Aggregate—Crushed aggregate or mined gravel is used to provide a reasonably smooth and maintainable roadway travel surface, reduce erosion, and improve surface drainage of roads. The surfacing material must be replaced at intervals because of mixing with the subsoils, degradation of the rock, and loss of surfacing material as traffic and maintenance gradually moves it off the roadway. Aggregate is quarried at commercial or forest-owned sources. It may be crushed within or outside the forest with portable or stationary equipment and hauled to the roadway. Portable rock crushing equipment is used in many locations, both within and outside the forest boundaries. Aggregate may be stockpiled in centralized locations.

Road grading—A road grader with a 12- to 14-foot-wide blade removes surface irregularities, restores surface drainage features, and smooths the roadway surface to improve safety and user comfort. Grading is typically completed by making three to four passes over the entire road surface from beginning to end. Aggregate and native surface material is moved back and forth across the road surface during this operation.

Ditch cleaning—Roadside ditches are installed to intercept overland or underground water flow, drain road surfaces, and guide water away from the roadway and shoulders. Ditches become overgrown with vegetation over time, which hinders ditch performance. Ditches are periodically maintained by removing vegetation using a grader or rubber-tired backhoe.

Drainage Structures—Enclosed culverts, open-top culverts, underdrains, and diversion structures guide water over, beside, or under roadways and protect the roadway from erosion. They also protect waterways from traffic-associated degradation and may allow for aquatic organisms to pass from one side of the roadway to the other. They must be cleaned regularly and eventually must be replaced. Heavy equipment is usually required for this job, disturbing large areas of soil.

Brushing—Woody vegetation is pruned from road cut and fill slopes to improve the sight distance and stop the encroachment of brush and trees into the road prism. Brushing is normally done every 3 to 10 years, depending on how quickly the brush grows back. Brushing is usually accomplished using a machine with heavy-duty rotary or flail-type blades on an adjustable boom.

Mowing—Roadsides are mowed where needed for esthetic or safety reasons or to keep flammable grasses and forbs away from the road shoulder. A sickle- or rotary-type mowing machine is used. The frequency of mowing varies, depending on how quickly the vegetation grows, the length of the growing season, and the flammability of the vegetation. Commonly, mowing is done once a year during the latter half of the field season.

Fences, gates, cattle guards, guardrails, signing, and delineators—These auxiliary structures improve safety and separate vehicles from other traffic and animals. Like all structures, they must be maintained, and they must be replaced when they are damaged or worn out. Soil is disturbed when these structures are anchored in place.

2081—MANAGEMENT OF NOXIOUS WEEDS.

2081.2—Prevention and Control Measures.

Roads.

A. Required Objectives and Associated Practices.

1. Incorporate weed prevention into road layout, design, and alternative evaluation. Environmental analysis for road construction and reconstruction will include weed risk assessment.
   
   
2. Remove the seed source that could be picked up by passing vehicles and limit seed transport.

   (a) Remove all mud, dirt, and plant parts from all off-road equipment before moving into project area. Cleaning must occur off National Forest lands. This does not apply to service vehicles that will stay on the roadway, traveling frequently in and out of the project area.
   
   (b) Clean all equipment prior to leaving the project site, if operating in areas infested with new invaders as determined by the forest weed specialist. Reference Contract Provision C/CT 6.626.

3. Reestablish vegetation on bare ground due to construction and reconstruction activity to minimize weed spread

   (a) Revegetate all disturbed soil, except the travel way on surfaced roads, in a manner that optimizes plant establishment for that specific site, unless ongoing disturbance at the site will prevent weed establishment. Use native material where appropriate and available. Use a seed mix that includes fast, early-season species to provide quick, dense revegetation. To avoid weed contaminated seed, each lot must be tested by a certified seed laboratory against all State noxious weed lists and documentation of the seed inspection test provided.
   
   (b) Use local seeding guidelines for detailed procedures and appropriate mixes. Use native material where appropriate and available. Revegetation may include planting, seeding, fertilization, and weed-free mulching as indicated by local prescriptions.
   
   (c) Monitor and evaluate success of revegetation in relation to project plan. Repeat as indicated by local prescriptions.

4. Minimize the movement of existing and new weed species caused by moving infested gravel and fill material. The borrow pit will not be used if new invaders, defined by the forest weed specialist, are found on site.
   
   
5. Minimize sources of weed seed in areas not yet revegetated. If straw is used for road stabilization and erosion control, it must be certified weed-free or weed-seed free.
   
   
6. Minimize roadside sources of weed seed that could be transported to other areas.

(a) Look for priority weed species during road maintenance and report back to district weed specialist.

(b) Do not blade roads or pull ditches where new invaders are found.

(c) Maintain desirable roadside vegetation. If desirable vegetation is removed during blading or other ground-disturbing activities, area must be revegetated according to section (3) (a), (b), (c) above.

(d) Remove all mud, dirt, and plant parts from all off-road equipment before moving into project area. Cleaning must occur off National Forest lands. (This does not apply to service vehicles that will stay on the roadway, traveling frequently in and out of the project area.)

(e) Clean all equipment prior to leaving the project site, if operating in areas infested with new invaders, as determined by the forest weed specialist. Reference Contract Provision C/CT 6.626.

(f) Straw used for road stabilization and erosion control
will be certified weed-free or weed-seed-free.

7. Reduce weed establishment in road obliteration/reclamation projects. Revegetate according to section (3) (a), (b), (c) above.

B. Recommended Objectives and Associated Practices.

1. Retain shade to suppress weeds. Consider minimizing the removal of trees and other roadside vegetation during construction, reconstruction, and maintenance, particularly on southerly aspects.
   
   
2. Consider reestablishing vegetation on bare ground due to construction and reconstruction activity to minimize weed spread. Road maintenance programs should include scheduled fertilization to maintain vigor of competitive vegetation (3-year period suggested).
   
   
3. Minimize the movement of existing and new weed species caused by moving infested gravel and fill material. All gravel and borrow sources should be inspected and approved before use and transport. The source will not be used if the weeds present at the pit are not found at the site of intended use. If weeds are present, they must be treated before transport and use.
   
   
4. Minimize roadside sources of weed seed that could be transported to other areas. Weed infestations should be inventoried and scheduled for treatment.
   
   
5. Ensure that weed prevention and related resource protection are considered in travel management. Consider weed risk and spread factors in travel plan (road closure) decisions.
   
   
6. Reduce weed establishment in road obliteration/reclamation projects. Consider treating weeds in road obliteration and reclamation projects before roads are made undriveable. Monitor and retreat as indicated by local analysis and prescription.
   
   
7. Evaluate and prioritize noxious weeds along existing Forest Service access roads leading to project area and treat as indicated by local analysis and prescriptions, before construction equipment moves into project area. New road construction must be revegetated as described in Weed Prevention measure (see section (3) (a), (b), (c) above).

Itchgrass was introduced to Florida from the Philippines in the 1920s as a
pasture grass. The tall, aggressive grass has infested roadsides
throughout the southeastern United States, displacing native plants
.—Photo by the USDA Animal and Plant Health Inspection Service, Oxford, NC, archives.
Image 1149131 courtesy of Forestry Images.