La. Admin. Code tit. 70 § I-303
Current through Register Vol. 50, No. 11, November 20, 2024
Section I-303 - Guidelines and Categories of Roadside Vegetative MaintenanceA. General Conditions for All Highway Systems 1. DOTD will encourage the growth, planting and preservation of wildflower areas.2. The district roadside development coordinator shall monitor and coordinate planting of all wildflower areas. He will record locations of the plantings on DOTD Wildflower Inventory Form and return them to headquarters for placement in the master file.3. Wildflowers may be planted to within 30 feet of the roadway on multi-lane systems and 15 feet on two-lane facilities or the back of the required drainage channel, whichever is greater. Wildflowers that have naturalized and are 15 feet or more from the travel lane should be allowed to remain. Every effort should be made to mow around them and avoid spraying herbicides unless it is spot treatment to eliminate certain weed species. Wildflowers may be planted in medians providing that they do not interfere with sight distances. Naturalized species occurring in wet areas such as iris, lilies and cattails will be allowed to remain when they do not obstruct drainage. The district maintenance engineer will decide when plants are obstructing drainage or sight distances and will take the necessary action to correct the deficiency.4. Remove litter prior to mowing designated areas. For roads in the Adopt-A-Road Program, it would be beneficial to contact the sponsor agency and advise them of the mowing schedule in order for them to assist in the removal of litter prior to the mowing operation.5. Sight distance at horizontal curves, vertical curves, intersections, railroad crossings, signs, signal lights, delineators, hazard markers and warning devices should be clear of obstructions. Sight distance can be obtained on the inside of horizontal curves by mowing the area 30 feet from the edge of the surface or from the edge of the surface to the right-of-way line or from the edge of the surface to the fence line, whichever is the shortest distance. Transition should begin 150 feet prior to the beginning and end of the curve. All vegetation shall be maintained to permit clear visibility for all regulatory traffic signs. Trim or remove trees that interfere with proper sight distance or side and overhead clearance.6. All vegetation shall be maintained to permit clear visibility for all regulatory traffic signs. Trim or remove trees that interfere with proper sight distance, or side and overhead clearance.7. All dead trees or leaning trees with weakened root systems within DOTD rights-of-way which may endanger traffic by falling across the highway shall be removed and disposed of in a timely manner. Stumps within a mowable area are to be removed to ground level with a stump removing machine. If the stumps are located in an area designated not to be mowed, they may remain but should be cut to within 5 inches of ground level.8. In order to ensure proper drainage, mow to the top of backslopes. When ditch bottoms are inaccessible and impeding drainage, treat unwanted vegetation with an approved herbicide labeled for use over water.9. Mowing heights should be 5-6 inches; shorter cutting heights may cause stress on the vegetation and damage to equipment. Do not mow during long rainy spells and when the right-of-way is too wet. Mowing during these times will cause rutting and possibly cause erosion in the future.10. Observe and initiate appropriate erosion control procedures when necessary.11. General herbicide treatment is to be confined to an area of approximately 30 foot widths from the edge of all roadways where right-of-way is available or to the back of the required drainage channel to ensure proper drainage. Spot treatment is allowable beyond this area.12. Treat pavement edges, paved medians, riprap areas and areas around delineators, guardrails and signs with appropriate herbicide. Treat designated areas of roadsides with appropriate herbicide two weeks prior to mowing cycle to eliminate noxious grasses and weeds. Some areas may need hand trimming because of herbicide restrictions. Prior to treating rights-of-way on federally owned lands, obtain the proper authorization from the federal agency having jurisdiction and make herbicide applications in accordance with their guidelines. Do not spray herbicides in designated or native stands of wildflowers unless absolutely necessary to control weed infestation. When treating unwanted vegetation in wildflower areas, every effort should be made to spot treat the unwanted vegetation.13. When practical, every attempt should be made to blend the highway right-of-way with the adjacent land uses. For example, forest lands should extend into the right-of-way, subject to clear zone requirements, and rights-of-way adjacent to crop and pasture lands should remain relatively open.B. Urban (Highway Systems). Urban shall mean within the recognized limits of small towns, villages and municipalities as well as incorporated areas of cities. 1. Maintain all rights-of way by using a minimum cutting height of 5 inches. A maximum height of 8 inches will be allowed prior to mowing.2. Remove all dead ornamental plants and replace during the proper planting season with appropriate type of plant.3. Wildflowers may be planted in large interchange areas and shall not be mowed until the mature seed has set. Utilize the 5-inch minimum mowing height up to the limits of the wildflower planting area. Wildflowers which will attain a height of 24 inches or more will not be permitted in narrow medians, or in sight triangles where they will interfere with adequate sight distances. General Conditions, §303. A.3 outlines other facts concerning wildflower plantings.4. Transition mowing standards between urban and rural categories with a long, smooth, flowing line. This transition should occur over a distance of approximately 2,000 feet.C. Rural1. Interstatea. Begin mowing operations, except wildflower areas once vegetation has reached approximately 12 inches in height. Maintain right-of-way using a 5-inch cutting height.b. Mow all mowable areas, except wildflower areas a minimum of three times each year. Medians are to be mowed in their entirety each mowing cycle except where wildflowers, shrubs or trees are present. Weather permitting, these mowings should occur in May, August and in late October or November.c. Wildflowers will be permitted as in §303. A.3 under urban systems. Maintain the 18-inch maximum vegetation height up to the limits of the wildflower planting area. Wildflower areas are allowed to naturally reseed within 15 feet of travel lane.d. Mow wildflower areas after they have gone to seed. For spring blooming varieties this should normally occur in May and fall blooming plants should be mowed in late October or November. The roadside development district coordinator should be consulted to determine appropriate timing for mowing wildflower areas.e. Remove all dead ornamental plants as in §303 B, Urban Systems and replace during the proper planting season with appropriate type of plant.f. Herbicide applications are to be made in accordance with General Conditions, §303. A 11 and 12.g. Maintain frontage roads in the same manner as primary system.h. Weight enforcement scale areas are to be mowed in their entirety each mowing cycle using a 5-inch mowing height. Rest areas are to be mowed in accordance with EDSM No. IV.3.1.2.2. Primary Multi-Lane and Two Lane a. Begin mowing operations once vegetation has reached approximately 12 inches in 0 height, unless herbicides have established desirable vegetation and rendered mowing unnecessary. Mowing heights are to be 5 inches.b. Mow a 30-foot strip from the edge of the roadway surface to the top of the backslope to facilitate drainage, or to the right-of-way on multi-lane and two-lane roadways. Medians less than 80 feet in width are to be mowed in their entirety each mowing cycle. In medians which have been allowed to revegetate naturally, mow a 30-foot strip from the edge of the roadway surface or to the back edge of the ditch. Mowing should be accomplished a minimum of three times per year.c. Wildflowers will be permitted as in §303. A 3, Urban Systems.d. Mow entire mowable area of the right-of-way annually in late October and November after the wildflowers have bloomed and the seed has set. In areas which have been allowed to revegetate naturally, annually mow a 40-foot strip to eliminate woody growth.e. Mow interchange areas to same standards as roadways.f. Herbicide applications are to be made in accordance with General Conditions, §303. A 11 and 12.g. Maintain frontage roads in the same manner as primary system.3. Secondary and Farm-to-Market System a. Begin mowing operations once vegetation has reached a 12-inch height. Mowing heights are to be 4-6 inches.b. Mow a 15-foot strip from the edges of the roadway surface or to the back side of the ditch to facilitate drainage.c. Herbicide applications are to be made in accordance with General Conditions, §303. A or as determined by district personnel based on existing conditions.d. Annually mow entire mowable area in the fall, normally in late October or November after wildflowers have bloomed and the seed has set to prevent excessive woody growth.D. Intersections (All Systems) 1. Right-of-way permitting, mow to the sight distance transition limits specified herein.2. Mow all flare areas at junctions for sight distance.E. Mowing Exceptions 1. Areas where individuals or businesses mow right-of-way along their property.2. Areas where appropriate herbicide treatment can keep vegetation within the standards.3. Areas that are not applicable, i.e., wildflower areas.4. Areas where seedlings are planted and/or permitted to grow.5. Rest areas and tourist information centers, on the interstate system, are to be maintained by the caretakers in a lawn-type condition.6. Unmowable areas within defined mowing limits.La. Admin. Code tit. 70, § I-303
Promulgated by the Department of Transportation and Development, LR 17:204 (February 1991), amended by the Department of Transportation and Development, Office of Highways/Engineering, LR 26:1652 (August 2000).AUTHORITY NOTE: Promulgated in accordance with R.S. 47:820.6.