Section 2612. Mowing


2612.01 Description.

Mow a strip of vegetation along the edges of shoulders, in the medians, and within designated interchange areas. Perform incidental hand mowing around obstacles.


2612.02 Materials.



2612.03 Mowing.


A. Equipment.


1. Use tractors with sickle type mowers, underbody rotary mowers, gang type rotary mowers, or other types the Engineer approves. Equip rotary mowers with a suction type blade and safety chains or other approved protective devices. Ensure sickle bar mowers have protective shields on all sections. Replace broken sections to ensure a clean, smooth cut. Make available on the project an extra set of operable blades to fit available equipment.


2. Equip each tractor with an amber revolving light:

         Visible from the front and rear,

         Mounted at least 10 feet (3 m) high as measured to the lamp axis, and

         Flashes between 60 and 120 times per minute.


3. In lieu of an amber revolving light, an amber strobe light may be used.


4. Equip each tractor with a standard triangular slow moving vehicle emblem mounted 4 feet (1.2 m) above the ground with a dimension of 13 1/2 inches (345 mm) per side, a red or fluorescent orange flag, and a rear view mirror. Locate as shown in the contract documents. Use a flag that is 16 inches by 16 inches (400 mm by 400 mm) minimum.


5. Set mower cutting height so that, after completion of the mowing operation, the height of remaining stubble averages 6 inches 1 inch (150 mm 25 mm).


B. Types.


1. General.

a. The contract documents will specify the type of mowing required. The Engineer will issue a Notice to Proceed to the Contractor for each mowing, based on the projected date when 50% of the vegetation will reach 14 inches (350 mm).

b. Mow a strip of vegetation 15 feet (4.5 m) wide immediately adjacent to the edges of the shoulders and throughout the length of the project. This also includes outside and inside ramp shoulders.


2. Metro Mowing.

a. Metro mowing consists of three to four mowings as stated in the contract documents. Approximate start dates are usually prior to Memorial Day, late June to early July, early to mid August (in a four mowing contract), and after Labor Day.

b. Mow the entire median. In addition to mowing along the shoulder and in the median, mow all other accessible areas including foreslopes, backslopes, ditch bottoms, interchange areas, islands, and along fences.


3. Spring and Fall Mowing.

a. Spring and fall mowing consists of two to four mowings, as stated in the contract documents. Approximate start dates are usually prior to Memorial Day, late June to early July, early to mid August (in a four mowing contract), and after Labor Day.

b. Mow the entire median.


4. Fall Mowing.

a. Fall mowing consists of one mowing, usually after Labor Day.

b. Mow the entire median.


C. Requirements.


1. Prior to mowing, examine the area to be mowed for objects that may cause damage. Immediately remove objects thrown onto the roadway.


2. Advance roadway warning signs will not be required.


3. When not mowing, limit mowing equipment travel to the right hand shoulder of the main line pavement. Do not travel in the traffic lanes except to cross the pavement for purposes of mowing adjacent to the left shoulder.


4. Do not use existing median crossovers. These are for emergency operations only. Confine turnarounds to interchanges.


5. Unless specified otherwise in the contract documents, perform all work during the hours of 30 minutes after sunrise to 30 minutes before sunset.


6. When mowing along the main line and right ramp shoulders, progress in the same direction as traffic. Mowing along the left ramp shoulder in the direction opposite the flow of traffic will be permitted if it can be accomplished without equipment using the left shoulder. Conduct mowing operations so that the equipment does not encroach on the traveled way. When mowing behind guardrail, the direction of travel may be opposite that of adjacent traffic.


7. To avoid leaving a ragged appearance, set the speed of the mowing equipment not to exceed the ability of the mower to cut cleanly. Monitor the operation and maintain the cutting edges in a sharp condition or replace as necessary to prevent unmown strips (rooster tails) or damage to vegetation.


8. Perform mowing in a single pass. If any unmown strip or damage to vegetation is encountered, immediately suspend the operation and take corrective measures, at no additional cost to the Contracting Authority. The Engineer may inspect cutting edges at any time. Additional mowing widths are permissible to take advantage of wider mowing equipment which may be difficult to modify to the required width. The Contractor will not be paid for this additional mowing width.


9. The contract documents will specify the limits of mowing at interchanges and rest areas, if applicable. When more than one pass of the mowing equipment is required, lap successive passes to avoid leaving uncut vegetation. More than one pass of the mowing unit may be necessary to accomplish the mowing. Bunching or windrowing of the mowed vegetation will not be permitted.


10. Hand equipment will be required for areas inaccessible to other equipment, and for trimming around and under delineator posts, sign posts, guardrail, bridges, culverts, or other obstructions. Complete the hand trimming within 3 working days after the adjacent area is mowed with the tractor. This may include hand pulling of weeds. At the direction of the Engineer, replace all roadside trees, shrubs, or appurtenances such as delineator posts, signs, tile systems, tile outlets, etc. damaged due to the mowing operations, at no additional cost to the Contracting Authority.


11. When wet soil conditions result in rutting, suspend mowing. At the direction of the Engineer, repair rutting damage caused by the mowing operation.


12. Parking of Contractor vehicles and equipment will be permitted within the Interstate right-of-way only at locations designated by the Engineer. In no case will they be allowed closer than 50 feet (15 m) from the shoulder. Parking of private vehicles within the Interstate right-of-way is prohibited.


2612.04 method of measurement.

The area for Roadside Mowing, in acres (hectares), will be shown in the contract documents. The quantity will be based on main line, center line, and ramp base line stationing, with the area calculated in. The length of shoulders at bridges will be deducted when calculating the quantity. The quantity at intersections of main line and ramp shoulders will be calculated so there will not be a deduction or a duplication of quantities. Additional mowing required around guardrails, obstacles, and median crossovers will not be measured separately.


2612.05 basis of payment.


A. Payment for Roadside Mowing will be the contract unit price per acre (hectare) indicated in the contract documents.


B. Payment is full compensation for mowing according to the contract documents, including:

         Mowing around guardrails, signs, delineators, drainage structures, bridges, and in islands, and

         Trimming with hand equipment.


C. When the Engineer determines mowing is not necessary due to factors such as the lack of vegetation growth during drought conditions, but hand trimming is still required, payment will be 25% of the contract unit price per acre (hectare).