Milling shall progress in the direction against normal traffic in the lane being milled unless otherwise specified by the Engineer. All construction traffic entering or leaving the work area shall move in the direction of traffic of the open lane. Milling shall begin and end at lines normal to the pavement center line within any one milled area and at the project limits. This will not be required at the end of each shift. The depth of adjacent cuts shall be controlled to result in a smooth, uniform cross section, free from irregularities between adjacent passes of the milling equipment. There shall be no transverse troughs due to lowering the drum below the cutting plane (caused by continued down pressure when forward motion of the machine has stopped). Each traffic lane shall be milled with not more than two passes, but additional passes in the cutting path may be necessary to secure a smooth profile. A single pass shall not extend to both sides of the center line or a lane line between traffic lanes; however, the first pass at the center line or lane line shall overlap the joint line approximately 2 inches (50 mm), to minimize spalling. The joint match, if any, between two passes in a traffic lane shall be within 1 foot (0.3 m) of the center of the lane, to avoid joints directly in the wheel path, and shall be reasonably straight or parallel to the center line or lane line. Each pass shall be designed to maintain the existing crown and a taper from center line to pavement edge.

The transverse slope of the milled pavement shall be uniform to a degree that there is no depression or misalignment greater than 1/4 inch in 12 feet (6 mm in 3.6 m) when tested by stringline or straightedge placed perpendicular to the center line. The joint match between two adjacent passes shall match within 1/8 inch (3 mm).

In order to match the outside edge of the pavement, adjacent paved areas (for example, shoulders, curb and gutter, turn lanes, tapers, paved crossovers, and so forth) shall be milled to minimize vertical projections.

The finished surface shall have a uniform, coarse texture, subject to approval of the Engineer. The forward speed of the milling machine shall be controlled to prevent the formation of visible corrugations on the pavement surface.

2531.04 SMOOTHNESS.
The pavement shall be partly profiled on the initial trace by the Engineer using the procedure described in Article 2316.02. The average profile index for each area may be shown in the contract documents. The bidder is also advised that all profilograph information is available for inspection at the Office of Contracts, by a request to the Contracts Engineer. After the contract is awarded, the profilograph information will be available from the Engineer. This information represents a summary of conditions found to exist at the time the survey was made. The availability of this information will not constitute a guarantee that a profile other than that indicated will not be encountered at the time of milling.

The Contractor shall provide a control profilograph trace as described in Article 2316.02 prior to performing any grinding work. This control trace will be used to identify the required smoothness for the project. Each segment of the finished ground surface shall have a final profile index of 35% of the control profilograph trace or 10 inches per mile (160 mm/km), whichever is greater, and shall not include any bumps exceeding 0.5 inches in 25 feet (13 mm in 8 m). Depressed pavement areas due to subsidence or other localized causes, and areas where the maximum cut at mid panel or a fault restricts further milling will be excluded from testing with the profilograph when approved by the Engineer.

Profilograph testing shall end 15 feet (5 m) prior to excluded areas and shall resume 15 feet (5 m) following excluded areas.

The milled surface shall be tested and evaluated in accordance with Section 2316, with the following modifications:

1. The test is to be run and the profilograph is to be evaluated using the same procedure as for the control trace.

2. Each segment for which continuous milling is designated will be evaluated individually, and it shall meet the smoothness and bump requirements specified above, regardless of its length.

3. In excluded areas, smoothness requirements will be modified or may be waived by the Engineer.

4. The Contractor shall certify smoothness of the finished surface in accordance with Article 2316.03.

5. The Engineer may test for smoothness and bumps near the center line and at other spot locations where compliance is questioned. Additional milling may be required.

6. The original and final profilograph trace shall not be used to determine milling depth.

2531.05 LIMITATIONS.
Lane closures necessary to accomplish this work shall be as shown in the contract documents, or as directed by the Engineer. The entire roadbed shall be opened to traffic at the end of the working period. Uncompleted sections may be opened to traffic without completion of milling across an entire lane.

Overnight lane closures will not be permitted. Work will not be permitted on Sundays or holidays described in Article 1108.03. Article 1107.08 and Article 1107.09 shall apply.

Removal of all slurry or residue resulting from the milling operations shall be continuous, and shall not be deposited on the slab or paved shoulder. Pavement and paved shoulders must be left in a clean condition. Residue from milling operations should not be permitted to flow across lanes occupied by public traffic or to flow into gutters or other drainage facilities. This residue may be placed on the shoulder or foreslope, or removed in accordance with Article 1104.08.

When the following work is included in the contract, the operations shall be sequenced in the following order:

a. undersealing
b. longitudinal subdrains
c. patching
d. milling
e. installation of load transfer
f. crack and joint sealing

2531.06 PAVEMENT MARKINGS.
The pavement shall be marked in accordance with Section 2527; however, pavement marking of edge lines on Interstate pavement may be delayed up to 24 hours, after the lane is opened to traffic. Pavement marking will not be allowed on Sundays or holidays, unless otherwise approved by the Engineer.

2531.07 METHOD OF MEASUREMENT.
The Engineer will calculate in square yards (square meters) of pavement milled, for each type of coarse aggregate from the length of each area and the nominal pavement width.

Adjacent paved areas milled to minimize vertical projections will not be measured for payment.

2531.08 BASIS OF PAYMENT.
For the number of square yards (square meters) of Pavement Surface Repair, (Milling Limestone) or (Milling Gravel), completed and measured as provided above, the Contractor will be paid the contract unit price per square yard (square meter). This payment shall be full compensation for furnishing all equipment, materials, and labor to mill the pavement and test for smoothness according to the contract documents, including removal of slurry and residue from the project.