(A) Private roadways.
(1) Minor subdivisions. Boone County hereby finds the unobstructed, safe and continuous access to lots for residential purposes is necessary and determines that is in the best interest of the county in the protection of the public health, safety and welfare to regulate the construction, improvement, extension, relocation, and use of private roads and easements providing access to existing and future lots.
(a) Private roadways may be constructed to serve lots in minor subdivisions. The owners of each lot parallel to the roadway shall own, as tenants in common, an undivided interest in the private roadway.
(b) Access. Minor subdivisions may utilize a private, shared driveway as an alternate to development of a public street. All residential lots utilizing a private access driveway for access shall have frontage on a public road. The minimum width of that frontage is 100 feet in width.
(c) Clear vision areas at intersections or private access driveways shall comply with the Boone County Highway Department Standards.
(d) Private access driveways will be constructed so as to protect against or minimize soil erosion and prevent damage to the lakes, streams, wetlands and the natural environment of the county.
(e) Private access driveways will be designed and constructed with adequate width, surface, and grade to ensure safe passage and maneuverability of private vehicles, police, fire, ambulance, and other safety vehicles.
(f) Private access driveways will be allowed to cross over a legal drain upon approval by the Boone County Drainage Board. No private access driveway will be able to run parallel within a legal drainage easement.
(g) All private access driveways will not be located in any floodplain areas, regulated drainage easements, utility easements and other such designed easements.
(h) Private access driveways will not adversely affect the long term development policies of the county.
(2) Major subdivisions. Private roadways are not permitted in any type of major subdivisions.
(B) Gravel roads. Public gravel roads, in general, will not be improved by the county in order to mitigate impacts resulting from increased population or subdivision.
(C) Abandonment. No public roadway shall be abandoned or vacated unless in accordance with state law.
(D) Lines of right-or-way. For the purposes of establishing lot lines, street right-of-way lines shall be considered as the front line of lots and tracts bordering the street.
(E) Street classifications. Streets in Boone County are classified as interstate, arterial, major collector, minor collector and local. For the purposes of subdivision development, local roads shall be further classified and defined as follows:
(1) Subcollector. Subcollectors operate as the principal traffic artery within subdivision development. Subcollectors commonly carry relatively high volumes and convey traffic from collectors and other county roads outside of the development. Subcollectors are designed to promote the free flow of traffic. Parking along a subcollector shall be prohibited and road cuts shall be minimized.
(2) Feeder. Feeders convey traffic from access streets to subcollectors, collectors and other county roads. Feeders commonly carry a relatively low volume of traffic. Feeders may be used for road frontage and access to lots.
(3) Access. Access streets convey traffic from the subdivision lot to feeders or subcollectors. Access streets commonly carry no through traffic and include short streets, often ending in a cul-de-sac. Access streets are designed to serve a limited number of dwellings or establishments.
(F) Considerations for street classification. In classification of streets, the following shall be considered: As noted in Table 4, APT shall be determined according to Trip Generation, developed by the Institute of Transportation Engineers. In the instance that a use is not indicated, the applicant shall either propose, to the satisfaction of the Director, a similar but indicated use, or provide sufficient private information regarding the use as to provide an accurate estimate of average daily traffic including but not limited to:
(1) Density and lot width;
(2) Abutting land use;
(3) Availability of off-street parking;
(4) Proximity of residential to commercial (or commercial to residential) development and other services; and
(5) Public service such as trash collection, snow removal and public safety.
Traffic Volume According to Street Classification | |
Class | ADT Range |
Access | 0 to 200 |
Feeder | 201 to 1,000 |
Subcollector | 1,001 to 3,000 |
Collector (minor or major) | 3,001 to more |
(G) Layout. The street layout shall provide adequate vehicular and pedestrian access to all lots and parcels of land within the subdivision and where streets cross other streets, jogs shall not be created. Streets shall conform to the following principles and standards.
(1) Proposed streets shall be adjusted to the contour of the land so as to produce usable lots and streets of reasonable gradient.
(2) Residential street systems may be designed to minimize through traffic movement, but certain proposed streets, where appropriate, shall be extended to the boundary line of the tract to be subdivided so as to provide for normal circulation of traffic within the vicinity.
(3) Wherever there exists a dedicated or platted portion of a street adjacent to the proposed subdivision, the remainder of the street to the prescribed width shall be platted within the proposed subdivision.
(4) Residential street patterns shall provide reasonably direct access to the primary circulation system.
(5) Local circulation systems and land development patterns shall not conflict with the efficiency of bordering thoroughfares.
(6) Widths of thoroughfares shall conform to the widths set forth in Appendix 2, Street Design Characteristics.
(7) The minimum right-of-way of residential streets or cul-de-sacs shall be 50 feet. All cul-de-sacs longer than 600 feet shall terminate in a right-of-way with a minimum diameter of 100 feet and minimum roadway diameter of 95 feet.
(8) The center lines of streets should intersect as nearly at right angles as possible.
(9) At intersections of streets, property line corners shall be rounded by arcs of at least 20 feet radii or by chords of the arcs.
(10) If the smaller angle of intersection of two streets is less than 60 degrees, the radius of the arc at the intersection of property lines shall be increased as deemed advisable by the APC.
(11) Intersections of more than two streets at one point shall be avoided.
(12) Street jogs with centerline off-sets of less than 125 feet shall not be permitted when intersecting an access or feeder road or 250 feet when intersecting a subcollector or collector road.
(13) Where parkways or special types of streets are involved, the APC may apply special standards to be followed in their design.
(14) Whenever the proposed subdivision contains or is adjacent to a railroad right-of-way, arterial, major collector or minor collector, frontage or access road to be built in such a manner as to provide adequate and safe access, parking and loading to the site while minimizing road cuts.
(15) A temporarily dead-ended street shall be permitted in any case in which a street is proposed to be and should logically be extended, but is not yet constructed. An adequate easement for a turn-around shall be provided for any such temporary dead-end street which extends 200 feet or more in length. The easement shall be automatically vacated to abutting property owners when the dead-ended street is legally extended.
(16) In subdivisions that adjoin or include existing streets that do not conform to the minimum right-of-way dimensions as established in Appendix 2, Street Design Characteristics, the subdivider shall dedicate additional width along either one or both sides, of the streets of inadequate width so as to bring them up to standards, provided the area to be used for widening is owned by the subdivider or under his or her control.
(17) Horizontal visibility on curved streets and vertical visibility on all streets must be maintained along the center line as follows:
(a) Arterials and major collectors: 500 feet;
(b) Minor collectors: 300 feet; and
(c) Local streets: 200 feet.
(18) Curvature measure along the center line shall have a minimum radius as follows:
(a) Arterials and major collectors: 500 feet;
(b) Minor collectors: 300 feet; and
(c) Local streets: 200 feet.
(19) Between reversed curves of arterials, major collectors and minor collectors, there shall be a tangent of not less than 100 feet and on local streets such tangent shall be not less than 40 feet.
(20) Maximum grades for streets shall be as follows:
(a) Arterials, major collectors and minor collectors: not greater than 6%.
(b) Local streets: not greater than 870.
(c) The minimum grade of any street gutter shall not be less than 0.57.
(H) Street names. No street names may be used which will duplicate, or be confused with, the names of any existing streets unless the proposed streets are the logical extension of continuation of, or obviously in alignment with an existing platted street, in which case the proposed streets shall bear the names of the existing streets. The APC shall have final authority to approve names for all streets.
(I) Subdivisions bordering existing streets. Whenever a proposed subdivision borders an existing street, the APC may require the reconstruction or widening of the street as a condition of plat approval. Additional dedication of right-of-way may also be required.
(J) Site lines, access, bridges and culverts.
(1) Site lines. The following paragraph shall be required as a provision of the restrictive covenants of all secondary plats to which they apply:
“No fence, wall, hedge, tree or shrub planting which obstructs sight lines and elevations between three and 12 feet above the street shall be placed or permitted to remain on any corner lot within the triangular area formed by the street right-of-way lines and a line connecting a point 40 feet from the intersection of the street lines, or in the case of a rounded property corner from the intersection of the street right-of-way lines extended.”
(2) Access. At the intersection of any proposed local street and arterial, major collector or minor collector, acceleration and deceleration lanes shall be provided.
(3) Bridges and culverts. All bridges and culverts shall be constructed in accordance with applicable engineering standards as approved by the Boone County Highway Department.
(K) Installation. Streets shall be completed to grades shown on plans, profiles and cross-sections, provided by the subdivider, and prepared by a registered professional engineer and approved by the APC.
(1) The streets shall be graded, surfaced and improved to the dimensions required by such plans, profiles and cross-sections and the work shall be performed in the manner prescribed in Standard Specifications for Road and Bridge Construction and Maintenance (current issue) of the State of Indiana Department of Transportation and construction standards of this chapter and the Boone County Highway Department. References in the following paragraphs refer to the INDOT Standard Specifications.
(2) The street pavement shall be of Portland cement concrete or a flexible asphalt concrete pavement in accordance with design standards noted in Appendix A, Street Design Characteristics. Acceptable pavement alternatives are also available in Appendix A. All concrete pavement and flexible asphalt pavement mix designs shall meet or exceed all minimum INDOT Standard Specifications. A gradation report of all materials used in the mix designs and the mix design shall be furnished to the Boone County Highway Department. Recycled asphalt pavement (RAP) shall not exceed 10% of base or binder mix designs. No RAF will be allowed in the asphalt surface mix design.
(3) No asphalt base, binder or surface layer shall be placed until air temperature is 45 degrees and rising as in accordance with INDOT standards and Boone County Highway Department requirements. An asphalt emulsion tack coat is required on the full face of any curb and in between the base or binder and surface layer. Before any surface layer can be applied, it should be cleaned to the approval of the Boone County Highway Inspector.
(4) The asphalt contractor shall have an adequate supply of equipment on the job site approved by the Highway Inspector.
(5) Compaction of all pavement shall be in accordance with INDOT Standards Specifications.
(6) All stone aggregates used shall meet or exceed INDOT Standard Specifications and shall be a Class A Type “O” aggregate. A gradation report of the material dated no more than five days prior to delivery of material to the subdivision shall be supplied to the Boone County Highway Department prior to placement of stone material. If the stone does not have enough moisture in it to get adequate compaction, then the contractor shall have a water truck available to apply a sufficient amount of water needed to obtain the required compaction. All stone bases shall be compacted by a minimum ten-ton vibratory roller. Each stone base shall be inspected by the Boone County Highway Inspector before the next course can be applied.
(7) Under drains shall be required under both sides of streets and shall be located as indicated in Appendix A, Street Design Characteristics, and shall discharge into a storm drainage system. A gradation report for stone or gravel shall be provided to the Boone County Highway Department and the Boone County Surveyor prior to placement of material.
Location | |
Location | |
Major collector, curb and gutter | |
Standard | 1 |
Full depth bituminous alternate | 2 |
Minor collector, curb and gutter | |
Standard | 3 |
Full depth bituminous alternate | 4 |
Subcollector | 5 |
Feeder | |
Typical | 6 |
Alternate with shoulder | 7 |
Access | |
Typical | 8 |
Alternate with reduced right-of-way | 9 |
(8) Subcollector streets for commercial or industrial development shall be required to meet all specifications for residential collector streets while feeder or access streets shall be required to meet all specifications for residential subcollector streets.
(9) Where an arterial, major collector or minor collector is located within a subdivision as established by this chapter, the subdivider shall construct the street pavement in accordance with Appendix A, Street Design Characteristics.
(10) Prior to placing the street surface, adequate drainage for the street shall be provided by the subdivider. Culvert drainage pipe, when required, shall be concrete pipe or a similar type not less than 12 inches in diameter approved by the APC. Upon the completion of the street improvements, plans and profiles as built shall be filed with the APC. Longitudinal sub-grade drainage shall be provided below the depth of the sub-grade.
(11) Before any performance bond covering a street installation is released, the APC, the appropriate legislative body or county’s Highway Superintendent may request that core borings of the street be done at the subdivider’s expense. Gores shall be sent to the county’s Highway Superintendent and/or an independent testing laboratory for analysis. The subdivider may request permission of the APC and the appropriate legislative body to delay the installation of the 1-1/2-inch surface layer of asphalt until the binder layer of asphalt has had a sufficient time period to prove its durability under the stress of heavy construction traffic. The subdivider shall be required to submit a separate performance bond to cover the cost of the installation of the 1-1/2-inch surface layer of asphalt.
(L) Block standards.
(1) Block length and width or acreage within bounding streets shall be such as to accommodate all requirements of this chapter in the District in which the subdivision is to be located, and to provide convenient access, circulation control and safety of traffic. Blocks that are unreasonably large or small shall not be approved.
(2) Blocks shall not exceed 1,200 feet in length. In the design of blocks longer than 800 feet, the APC may specify the provision of pedestrian crosswalks or interior trails near the center of the block, or wherever would be most useful to facilitate pedestrian circulation to a school, park, recreation area, shopping center or other significant neighborhood destination.
(M) Curbs and gutters. The APC shall require curb and gutter to be installed on each side of the street surface. The curb and gutter shall be constructed according to the following specifications.
(1) Curb and gutters shall be placed on a well compacted aggregate base that extends approximately one foot outside the back of the curb.
(2) All gutters and curbs shall be constructed in accordance with Appendix A, Street Design Characteristics.
(3) All materials in the curb mix shall meet or exceed INDOT Standard Specifications Class A Concrete and a gradation report for all materials shall be furnished to the Highway Inspector prior to installation.
(4) No concrete curb mix shall be placed below air temperatures of 40 degrees.
(N) Sidewalks.
(1) Sidewalks shall be required on both sides of any collector, subcollector, feeder or access street upon which development occurs. The Director, Plat Committee or APC may allow a minimum 5-foot wide asphalt trails as an alternate.
(2) Sidewalks shall be constructed of Class A Portland Cement Concrete in accordance with Appendix 2, Street Design Characteristics,
(3) When possible, trails should be provided within the subdivision and should complement the sidewalk system. Trails shall be comprised of asphalt and shall maintain a minimum width of five feet.
(O) Street signs. The subdivider shall provide the subdivision with standard county or town street signs at the intersection of all streets.
(1) Stop signs shall be constructed of 30-inch by 30-inch High Intensity 3M sheeting. Stop signs shall be mounted on flanged u-channel sign posts, shall weigh three pounds per foot and extend 12 feet in length.
(2) Speed limit signs shall be constructed on Engineer Grade 3M sheeting and be mounted on flanged u-channel sign posts which shall weigh three pounds per foot and extend 12 feet in length.
(3) All street name signs are to be constructed on 9-inch aluminum plate high intensity sheeting. Street signs shall be green with 6-inch white letters and a white border. All street signs are to be mounted on tubular sign posts, 12 feet in length.
(4) All mounting brackets shall be provided by the Highway Department.
(5) All street signs shall conform with the Indiana Manual on Traffic Control Devices Guide Signs for Conventional Roads.
(P) Street lights. Street lights may be required to be installed at intersections throughout the subdivision and the installations shall conform to the requirements of the public utility providing the lighting.
(Q) Rights-of-way.
(1) Permanent structures. No permanent decorative signs or permanent objects of any kind such as sprinkler heads or fencing of any kind shall be permitted within the public right-of-way.
(2) Trees and shrubs.
(a) Trees and shrubs shall be permitted in the public right-of-way in accordance with a landscape plan approved by the APC during the secondary plat process. The plan shall be developed by an urban forester, arborist or landscape architect. In development of any landscape plan that includes trees or shrubs in the public right-of-way, consideration shall be given to mature height and spread; potential damage to sidewalks, street under-drains, curbs and street pavements by root systems; maintenance requirements; tolerance to pruning; and adaptability to the specific street environment, including heat, glare, snow and salt. Tree selection shall consider vertical clearance of branches sufficient to allow adequate room visually and physically for vehicles passing underneath.
(b) Shrubs shall be low growing and salt tolerant.
(c) The location of trees and shrubs at intersections shall permit clear sight distance two feet to six feet above the street and 100 feet in any direction of an intersection.
(d) Vegetation shall be selected with consideration for low maintenance requirements and shall have a minimal amount of leaf and fruit litter. All vegetation and its continued maintenance shall be the responsibility of the homeowner or homeowners’ association.
(Ord. 98-26, passed 12-21-1998)