be met to the extent feasible.
(b) A legally established easement or right-of-way shall provide access by all affected property-owners. Along an existing private road, the easement or right-of-way shall have a minimum width of 30 feet along all property owned by the applicant.
(c) If 1 or more new lots are proposed along an existing private road that does not include at least 3 inches total depth of stone and/or other suitable surface and a width of 12 feet or 16 feet as required below, the following conditions shall be met:
1. Approval of the final plat shall be subject to improvement of the road to include a minimum depth of 3 inches of appropriate stone or other county-approved surface across a minimum cartway width of 12 feet if between 1 and 10 new dwellings will be served by the road; or a minimum cartway width of 16 feet if 11 or more new dwelling units will be served.
2. The width and depth shall be provided along the entire portion of the private road from the driveways of the new lots to a public road.
3. The road improvement shall be complete prior to issuance of building permits for the new lots.
(d) The applicant shall show that the road will meet the emergency access standards described in subsection (2) above, after any improvements that the applicant may agree to make.
(4) New or extended private roads. For new or extended private roads, see width requirements in division (G).
(B) Maintenance and ownership of private roads.
(1) The ownership and entity responsible for maintenance of a private road shall be identified on the final plat. The documentation accompanying a final plat must include legally binding language stating who is to be responsible for the improvement and maintenance of any road or parking court not offered for dedication.
(2) The developer shall be responsible for maintenance of a road until it is dedicated to the county or a property-owners association.
(3) If a property owners association will own and maintain the private road, the applicant shall submit proposed covenants that will govern the association to the county for review and approval as part of the preliminary plat application.
(4) If a private road is not owned by a property owners association, the owners of a parent lot and any new lots shall be bound by a legal document approved by the county that provides for periodic payments and maintenance of a private road.
(5) Legal responsibility for maintenance of a private road shall be enforceable by any affected property-owner, with the county not accepting responsibilities for enforcement.
(C) Road continuations.
(1) Stub roads. If a road is proposed to be a public road, then where deemed necessary by the Planning Commission for efficient movement of traffic, a subdivision shall include the extension of a proposed road right-of-way or emergency vehicle accessway to the boundary line of the tract to provide for an eventual extension into the adjacent tract for efficient circulation of traffic throughout the area.
(2) Widening. Where a subdivision abuts or contains an existing road of inadequate cartway, shoulder or right-of-way width, additional right-of-way, shoulder and/or cartway width may be required by the Planning Commission as necessary for public safety, stormwater control and potential utility extensions.
(3) If a property being subdivided fronts on a county or town road and the road right-of-way adjoining the properties has not previously been conveyed to the county or town, the applicant for the subdivision shall convey to the jurisdiction sufficient right-of-way measured from the centerline of the road to match the prevailing width of the road along its entire length.
(D) Intersections.
(1) Centerline of roads. The centerlines of roads shall intersect at right angles where physically feasible. If right angles are not feasible, the intersection shall be at as nearly a right angle as possible, with an absolute minimum inside angle of 68 degrees.
(2) Alignment of road intersections. A maximum of 2 roads shall intersect at 1 point.
(a) Where a proposed road or business driveway intersects an existing perpendicular road, the proposed road or business driveway shall be aligned with any road intersecting on the other side of the perpendicular road, unless the Planning Commission or State Highway Administration determine that the alignment is not reasonable or feasible.
(b) If a proposed road cannot intersect at the same location as a road on the other side of the perpendicular road, then the proposed road shall be offset by a minimum of 150 feet from the nearest intersection of roads, where physically feasible.
(3) Two or more roads. All approaches to an intersection of 2 or more roads shall have a leveling area not greater than 8% grade for a minimum distance of 20 feet, measured from the nearest edge of cartway of the intersecting road.
(4) Edge of roadways. At road intersections, the edge of the road cartway shall be rounded by arcs with the radii listed below.
Highest Type of Road Involved | Minimum Radius of Arc at Intersection of Cartway Edge |
Arterial road or commercial/industrial road | 30 |
Other road | 20 |
(E) Access management. The Planning Commission may require 1 or more of the following methods of layout and site design if it determines the methods will be reasonable, feasible and necessary to avoid increased traffic congestion and improve traffic safety on public roads. The Commission's decision to use 1 or more of the following methods will be based on recommendations of the County Engineer, recommendations of the Subdivision Administrator, comments from or requirements of the State Highway Administration and professional traffic studies that have been submitted.
(1) The use of a marginal access or “frontage” road or access only onto side or interior roads, to collect traffic from numerous driveways and direct it to a select few number of entrances to the public road;
(2) The minimization of the number and length of driveway cuts or road intersections onto a public road, which may include requiring the use of shared driveways between adjacent uses or lots;
(3) The restriction of ingress and egress involving left-hand turns onto or off of the public road;
(4) The prohibition of driveways from individual dwellings entering directly onto an arterial road; and/or
(5) Where individual driveways are proposed to enter onto an arterial road, or where driveways for nonresidential use are proposed to enter onto any public road, sufficient turn-around space shall be provided on the lot for vehicles so they do not need to back onto the road.
(F) New public roads or public road extensions.
(1) A new road or road extension that is intended to be dedicated to the county shall meet all requirements of the county roads ordinance, as amended, prior to acceptance by the county, in addition to requirements of this section.
(2) A new road or road extension that is intended to be dedicated to the State Highways Administration shall meet all requirements of such agency.
(G) Private road design and construction standards. (See the definition of “road” in § 159.016). Any new road or road extension that is not intended to be dedicated to the state or the county shall meet the following requirements:
(1) Right-of-way width.
(a) A new or extension of a private road shall have a minimum right-of-way width of 50 feet, except such minimum width shall be 30 feet for a segment of a road that will clearly serve a maximum total of 10 or fewer dwelling units. (Note: as of 1996, a road is required to have a minimum right-of-way width of 50 feet to be eligible for dedication.) The road right-of-way may also be used for utilities.
(b) An additional construction easement shall be established if the construction of the road will require grading beyond the right-of-way width.
(c) Any newly established right-of-way line shall be maintained at a minimum distance of 5 feet from the cartway, including around any turn lanes, cul-de-sacs and intersections.
(d) If an extended or new private road is proposed within an existing right-of-way that does not comply with these minimum width standards, the extension or new road shall be approved only if a waiver is granted in accordance with this chapter. In reviewing the waiver application, the Planning Commission shall consider the comments of the Subdivision Administrator and the County Engineer.
(2) Cartway width. A new or extended private road shall be constructed with the following minimum widths, based upon the total number of dwelling units that the Planning Commission determines could eventually be served by such road:
(a) In a portion of the county that is not regulated by a zoning ordinance, all lots shall be considered commercial or industrial lots for the purposes of these road width requirements, unless deed restrictions will prohibit principal commercial and industrial uses on all new lots. Home occupation businesses that are accessory to a dwelling may be permitted.
(b) If the road could eventually serve 20 or more dwelling units, or 2 or more commercial or industrial lots, then a minimum cartway width of 18 feet shall be required, with 2 feet wide shoulders on each side.
(c) If the road could eventually serve only 6 to 19 dwelling units, then a minimum cartway width of 16 feet shall be required, with 1 foot wide shoulders on each side.
(d) If the road could eventually serve only 3 to 5 dwelling units, then a minimum cartway width of 12 feet shall be required, with no shoulders.
(e) If a cartway serves only 1 or 2 residential lots or dwelling units or a single commercial or industrial lot, it shall be considered to be a driveway, not a road. When a third residential or second commercial or industrial lot is added, the subdivider shall upgrade the driveway to minimum private road standards for the entire length of the driveway to the nearest intersecting road.
(f) If a road will need to accommodate on-street parking, then the minimum shoulder width shall be increased to a total of 8 feet on each side that parking is to be permitted. The Planning Commission may also require additional shoulder widths where necessary for public safety, such as around a sharp curve.
(3) Road construction standards. All road pavements shall consist of the following construction, unless the following standard may be revised by the Planning Commission by resolution, and except as provided in subsection (G)(6):
(a) Stone. All roads shall be constructed on a rolled and compacted subgrade free of organic matter. A well-graded crushed stone aggregate, or other appropriate stone pre-approved by the County Engineer, shall be used. The stone shall be placed and rolled in a moist condition so that fines remain mixed with the more coarse material. The gravel surface shall be smooth, uniform and tightly packed to result in a minimum 6 inches of depth, laid in 2 courses of 3 inches each. The Planning Commission may approve alternate road surfaces under § 159.006, such as reducing requirements if a stone subsurface is present.
(b) Paving/tar and chip. Any segment of a road that will serve traffic from 20 or more dwelling units, or 2 or more commercial or industrial lots, or dwellings at an average density of 3 or more dwelling units per acre shall also be paved with asphalt or tar and chip. The roads shall be constructed in the same manner as described in subsection (a) above. Then, 1 of the following methods shall be used:
1. A plant-mixed bituminous material rolled smooth to a depth of at least 2 inches shall be applied to a well drained base; or
2. Triple coat tar and chip surface as follows: first, suitable stone shall be spread, rolled and compacted; then emulsified asphalt shall be applied; then additional suitable stone shall be spread, rolled and compacted; then emulsified asphalt shall be applied; then additional suitable stone shall be applied.
(c) Shoulders. Required shoulders shall be constructed of a minimum of 3 inches of crusher run stone, unless the Planning Commission determines that an acceptable stone sub-surface is present.
(d) Multiple subdivisions along a road. The following provisions apply to private roads and private road extensions built after July 1, 1997.
1. If a private road is built as part of 1 subdivision, and then a second subdivision is submitted that will use the same private road, and the addition of the second subdivision would cause the road to be required to be improved to a higher standard under this division (G), then the applicant for the second subdivision shall be required to improve the entire length of the private road to the higher standard.
2. If an applicant would be required by this subsection (e) to make unreasonable improvements considering the number of proposed lots, or cannot gain permission to make improvements along a certain road segment, then the Planning Commission may grant a modification under § 159.006. For example, the Planning Commission may permit an applicant to only be responsible for improvements of road frontage along his/her subdivision, as opposed to the entire length of road that serves traffic from his/her subdivision.
(4) Road slopes.
(a) Proposed roads shall be adjusted to the contour of the land to produce usable lots and reasonably sloped roads, while minimizing grading.
(b) A maximum slope of 12%shall apply to any private road, except: a maximum slope of 14% shall be permitted for a road that will eventually serve a total maximum of only 10 dwelling units, provided that all segments of such road with a slope greater than 12% are paved with asphalt or triple coat tar and chip, as specified in subsection (e) above.
(c) If road construction plans indicate that the slope of a proposed road is 10% or greater, “as built” measurements shall be submitted with verification from a licensed engineer to confirm that the built grade of the road does not exceed the maximum allowed slope. The as-built verification shall be submitted prior to release of improvement bonds.
(5) Radii and sight distance.
(a) New or extended private roads in any subdivision that could eventually serve 40 or more dwelling units shall adhere to the standards established in the AASHTO's latest publication of Geometric Design of Highways and Streets. All roads shall be designed to meet a minimum design speed of 20 mph or greater and all roads shall be posted with the speed limit of design.
(b) New or extended private roads in any subdivision that could eventually serve up to a maximum of 39 dwelling units shall adhere to the standards established in the AASHTO'S latest publication of Geometric Design of Very Low-Volume Local Roads (ADT < 400). All roads shall be designed to meet a minimum design speed of 15 mph or greater and all such roads shall be posted with the speed limit of design.
(6) Roads serving over 100 dwelling units. A new or extended segment of a road that provides the primary means of access for 100 or more dwelling units shall be built to the same minimum cartway width, cartway construction, cartway slope and right-of-way width requirements as would apply to a county road, regardless of whether the road would be public or private.
(7) Vertical curves. New private roads shall have minimum vertical curves as specified in AASHTO standards for geometric design of highways and streets.
(H) Additional standards for public and private roads.
(1) Roads shall be graded, improved and surfaced to the grades and dimensions shown on plans approved by the county.
(2) The finished road surface shall be crowned or superelevated to provide proper drainage.
(3) Any cut, fill or grading adjacent to roads shall result in stable slopes considering the material involved, and that are protected against erosion. All trenches shall be properly filled and compacted.
(I) Sight distance.
(1) At any intersection with a private road of another private road(s), or the intersection of a private road with a driveway serving 2 or more principal commercial or industrial uses, a clear sight triangle shall be provided as follows:
(a) At the intersection of 2 or more private roads where any of the intersecting roads are designed to serve 40 or more dwelling units, the sight triangle shall adhere to the standards established in the AASHTO's latest publication of Geometric Design of Highways and Streets.
(b) At the intersection of 2 more private roads, where all of the intersecting roads are designed to serve up to a maximum of 39 dwelling units, the sight triangle shall adhere to the standards established in the AASHTO's latest publication of Geometric Design of Very Low-Volume Local Roads (ADT <400).
(2) At any intersection of a private road with a public county road or the intersection of a public county road with a driveway serving a principal commercial or industrial use, the intersection shall comply with the County Entrance Requirements.
(3) At any intersection of a private road with a public state road or the intersection of a public state road with a driveway serving a principal commercial or industrial use The intersection shall comply with the State Highway Entrance Requirements.
(J) Alternative access; turnarounds.
(1) Where feasible and reasonable, the Planning Commission may require that a development proposed to be served by a dead-end road longer than 1,500 feet shall include an internal loop in the road, a second entrance point to an exterior road and/or an entryway limited to access by emergency vehicles. The Planning Commission may also require that a subdivision include appropriate road improvements or alternative access to prevent homes from being inaccessible by vehicles during flood conditions.
(2) Appropriate turnarounds shall be provided at the end of any road. If a road serves 10 or less dwelling units, it may be served with a hammerhead turnaround designed to comply with either of turnaround designs shown below.
Figure 1. Turnaround Designs
(3) Once a dead-end portion of a road serves more than 10 dwelling units, it shall be provided with a cul-de-sac turnaround. Private cul-de-sac roads must be provided with a turn-around with a minimum cartway radius of 25 feet to the edge of the cartway. If the private cul-de-sac turnaround area has a center island, the paved travel lane shall have a minimum width of 20 feet. A cul-de-sac on a public road shall meet the county roads ordinance.
(4) The circular cartway of the cul-de-sac shall be connected to the approach paving by an arc having a radius of not less than 20 feet.
(5) The Planning Commission may permit acceptable alternative turn-around designs, including a turn-arounds of acceptable radii incorporated into a parking court or a landscaped island within a cul-de-sac.
(6) Temporary stub roads shall be required to include at least a temporary turnaround, if the stub would be longer than 150 feet or serve 4 or more dwellings or lots.
(7) The maximum cross slope on the circular part of a cul-de-sac shall be 7%.
(K) Modifications of road requirements. Section 159.006 provides the Planning Commission with the authority to grant modifications and exceptions to the requirements of this chapter.
(1) In addition to those standards, the Planning Commission may also grant modifications and exceptions to the road requirements of this chapter if:
(a) The required road improvements would have severe negative impacts upon the scenic character and natural resources of an area;
(b) The required road improvements would provide little benefit because a relatively short segment of road would be improved at the end of a long segment of road built to a much lower standard, and/or
(c) The required road improvements would represent an unreasonable hardship considering the expense of the improvements compared to the number of lots that would be developed.
(2) The Planning Commission may also permit road improvements to be completed in logical phases that are tied to specified phases of construction of buildings or sale of lots.
(L) Right-of-way reservation for proposed roads.
(1) When land in a subdivision is within the area of a future county or state road right-of-way which is proposed in the Comprehensive Plan or in the county's or state's capital program, the county may require that the land be reserved.
(2) The following conditions apply to land reserved pursuant to this section:
(a) The subdivision shall be designed so that the reserved land will be available for purchase by the county or state.
(b) No reservation shall continue for longer than 3 years from the date of recordation of the plat except with written approval of all legal and equitable owners of the property.
(c) The period of time for which the land is reserved shall be specified on the recorded plat.
(d) The reserved land may be included within the area of lots in a subdivision as long as that area is not used to satisfy minimum lot size or lot width requirements and is not used for buildings.
(Ord. —, passed 6-24-1997; Am. Ord. —, passed 7-13-1999; Am. Ord. —, passed 3-29-2005; Am. Res. 2010-5, passed 5-25-2010)