822.7 Definitions

Biological Control

Usually involves the use of insects and disease-causing agents that attack certain weed species. An example is the control of musk thistle with the thistle head weevil. For effective biological control, the insect or disease must affect only the weed requiring control and the insects must have few natural enemies that interfere with their activity.

Brush

Coarse woody vegetation growing in an undesirable location.

Chemical Control

The use of herbicides to control vegetation. Refer to EPG 821 Herbicides and Roadsides.

Ditch Line

Ditch lines are considered to be to the back of a flat bottom ditch and to the bottom of a "V" ditch for roadside vegetation management purposes.

Divided Highway

Highway with physical separation of traffic in the opposite direction.

Endangered Species

Plants or animals considered by the state or federal government to be in danger of extinction or require protection to maintain their existence.

Fully Developed Areas

Areas where the surrounding land is dominated by housing developments and commercial properties. There are no large gaps of areas without housing or commercial development.

Hardscape Features

Landscape materials such as timbers, segmental block retaining walls and boulders that could create an obstacle if they are in an unprotected path of the clear zone.

Herbicide Program

Utilize appropriate equipment, herbicides and trained personnel for the application of products as specified (EPG 821 Herbicides and Roadsides). The objective is to control noxious and undesirable plant species, as well as manage plant growth by applications of plant growth regulators and side trimming.

High Profile Areas

Areas with high traffic counts that may be subjected to idle viewing by the motorist and/or have considerable pedestrian traffic.

Integrated Roadside Vegetation Management (IRVM)

A decision-making and quality management process for maintaining roadside vegetation that integrates the following:

• needs of the local communities and highway users;
• knowledge of plant ecology, design, construction and maintenance considerations;
• monitoring and evaluation procedures;
• government statutes and regulations and
• technology

IRVM uses cultural, biological, mechanical and chemical pest control methods to economically manage roadsides for safety plus environmental and visual quality.

Invasive Plant Species

An aggressive plant species that tends to spread. This includes noxious weeds.

Islands

Areas surrounded by driving lanes, turn lanes or ramps, etc. They may be vegetated or paved. They may be at-grade or raised.

May

Permitted.

Median Width

Distance measured between the edge of traveled ways on a divided highway. The median width measurement includes the width of the inside shoulders.

Wildflower and Native Grass

Mowing Cycle

The amount of time to mow and trim an area or route from start to finish is one cycle.

Native Grasses

Grasses that occur naturally or were known to exist prior to European settlement.

Naturalized Areas

Areas that have been allowed to flourish with native or noninvasive plant growth. These areas may have a random mix of what has established on its own or have selected vegetation management practices used to promote optimum desirable growth.

Naturalized Areas

Noxious Weeds

A plant that is troublesome and undesirable, and declared so by state law. Noxious weeds are: Canada thistle, Scotch thistle, musk thistle, purple loosestrife, marijuana, Johnsongrass, multiflora rose, kudzu, cutleaf teasel, common teasel, and field bindweed. MoDOT is thereby required by law to control these plants on right-of-way. The Johnsongrass law is subject to county option. Regardless of county option, the department shall make an effort to control this plant on right-of-way. Methods of control are specific to individual plants (EPG 821 Herbicides and Roadsides) and shall be followed in developing control practices. Control efforts should be documented.

Noxious Weed Control

Documented efforts to reduce and possibly eradicate an undesirable or noxious weed. Efforts include both chemical and biological methods.

Plant Growth Regulators (PGR)

A chemical that suppresses the top growth of a plant.

Raised Medians

Areas between driving lanes that may be grass or paved (or a combination) and are elevated.

Right-of-Way Line

MoDOT's property line between MoDOT and adjacent property owner.

Shall

Mandatory.

Should

Strongly recommended.

Sight Distance

All vegetation should be maintained at intersections and curves along state rights-of-way to maximize drivers' visibility. Most sight distances can be maintained by a clear view unobstructed by vegetation, along the main roadway approximately 6 to 10 feet from the edge of the traveled way. At intersections created by cross roads and gore points, the sight distance may need to be extended if necessary.

Slope Indicators

A mechanical device that operates on the same basis as a (bubble) level by indicating the degree of slope.

Traveled Way

Portion of the roadway intended for movement of motorized traffic. The white line strip on the edge of the road surface would typically designate this.

Trimming

Vegetation control to eliminate unsightly growth remaining after the mowing is complete. Includes line trimming, pulling and other manual means. Vegetation control under or around fixed objects within the mowed area. To manage vegetation in such a manner that keeps it consistent with the surrounding vegetation.

Undesirables

Vegetation that chokes out, shades out or competes with the intended vegetation at the given location. This will include any plant in the wrong place. Undesirables would include but not limited to chicory, giant ragweed, phragmites, spotted knapweed and others. Noxious weeds are included in this category. Several are listed in EPG 821 Herbicides and Roadsides.

Undeveloped Areas

Areas that don't fall within the fully developed area definition.

Undivided Highway

Highway with no physical separation of traffic in the opposite direction.

Visible Litter

Trash in a size or quantity noticeable to roadway travelers.

V-Ditch

Ditch with little or no flat bottom.

Wildflowers

Reoccurring broadleaf flowering plant in a naturalized area.