Louisiana Administrative Code › Title 70 - TRANSPORTATION AND DEVELOPMENT › Part I - Highway Construction › Chapter 3 - Roadside Vegetation Management › Section I-303 - Guidelines and Categories of Roadside Vegetative Maintenance

Current through Register Vol. 50, No. 6, June 20, 2024
A. 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.