A. Subgrade, Sub-Base, Base Course and Wearing Surface Requirements.
The following are considered to be minimum street construction standards; more restrictive standards may be applied if conditions warrant:
Street | Prepared Subgrade | Subbase | Base Course | Wearing Surface |
Arterial St. | Yes | 4" | 10" Crushed Aggregate | Bit. Surface Course ID-2A, 2 1/2" (1" Wearing Course in 1 1/2" Binder) |
Collector St. | Yes | None | 10" Crushed Aggregate | Same as above |
Local St. | Yes | None | 8" Crushed Aggregate | Same as above |
Commercial Driveways & Parking Areas | No | None | 8" Crushed Aggregate | Same as above |
Bituminous Sidewalks | No | None | 4" Stone | 4" Bituminous Material |
Concrete Sidewalks | No | None | 4" Stone | 4" Cement Concrete 3,000 P.S.I. |
B. Construction Requirements:
1. Subgrade:
Wherever practical, the subgrade shall be in cut, or undisturbed subsoil, or on properly prepared embankment, and in no case shall the subgrade be made of filled or undisturbed topsoil or any other unsuitable material. Compaction shall be accomplished by sheepsfoot, smooth-wheel, or rubber-tired roller in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended and/or directed by the Township Engineer. Subgrade shall be compacted, tight and dry, and shall be soft and spongy under the roller. Compaction of the subgrade shall extend the full width of the cartway.
2. Base Course:
The base course shall be constructed on an 8 inch layer of No. 3 Aggregate, Type B, stone or better after compaction, on a 1 inch cushion of fine material composed of No. 1 Aggregate, Type B, or better. No slag will be permitted. Both fine and course material used for base courses shall be placed and compacted in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended and/or as directed by the Township Engineer.
2A. Base Course - Alternate:
As an alternate to Section 2 above, or when required by the Township, the Developer shall use bituminous concrete paving as a base course. This shall consist of a 3 inch layer of sub-base constructed of 2A, Type C, stone, compacted to not less than 100% percent of its dry weight density in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended. Bituminous concrete base course shall be placed over the prepared sub-base in a 5 inch layer after compaction. Bituminous concrete base course shall be mixed, delivered, placed, and protected in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended and all supplements thereto.
3. Prime Coat:
Regardless of the type of base course used, a bituminous prime coat shall be applied prior to placing the surface courses. Application of the prime coat shall be in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended. No traffic will be permitted to travel over the base course during the curing period.
4. Pavement:
Surfacing shall consist of ID-2A or ID-2 butuminous concrete placed in two courses. A binder course, having a compacted depth of 1 1/2 inches, and surface course, having a compacted depth of 1 inch. All material shall be placed with a mechanical paving machine in accordance with Pennsylvania Department of Transportation Specifications Form 408 as amended. All wearing courses shall be sealed to the concrete curb with 1 foot wide grade BM - 1 or A-1 bituminous gutter seal.
5. General:
a. Crown board and straight edge shall be used for checking street construction. Maximum tolerance shall not exceed 1/4 inch in the finished surface.
b. Delivery slips for all material deliveries shall be furnished in duplicate, with a copy provided for the township records.
c. Failure to adhere to the above specifications shall give the Township Council cause to refuse to accept streets for dedication.
d. In case of proposed major subdivisions, having lots abutting any existing street, paving and other street improvements shall be required for such existing streets to an extent as may be deemed by the Township Council to be in the public interest.
C. Super-Elevation and Cross Slope.
1. Crown:
A normal crown shall be provided on all streets not super-elevated, of 5/16 inch per foot straight slope extending in cross-section from edge of pavement to centerline or from edge of pavement to medial edge, whichever will apply, symmetrical to the centerline.
2. Design Procedures:
All super-elevated roadway sections shall be designed in accordance with the procedures outlined in the Pennsylvania Department of Transportation Design Manual, Part 2, Highway Design.
D. Curbing.
1. Curb shall be standard 7 inches by 8 inches by 18 inches cement concrete curbing with an 8 inch reveal as indicated on Plate RC-64 in PennDOT Publication #72, "Standards for Roadway Construction".