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Publication Number:  FHWA-HRT-17-008     Date:  December 2017
Publication Number: FHWA-HRT-17-008
Date: December 2017


Evaluation of Promoting Roadside Revegetation: An Integrated Approach to Establishing Native Plants

2. Evaluation Design

A logic model is a series of statements that links program components in a chain of causality. Program components include inputs, activities, outputs, outcomes, and impacts. Logic models describe the relationships among program resources, planned activities, and expected results; ultimately, they make explicit how program stakeholders expect program activities to affect change. The project team evaluating Roadside Revegetation traced the desired effects of the guide using the logic model in table 1.(1)

Table 1. Roadside Revegetation evaluation logic model.(1)




Short-Term Outcomes

Medium- and Long- Term Outcomes

  • FHWA R&T funding
  • Existing roadside revegetation research
  • FHWA/FLH staff
  • Partnerships with FLMAs
  • AASHTO partnership
  • Contractor support
  • Partnering with FLMAs to develop Roadside Revegetation technical guide(1)
  • Development of website(4)
  • Information gathering
  • Domestic scan of eight sites
  • Creation of case studies
  • Presentation at workshops and conferences
  • Roadside Revegetationguide
  • Managers’ guide(9)
  • Illustrative guide(10)
  • Interactive website
  • · Video(8)
  • Delivery of onsite training course(3)
  • Domestic scan report(7)
  • Poster(11)
  • Fact sheet(12)
  • Timeline graphic(13)
  • Awareness among
  • stakeholders of new roadside revegetation practices/ materials
  • Modified revegetation practice among stakeholders
  • Permanent adoption of more sustainable roadside revegetation practices
  • Improved safety
  • Avoided or reduced erosion
  • Reduced maintenance costs
  • Improved visitor experience
  • Enhanced environmental stewardship

AASHTO = American Association of State and Highway Transportation Officials.

The project team sought to answer the following two primary research questions regarding outcomes of the Roadside Revegetation and related material outputs:(1)

The first research question was intended to find whether Roadside Revegetation’s recommended practices had been effective in meeting end users’ needs.(1) In other words, did Roadside Revegetation materials encourage and help stakeholders change or supplement previous practices and with Roadside Revegetation techniques? The second research question was intended to examine the relationship between activities; outputs; and short-, medium-, and long-term outcomes. In other words, has the development and promotion of Roadside Revegetation, awareness of the materials, and adoption of the promoted techniques resulted in positive outcomes for the environment, safety, visitor experience, and maintenance costs (see table 2)?

Table 2. Performance measures for short-, medium-, and long-term outcomes.

Outcome Type

Evaluation Component

Performance Measures


Raised awareness among stakeholders of Roadside Revegetation(1)

  • Number of stakeholders aware by region, agency type, etc.
  • Number of information requests received by FHWA


Modified revegetation practice among stakeholders

Percentage of surveyed stakeholders who have adopted

Roadside Revegetation’s recommended practice


Improved safety

Survey and interview input on any available correlative data on accidents with and without use of recommended practices; otherwise, qualitative views on the topic


Avoided or reduced erosion

Survey and interview input showing degree of reduced erosion, if available; otherwise, qualitative views on the topic


Reduced maintenance costs

  • Survey and interview input describing cost comparison recommended versus alternate practices
  • Documented reduced herbicide or pesticide use


Improved visitor experience

Survey and interview input on whether visitors have noticed or commented on the qualities (e.g., beauty and driving experience) of a revegetated roadside with the recommended practices


Led to permanent adoption of more sustainable roadside revegetation practices

Survey and interview input on the benefits of using the recommended practices


Enhanced environmental stewardship

Survey and interview input on the benefits of using the recommended practices

2.1 Evaluation Methodology

The project team sought to answer the research questions by collecting both quantitative and qualitative information. The project team first conducted a review of relevant literature on roadside revegetation to begin the evaluation. Statistics from Roadside Revegetation’s website were then analyzed to gain insight on how interest in the guide may have changed over time.(4,1) The project team also solicited information from FHWA and USFS regarding past requests for copies of Roadside Revegetation or training on the guide’s principles. These background-gathering activities were followed by an online survey of revegetation practitioners and telephone interviews with select survey respondents to gain additional insights not possible in the survey.

Literature Review

Literature was collected primarily from screening relevant websites and through library scans on keywords such as “roadside revegetation” and “native revegetation.”The project team researched various public institutions, State transportation departments, the Bureau of Land Management (BLM), and NPS for relevant manuals and policy and guidance documents. Information, including manuals, policy, reports, and case studies from these and other agencies, was also collected. The project team also recorded other research reports that have cited Roadside Revegetation (see section entitled End Users’ Adoption of Roadside Revegetation Practices).(1)

Website Visitation Analysis

The website for Roadside Revegetation is www.nativerevegetation.org.(4) FHWA’s Western Federal Lands (WFL) has been using Google® Analytics™ to track website visitation statistics since January 2010. WFL provided the project team with historical Web statistics for all dates between January 1, 2010, and February 17, 2015. The visitation statistics summary report for the Roadside Revegetation website includes the following five sections:(4)

WFL/USFS Correspondence

The staff from WFL and USFS who drafted Roadside Revegetation and content for the associated website noted to the project team that much of the feedback regarding the guidance materials had come in the form of personal anecdotal interaction or correspondence from end users.(1, 4) Recent examples of emails from Roadside Revegetation end users were provided to the evaluation team. These emails offer insights about the perceived quality and effectiveness of the guide and Website. 2

Online Survey

From April 1, 2015, to approximately July 31, 2015, the project team administered an online survey of Federal agencies (appendix A) and offices or units that may have implemented Roadside Revegetation practices.(1) The project team re-opened the survey between March 1 and March 15, 2016, to encourage additional responses from FHWA. End users were expected to be staff from FLMAs, State and local transportation departments, tribal governments, FHWA division offices, and other Federal agencies and administrations that may have contracted out revegetation projects.

The survey asked questions regarding the level of awareness of Roadside Revegetation and its website, the extent to which stakeholders have adopted the practices described in the guide, and how effective the changed practices have been in achieving the establishment of native plants and other positive outcomes along roadsides (see appendix A).(1,4)

Telephone Interviews

The project team selected respondents for interviews based on responses to the online survey. The project team contacted 10 respondents to invite them to participate in a follow-up telephone interview. Four individuals participated in follow-up calls. The interviews built on the online survey, asking in-depth questions related to the respondents’ experiences using native plants and their end results. Calls were conducted using a standard interview guide that provided consistency across interviews (see appendix B), and interviewees shared a wide range of thoughts on the subject material and Roadside Revegetation itself.(1) The project team documented the interviews in detailed notes.

2.2 Data Limitations

There are no data limitation concerns regarding the literature review and the website visitation statistics.(4) Regarding email correspondence to FHWA and USFS, a minor limitation relates to feedback collected. FHWA and USFS may not have not tracked all of the email, telephone, and in-person feedback on Roadside Revegetation that they have received.(1) Of the feedback tracked, all example anecdotes provided to the evaluation team reflect positively on Roadside Revegetation. This does not mean that FHWA and USFS selectively tracked feedback, but there may have been end users who had unfavorable views of the guide but who did not provided their input to FHWA and USFS.

In terms of the survey, its results present the following three limitations:

1 Bounce rate is defined as the percentage of single-page sessions. It represents the percentage of visitors who enter and leave a site after viewing one page versus continuing on to view additional pages within the same site.

2 The project team received a series of internal emails from FHWA and USFS from Roadside Revegetation end users. The project team used these emails for the analysis.(1)




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