9-Appendix A1 - Special Provisions.docx

ITEM NO. 9000-0001

SPEED CUSHION

I. DESCRIPTION – This work consists of constructing asphalt Speed Cushions in existing pavement at the locations shown on the plans, in accordance with these Special Provisions, the applicable provisions of PennDOT Publication 408, the latest edition of the MUTCD, and the approved Speed Cushion Detail.

II. MATERIAL –

· Asphalt - Provide superpave asphalt mixture design meeting the requirements of Publication 408, Surface Course, unless otherwise directed by the City Engineer.

· Tack Coat - Provide asphalt emulsion meeting the requirements of Publication 408, Section 460.

· Pavement Markings - Provide white pavement marking material meeting the requirements of Publication 408, Section 962.

· Signs - Provide signs and sign supports meeting the requirements of Publication 408, Sections 901 and 902, and the MUTCD.

III. CONSTRUCTION –

· General - Construct Speed Cushions in existing asphalt pavement at the locations and dimensions shown on the plans and standard details. Ensure all work conforms to the approved Speed Cushion Detail.

· Layout - Center the Speed Cushion within the travel lane as shown on the plans. Maintain a maximum spacing from the face of curb, ensure cushion spacing, overall width, and configuration conform to the standard detail. Do not place raised asphalt pavement surfaces in marked or unmarked crosswalks, over manholes, water or sewer valves or other irregularities in the roadway. Notify the City representative if the raised Speed Cushion cannot be placed. Obtain concurrence on the location from the City representative prior to installation.

· Saw Cutting and Milling - Saw cut the pavement to neat lines at the limits shown on the plans. Mill to the depth necessary to achieve a finished Speed Cushion height of approximately 3 inches ± ½ inch.

· Surface Preparation - Clean all saw-cut and milled surfaces of dust, debris, and loose material. Apply tack coat to all exposed vertical and horizontal surfaces prior to asphalt placement, in accordance with Section 460.

· Asphalt Placement - Place superpave asphalt in lifts sufficient to achieve the required profile and compaction.

Compact asphalt in accordance with the applicable requirements of Publication 408.

Ensure the finished Speed Cushion has a flat top section as shown on the detail, smooth transitions at tapers, and no cracking, segregation, or surface irregularities

· Pavement Markings - Install 12-inch-wide white pavement markings in advance of and across each Speed Cushion as shown on the plans. Install markings in accordance with Section 962 after the asphalt surface has cooled and cured.

· Signing - Install W17-1 (Speed Hump) warning signs in advance of each Speed Cushion location.

Install signs in accordance with the latest edition of the MUTCD and Publication 408.

IV. MEASUREMENT AND PAYMENT – Each.

Includes saw cutting, removal of the existing asphalt surface, milling, surface preparation, tack coat application, asphalt placement, compaction, pavement markings, signing, traffic control, and all labor, materials, equipment, and incidentals necessary to install a speed cushion as specified. Also incidental to this item is the removal of all existing speed cushions and associated signs within the project limits. Removed signs shall be salvaged and delivered to the City of Harrisburg at 1002 N. 7th Street, Harrisburg. No separate payment will be made for this work.

END OF SECTION ITEM NO. 9000-0001

Item No 9000-0001 – Speed Cushion