(A) General Criteria And Standards: The current edition of "Transportation And Land Development" by the Institute of Transportation Engineers is hereby incorporated into this section and made part hereof by this reference in order to provide direction as to the criteria which should enter into the selection of the design standards for all improvements.
1. All improvements required by this section shall be constructed in accordance with the standards herein and in accordance with the latest edition of the following Illinois department of transportation specifications:
a. "Standard Specifications For Road And Bridge Construction".
b. "Standard Specifications For Traffic Control Items".
c. "Manual On Uniform Traffic Control Devices For Streets And Highways".
d. "Highway Standards".
2. Convenient access to all property within the subdivision shall be afforded by either a dedicated public street or a private street or private access connecting with a public or private street. Public streets will usually be required in all subdivisions over ten (10) lots in size. Private streets may be considered by the plan commission depending on site suitability, provided that a binding agreement contained in the plat or other recorded or registered document shall assure the continued existence and maintenance of said street or access.
3. The arrangement, character, extent, width, grade and location of all streets shall conform to the Barrington Hills Road Network Map and shall be considered by the Plan Commission in relation to: existing and planned streets; reasonable circulation of traffic within the development; topography; storm water drainage; public convenience and safety; and their appropriate relationship to uses in the area to be served.
a. The type of street cross-section selected for each improvement required by this Section shall depend on the site conditions identified in the preliminary analysis and inventory prepared by the applicant and shall conform to Village approved design standards on file with the Village Clerk. A residential street cross-section may be used to limit the extent of disturbance on forested areas or where continuous ditches would be subject to erosion. Either a residential or rural street cross-section may be used in areas that can accommodate such improvements. Intermingling the two (2) types of street cross-sections in a start-and-stop fashion is prohibited.
b. A residential street cross-section shall consist of a paved surface with a curb and gutter section and a four foot (4') shoulder along each side. The shoulder shall slope toward the curb in cut sections and away from the curb in fill sections. Storm sewers shall be utilized to provide drainage.
c. A rural street cross-section shall consist of a paved surface with two foot (2') shoulders and a drainage ditch along each side.
d. All curb and gutter systems required by this Section shall be constructed in accordance with the residential street cross- section, rural street cross-section and combination curb and gutter cross-section standards adopted by the Board of Trustees and on file with the Village Clerk.
4. Minor streets shall be so aligned that their use by through traffic shall be discouraged.
5. Where, in the opinion of the Plan Commission, it is desirable to provide for street access to adjoining property, the proposed streets shall be extended by dedication to the boundary of such property.
6. Where deemed necessary for the purpose of providing adequate protection of residential properties and to afford separation of through and local traffic, the Plan Commission may recommend access streets be required to service areas fronting on major streets.
7. Proposed streets which are obviously in alignment or continuation of existing streets already named shall bear the name of such existing streets whether in the Village or in unincorporated areas. In no case shall the names for proposed streets duplicate existing street names, irrespective of the use of a suffix (such as street, road, boulevard, drive, place or court, etc.) or an abbreviation thereof. Street names shall be approved by the Plan Commission which shall keep a list of all street names in the Village.
8. No permanent building or structure or permanent improvement of any type shall be erected within the extension of street rights of way indicated on the Official Map of the Village.
(B) Right of Way:
1. The minimum width of right of way of any classification of street shall be as follows:
Public | |
Regional highway | 120' |
Area highway | 100' |
Collector | 80' |
Minor | 66' |
Min. cul-de-sac radius | 70' |
Private | |
Minor | 50 or 66' |
Min. cul-de-sac radius | 50', 60' or 70' |
2. When any subdivision or part of a subdivision is adjacent to only one side of an existing right of way, which is less than the required width, the subdivider shall dedicate additional right of way to meet the requirement in accordance with this regulation. Half-streets in new subdivisions are not permitted.
(C) Block Standards:
1. Block lengths and widths shall be coordinated with the development of the land and shall be provided in a manner that will allow proper traffic flow including fire fighting equipment and pedestrian use; and pedestrian accessways within the blocks to schools, parks or other destinations may be required by the Plan Commission.
2. A subdivision containing interior open space, parks, playgrounds or school sites, will be acceptable when such plans include adequate rights of way for pedestrian access to the interior open space. Such developments shall provide acceptable agreements as to development and maintenance of these areas.
(D) Public Street Design Standards:
1. Street Grades: The grades of collector streets shall not exceed six percent (6%). The grades for minor streets shall not exceed ten percent (10%). In no case shall the grade of any street be less than four-tenths of one percent (0.4%).
2. Vertical Alignment: The vertical curves of collector and larger streets shall not be less than two hundred feet (200') in length. The vertical curves for minor streets shall be not less than one hundred feet (100') in length. Exception to the above minimums may be made at intersections where the length of vertical curves shall be no less than fifty feet (50'). In no case shall stopping sight distance be less than required for a thirty (30) mile per hour design speed.
3. Horizontal Alignment: The minimum radius of center line horizontal curvature shall be as follows:
Collector streets | 300' |
Minor streets | 150' |
Angles on the center line of a street are not permitted. Reverse curves are allowed provided a minimum of one hundred feet (100') of tangent is introduced between the curves.
4. Intersections:
a. Center line: Streets shall be laid out to intersect at right angles whenever possible. Two (2) streets shall not intersect at an angle of less than seventy degrees (70o).
Streets with center line offsets of less than one hundred twenty five feet (125') will not be permitted.
b. Pavement Radii: Pavement radii at intersections shall not be less than the following when measured to the edge of street surface:
Residential | 25' |
Commercial | 40' |
c. Right-of-Way Radii: Right-of-way radii at intersections shall not be less than the following:
Residential | 30' |
Commercial | 40' |
d. Sight Distance: All intersections shall provide a minimum of two hundred feet (200') of horizontal sight distance on all quadrants. Banks and natural growth shall be removed as necessary to meet this requirement.
5. Surface Widths: Streets shall be improved to the following surface width according to classification:
Street
Classification | Surface Width |
Regional highways | * |
Area highways | * |
Collector streets | 24' |
Minor streets | 20' |
Alleys | 16' |
Commercial and industrial streets | 36' |
*As determined in conjunction with other government bodies and through the use of projected traffic counts.
6. Surface Crown: The surface of all roadways shall have a uniform slope from the center line to the edge of pavement of two one-hundredths feet (0.02') per foot.
7. Surface Material: Streets shall be improved with a surface material of Bituminous Concrete Surface Course Class I of the following minimum thicknesses:
on BAM base course - 2 inches
on granular base course - 21/2 inches
8. Base Course Material: Base course material shall be either crushed gravel, crushed stone or bituminous aggregate mixture (BAM). Minimum allowable thickness for the aggregate base course will be ten inches (10") and for the BAM six inches (6"). Minimum Marshall Stability for the BAM shall be fifteen hundred (1,500) pounds. Base course material will be placed to a width two feet (2') wider than the surface of the street.
In no instance may base course material be placed on a soft subgrade. If a soft subgrade is encountered, it shall be removed to stable material. Backfill material will consist of earthen material with an adequate supporting value or of granular material.
9. Pavement Structure Design: All pavement structures shall be designed in accordance with the Illinois Department of Transportation "Manual of Instructions for the Structural Design of Bituminous Pavements" except in those instances where the minimum requirements of subsections (D)7 and (D)8 above override.
The developer shall submit design traffic and structural design data to the Village for review. Commercial and industrial traffic shall be based on generations common to the establishments to be served. Residential traffic shall be based on the following minimum traffic for lots five (5) acres or greater in size:
ADT per lot - 16 vehicle trips
Traffic Classification
Passenger car | 90% |
Single unit truck | 9% |
Multiple unit truck | 1% |
Traffic generation will be considered on an individual basis for residential developments of greater density than one lot per five (5) acres. Collector streets will be designed to accommodate traffic for the area served projected twenty (20) years into the future. Design traffic will be determined through a coordinated effort by the Village and the developer with all required traffic counts and field data being provided by the developer.
10. Accommodation of Construction Traffic: In those subdivisions where a majority of construction traffic due to home building will be confined to one road, additional structural strength will be provided in the road design as required by the Village Engineer.
11. Shoulders: Earthen shoulders will be constructed on each side and adjacent to the roadway surface. Shoulder widths to each side shall be four feet (4') on collector streets and two feet (2') on minor streets. All shoulders shall slope away from the surface edge at a rate of three-fourths inch (3/4") per foot.
12. Cul-De-Sacs: Minimum radius for outside edge of pavement shall be fifty feet (50'). Maximum length of cul-de-sac shall be two thousand feet (2,000').
13. Curb and Gutters: After consideration of existing topography, storm water drainage, and site conditions that may be disturbed by construction of the street, the Plan Commission may recommend curbs and gutters instead of ditches at selected locations or for the entire length of streets serving lots of one acre or greater in area. Concrete curb and gutters shall be required on all commercial and industrial streets and on all residential streets where lots are less than one acre in area. The design of the curb and gutter shall comply with the Village-approved standards on file with the Village Clerk.
(E) Private Street Design Standards: If private streets are approved by the Plan Commission, the streets shall comply with the public street design standards in Section 6-4-3(D) except as set forth below:
1. Streets serving two (2) through five (5) lots:
a. Surface Width: Minimum sixteen feet (16');
b. Surface Material: Minimum eight inch (8") thick aggregate surface coarse material composed of crushed stone or crushed gravel;
c. Easement Width: Minimum fifty feet (50') for streets and minimum fifty feet (50') cul-de-sac radii; and
d. Cul-De-Sac Radius: Minimum edge of pavement thirty-five feet (35').
2. Streets serving six (6) through ten (10) lots:
a. Surface Width: Twenty feet (20');
b. Surface Material: An A-3 bituminous surface treatment shall be applied to all streets;
c. Easement Width: Sixty-six feet (66') for streets and minimum sixty feet (60') for cul-de-sac radii; and
d. Cul-De-Sac Radius: Minimum edge of pavement forty feet (40').
3. Streets serving eleven (11) or more lots:
a. Surface Width: Twenty feet (20');
b. Surface Material: A bituminous concrete surface course of the following minimum thicknesses:
(1) On BAM Base Course - 2 inches.
(2) On Granular Basecourse - 21/2 inches.
c. Easement Width: Sixty-six feet (66') for streets and minimum seventy feet (70') for cul-de-sac radii; and
d. Cul-De-Sac Radius: Minimum edge of pavement fifty feet (50').
(F) Sidewalks and Pedestrian Ways: In residential areas, the Village, upon recommendation of the Plan Commission, may require sidewalks at selected locations on regional or area highways, collector and minor streets. Sidewalks and pedestrian ways in residential areas shall be five feet (5') in width at a distance of one foot (1') from the property line. Sidewalks for business areas shall be at least ten feet (10') wide and may abut the curb line. Concrete sidewalks shall be required on both sides of streets in commercial and industrial areas. Sidewalks for industrial areas shall be at least five feet (5') wide and may abut the curb line.
(G) Street Lighting: Upon recommendation of the Plan Commission, the Village may require that street lighting shall be installed in accordance with the Illuminating Engineering Society Standards.
(H) Landscaped Center Islands: Center islands generally shall not be used in cul-de-sacs in public streets. Upon recommendation of the Plan Commission, the Village may require that a landscaped center island be installed in any cul-de-sac on a private street serving eleven (11) or more lots and that appropriate maintenance provisions be incorporated into the subdivision's declaration of covenants and restrictions or other homeowners' association documents.
(I) Street Signs:
1. Street Name: Street name signs shall be erected at all intersections created by the development. All signs shall be mounted on a minimum two inch (2") I.D. galvanized steel post set in a poured concrete foundation extending a minimum of three and one-half feet (31/2') below finished grade. One post with double signs shall be required per intersection. Sign face material and design shall be in accordance with current Village standards.
2. Traffic Control: Traffic control signs shall be erected throughout the subdivision as required by the Village Engineer. All signs shall be mounted on enameled steel posts driven in the ground to a minimum depth of three and one-half feet (31/2') below finished grade.
Signs shall have a base of sheet aluminum with the sign face and legend being of reflectorized materials.
All work and materials relative to signs shall be in conformance with the current edition of the Illinois Department of Transportation "Manual on Uniform Traffic Control Devices for Streets and Highways" and the "Standard Specifications for Traffic Control Items".
(J) Special Soil Regulations for Streets:
1. Organic Soils: If the construction of proposed streets or roads in a subdivision is through organic soils, all organic materials shall be removed to solid subsoil in the area of the proposed street or road and replaced with fill materials that allow movement of ground water in its natural state through the fill and provide the required structural support for the roadway. All such streets shall be elevated above the expected high water in the area, as determined by the Soils Map, so as to provide a minimum of two feet (2') between the pavement surface and the water. In no instance shall the pavement base course be constructed within six inches (6") of the expected high water, as determined by the Soils Map.
2. Wet Soils: If the construction of proposed streets and roads in a subdivision are to go through wet soils, positive ground water control must be achieved. The surface of all roads shall be constructed at an elevation so as to provide a minimum of two feet (2') between the pavement surface and expected high ground water or free water surface. In no instance shall the pavement base course be constructed within six inches (6") of expected high water, as determined by the Soils Map. All designs shall insure that natural drainage is maintained. In no instance shall movement of ground water be impeded so as to promote build-up of hydrostatic pressure on one side or the other of a proposed roadway. (Ord. 93-5, 5-24-93)