(a) General standards.
(1) The location and width of all streets shall be in accordance with road and highway plans of the state and county. Streets shall be designed to provide adequate vehicular access to all lots or parcels with regard to topographic conditions, projected volumes of traffic and further subdivision possibilities in the area.
(2) The street system of a proposed subdivision or land development shall be designed to create a hierarchy of street functions.
(3) Local streets shall be designed so as to discourage through traffic and excessive speed.
(4) If lots resulting from the proposed subdivision are large enough to allow for resubdivision or, if a portion of the tract is not subdivided, adequate street rights-of-way to permit further subdivision shall be provided as necessary, and located so as to allow proper development of surrounding properties.
(5) Where a subdivision or land development abuts or contains an existing street right-of-way of improper width or alignment, the Planning Commission may require the dedication or reservation of additional land (ultimate right-of-way) sufficient to widen the street or correct the alignment. Where an additional dedication or reservation is required, all building setback lines will be measured from such dedicated or reserved right-of-way lines.
(6) All streets shall be graded and improved to conform to township construction standards and specifications.
(7) Road designs and specifications shall be approved by the Township Engineer, in accordance with the construction plans required for final plan review.
(b) Street right-of-way and cartway widths. Street right-of-way and cartway widths in proposed subdivisions and land developments shall conform to the minimum standards listed in Table 2 below:
Table 2 | ||
Street Design Standards | ||
Right-of-Way Width (ft.) | Cartway Width (ft.) | |
Arterials | As determined after consultation with the Township Engineer, the County Planning Commission and the State Department of Transportation | |
Collector | 60 | 36 |
Local, including culs-de-sac | 50 | 32 |
(c) Street grades.
(1) All streets shall have a minimum centerline grade of 1%.
(2) Centerline grades shall not exceed the following:
A. Local streets, 12%;
B. Collector streets, 18%; and
C. Arterial streets, 6%.
(d) Horizontal curves.
(1) Whenever street centerlines are deflected more than five degrees, connection shall be made by horizontal curves.
(2) To ensure adequate sight distance, minimum centerline radii for horizontal curves shall be as follows:
A. Local streets, 150 feet;
B. Collector streets, 300 feet; and
C. Arterial streets, 400 feet.
(3) A minimum tangent of 50 feet shall be required between reverse curves on local streets and between a curve and a street intersection where one of the intersecting streets is a local street.
(4) A minimum tangent of 100 feet shall be required between reverse curves on collector and arterial streets and between a curve and a street intersection where one of the intersecting streets is a collector or an arterial street.
(e) Vertical curves.
(1) When there is any change in grade, vertical curves shall be used.
(2) Vertical curves shall be designed to provide the following minimum sight distance:
A. Local streets, 200 feet;
B. Collector streets, 300 feet; and
C. Arterial streets, 400 feet.
(f) Intersections.
(1) Streets shall intersect at right angles whenever practicable, and no street shall intersect another at an angle less than 60 degrees.
(2) Multiple intersections involving the junction of more than two streets shall be avoided.
(3) Two streets intersecting a third street from opposite sides shall either intersect with a common centerline or their centerlines shall be offset as follows.
A. The two streets shall be separated by a distance of 150 feet between centerlines measured along the centerline of the street being intersected when all three streets involved are local streets.
B. The two streets shall be separated by a distance of 400 feet between centerlines, measured along the centerline of the street being intersected when one or more of the streets involved is a collector street.
C. The two streets shall be separated by a distance of 800 feet between centerlines, measured along the centerline of the street being intersected when one or more of the streets involved is an arterial street.
D. Clear sight triangles shall be provided at all intersections. The maximum height of any object within such triangles shall be two and one-half feet, and no object that could obscure the vision of a motorist shall be permitted. Such triangles shall be established as follows:
1. Seventy-five feet from the point of intersection of the centerlines of two intersecting local streets;
2. Two hundred feet from the point of intersection of the centerlines of two streets where one street is a collector street;
3. Four hundred feet from the point of intersection of the centerlines of two streets where one is an arterial street;
4. Whenever a portion of the line of such triangles falls within the proposed building setback line, such portion shall be shown on the final subdivision or land development plan and shall be considered a building setback line; and
5. Where the grade of any street at the approach to an intersection is greater than 4%, the street shall be leveled to no more than a 4% grade for a distance of at least 100 feet in each direction of the intersecting street.
(g) Cul-de-sac streets.
(1) Cul-de-sac streets permanently designed as such shall not furnish access to more than 30 dwelling units or potential dwelling units.
(2) All cul-de-sac streets shall be provided at the closed end with a fully paved turnaround. The minimum radius to the pavement edge or curb line shall be 40 feet, and a minimum radius to the right- of-way line shall be 50 feet.
(3) The centerline grade on a cul-de-sac turnaround shall not exceed 4%. The centerline grade on a cul-de-sac street shall not exceed 12%.
(4) Drainage of cul-de-sac streets shall preferably be toward the open end. If drainage is toward the closed end, water shall be conducted away in an underground storm sewer or by other means approved by the Township Engineer.
(h) Half streets and alleys.
(1) The creation of new half streets at the perimeter of a new subdivision or land development is prohibited.
(2) Alleys shall be prohibited in new subdivisions and land developments.
(i) Driveways.
(1) The minimum width of all residential driveways shall be 12 feet.
(2) All driveways shall be located no less than two feet from any lot line (except at the point of intersection with a street).
(3) The maximum grade of any residential driveway shall not exceed 10%.
(4) All driveways shall be surfaced with erosion resistant materials, approved by the Township Engineer, from the edge of the street cartway to a point in the lot not less than 25 feet from the right-of-way line.
(5) Whenever possible, the centerline of a driveway at the point of access to a street shall be located no closer to another street intersection than the following distances:
A. Fifty feet if intersecting a local street; and
B. Seventy feet if intersecting a collector street.
(6) Driveways intersecting arterials shall be discouraged.
(Ord. 668, passed 10-17-1990)