California Department of Transportation
 

Highway Planting General Policy

Conventional Highways

Highway planting, funded and maintained by the Department on conventionalhighways, is limited to planting that provides: safety improvements (headlight glare screening, delineation of the roadway, fire suppression, and wind breaks), erosion control/storm water pollution prevention, highway planting revegetation, and required mitigation planting.

Freeways, Controlled Access Highways and Expressways

Highway planting is warranted on freeways, controlled access highways and expressways under any of the following conditions:

  • On new freeways, controlled access highways and expressways - areas impacted by new highway construction where adjacent properties are developed at the time of highway construction contract acceptance;
  • On existing freeways, controlled access highways and expressways - areas impacted by major modifications to the existing highway where adjacent properties are developed at the time of highway construction contract acceptance;
  • Where adjacent properties were developed on or before June 30, 1987;
  • To satisfy Memorandum of Understanding (MOU) or Memorandum of Agreement (MOA) between the Department and another governmental agency;
  • To mitigate for environmental impacts in compliance with environmental commitments, agreed to, for example, as a part of project development, resource agency permit requirement or court order;
  • To provide planting necessary for revegetation, erosion control, storm water pollution prevention or traffic safety improvements (headlight glare screening, delineation of roadway, fire suppression, and wind breaks).

Adjacent properties are considered "developed" when the streets or buildings are in place, or when the adjacent properties have approved construction permits. Parks and open space are not considered developed property unless they are an integral component of a planned development.

Highway planting along freeways, controlled access highways and expressways, that exceeds these provisions, will only be permitted when funded and maintained by others.

Separate Contract Requirement for Highway Planting Work on Roadway Construction Projects

Highway planting having an estimated cost of $200,000 or more, in conjunction with or resulting from a roadway construction project, must be accomplished by separate contract and must include three years of plant establishment. This policy applies to all highway planting projects within the State operational right-of-way regardless of the funding source. The estimated cost of highway planting is the total sum of the contract lump sum item for Highway Planting and the contract lump sum item for Irrigation Systems.

Highway planting having an estimated cost of less than $200,000, in conjunction with or resulting from a roadway construction project, may remain with the parent roadway construction project and must include one year of plant establishment. Exceptions to this policy must receive concurrence from both District Maintenance and the District Landscape Architect (LA), and be approved by the Landscape Architecture Program (LAP).

The cost limit which triggers the separate contract requirement for highway planting work may be adjusted for inflation by the LAP.

Exceptions to the separate contract requirement policy may be granted by the Principal, LAP, when there is a demonstrated benefit to the State to combine planting with road construction under a single contract, or the planting work is legally required to be installed with the roadway construction contract. Submit exception requests to the LAP using the form entitled "Fact Sheet Exception to Separate Contract Policy for Highway Planting" in Appendix D of this Manual. Exception requests must be approved by the LAP prior to approval of the Project Report.

Funding Limitations

The maximum cost per acre for highway planting work, and the maximum cost per acre for water assessment fees for highway planting projects have been established, and are adjusted annually, by the LAP. These values establish the Department funding limit for highway planting and water assessment fees. Required mitigation planting, traveler and worker safety, and roadside management items are not included in the maximum cost per acre limit for highway planting.

Exceptions to this policy must be approved by the Principal, LAP, and may be considered where the highway planting work is funded and maintained by others; where a higher level of highway planting is required due to legal agreements; to replace planting originally provided by others; or for planting of narrow roadside areas such as vine planting on noise barriers.

Planting with Noise Barriers

Planting should be incorporated as an integral component of noise barrier work to discourage graffiti and address visual impact issues. Wherever graffiti removal or other visual issues represent an ongoing maintenance concern, consideration must be given to covering new or existing noise barriers with vines and/or placing plants to screen the noise barriers to reduce worker exposure and life-cycle maintenance costs related to graffiti removal.

Planting associated with noise barrier construction must be programmed and funded as part of the parent project. The cost of the work should be identified in the initiation document for the parent project. This planting must be programmed to be under construction within two years after highway construction contract acceptance. For specific information regarding project programming, please refer to Chapter 9 "Project Initiation" of this manual.

Plant Establishment

A plant establishment period is a duration of time that allows newly installed plant material to reach a state of maturity, requiring minimal ongoing maintenance for survival. A plant establishment period typically includes the removal of litter and trash, weeding, water application, irrigation repair, replacement of plant material that dies, and other activities required to ensure the long-term survival of plant material.

FHWA regulations require a plant establishment period of sufficient length for the expected survival of new plant material in the highway environment on all projects that include highway planting.

Plant establishment periods for highway planting performed in conjunction with a roadway construction project must follow the policy described in "Article 1 – General Policy, Highway Planting, Separate Contract Requirement for Highway Planting Projects".

Plant establishment periods for highway planting performed under a separate contract from a roadway construction project must be three years in length. Plant establishment periods for required mitigation planting may exceed three years when required by the permit. Exceptions to this policy must receive concurrence from both District Maintenance and the District LA and approved by the Landscape Architecture Program (LAP).

Replacement Highway Planting

Replacement highway planting replaces vegetation installed by the Department or others, that has been damaged or removed due to transportation project construction. Replacement highway planting may also include irrigation modifications and/or replacement. The Department will replace vegetation (including planting by others) damaged or removed by State transportation construction activity. Vegetation will be replaced at a rate and size determined by the District LA.

If a highway construction project, funded by others, is proposed for an area in which the operational right of way is currently planted, the project proponent must provide replacement planting equal to the current allowable maximum cost per acre. If they desire, the project proponent may provide replacement planting which exceeds the current allowable maximum cost per acre. See "Maintenance Responsibilities - Planting by Others" of this document regarding maintenance responsibilities for planting which exceeds the maximum cost per acre.

If there is limited space for replacement planting due to transportation construction, replacement planting may be installed outside the limits of the parent highway project. Replacement planting may be located outside the State operational right-ofway if it is in a public space within the adjacent community. The District LA and the appropriate public agency should negotiate and agree on the location of this planting and the terms of the maintenance agreement.

Replacement highway planting required due to the impacts of a roadway construction project must be programmed in conjunction with and funded from the parent project. The cost of highway planting work should be identified in the project initiation document for the parent project. The Project Approval and Environmental Document phase of work for the parent project should include the planting project within its project scope. Replacement highway planting must be under construction within two years of acceptance of the highway contract that damaged or removed the existing planting. For specific information regarding project programming, please refer to Chapter 9 "Project Initiation" of this manual.

Required Mitigation Planting

Required mitigation planting provides planting and other work necessary to mitigate environmental impacts due to roadway construction. The word "required" indicates that the work is necessary to meet legally required environmental mitigation or permit requirements.

Examples of work involved in mitigation planting may include:

  • Creation, restoration or enhancement of habitat such as wetlands, oak woodlands, etc.
  • Creation, restoration or enhancement of specific habitat for sensitive species such as elderberry plantings for the Valley Elderberry Longhorn Beetle or nesting habitat for Least Bell's Vireo.

Required mitigation planting may be performed within the operational right-of-way, immediately adjacent to the highway or at an offsite location as determined by the permit.

A planting project for required mitigation due to the impacts of a roadway construction project must be programmed and funded as part of the parent project. The cost of required mitigation planting should be identified in the project initiation
document for the parent project. This planting must be under construction within two years of acceptance of the highway contract that damaged or removed the existing planting, unless otherwise specified. For specific information regarding project programming, please refer to Chapter 9 "Project Initiation" of this manual.

Highway Planting Revegetation

Highway planting revegetation provides planting as mitigation for native vegetation damaged or removed due to a roadway construction project. Highway planting revegetation may include irrigation systems as appropriate.

Highway planting revegetation, required due to the impacts of a roadway construction project, must be programmed and funded as part of the parent project. The cost of the work should be identified in the project initiation document for the parent project. This planting must be programmed to be under construction within two years after acceptance of the highway contract. For specific information regarding project programming, please refer to Chapter 9 "Project Initiation" of this manual.

Scenic Resource Evaluation

The environmental review process requires an analysis of a project's potential impact on scenic resources. Scenic resources such as large trees, rock outcroppings, scenic vistas, or structures with visual interest must be identified in a preliminary scenic resource review prepared during the Project Initiation Document (PID) phase of work. If this preliminary review identifies a significant impact on scenic resources, a Scenic Resource Evaluation (SRE) is prepared during the Project Approval and Environmental Document (PA&ED) phase of work. A proposed transportation
mprovement that damages or requires removal of a scenic resource, cannot be classified Categorically Exempt under CEQA. Specific information regarding determination of scenic resources is described in the Department's Standard
Environmental Reference.

Visual Impact Assessment

An assessment to analyze visual impacts must be carried out when an initial review concludes that a proposed project may have an effect on a scenic resource or the visual environment. The visual assessment can document potential impacts and their significance. The assessment also provides recommendations for appropriate impact avoidance or mitigation strategies. District LAs are responsible for conducting the visual assessment, and should be contacted early in the project development process.

Wildflower Planting

California native wildflowers must be included with all projects with Federal participation that include planting work per Title 23 Code of Federal Regulations part 752.11. Highway planting to provide traffic safety improvements (see "Conventional Highways" above), revegetation, erosion control, and irrigation-only projects are exempt from this requirement.

The minimum level of native wildflowers required is one-quarter of one percent of the total funds expended for planting and irrigation work.

Project Reports must include a discussion of the proposed use of wildflowers and compliance with federal wildflower requirements. See Appendix D of this manual, "Preparation Guidelines for Project Report (New Highway Planting and Highway Planting Restoration), Section 6. Considerations Requiring Discussion, E. Use of Wildflowers."

The use of native wildflowers may not be appropriate under conditions such as the following:

  • Where native, non-endemic wildflowers are considered invasive to natural areas, or competitive with endemic native species.
  • Where native wildflowers would produce excessive dormant season fire fuel that increases the threat of wildfires and/or fire safety management will damage the wildflower resource itself.
  • Where wildflowers would not be compatible with the adjacent urban landscape environs.
  • Where the use of native wildflowers would result in poor planting design.
  • In areas where human impacts, such as trampling, would preclude successful establishment of native wildflowers.
  • Where irrigation necessary to sustain adjacent planting would lead to the decline of native wildflowers
  • Other unique project related situations or conditions.

The Project Report must describe the specific reason why the use of native wildflowers is not appropriate with the project. In these situations, an estimate of the dollar value of the required wildflower element for the project must be included in the Project Report. These funds are to be tracked by the District for use in developing future native landscape restoration projects for compliance with the federal wildflower obligation.