CHAPTER 2 Research Approach

2.1 Literature Review and Nationwide Surveys

The literature review synthesized information found within both published and unpublished (white and gray) domestic and international articles. The research team focused on tools and technology that can assist with tracking work progress, asset conditions, and equipment, and technology that can assist with remote and manual mapping. The team researched tools and technology for both vegetation and structural assets and found more available information for structural assets than for vegetative assets during the literature review. Tools and technology determined to be appropriate for vegetative assets, regardless of their original purpose, were described within the literature review (Appendix A).

After completing the initial research for the literature review, the research team developed questions for two nationwide surveys. The TRB project panel reviewed all questions prior to the surveys’ launch. These surveys were sent approximately one month apart from each other and requested information on different topics for RVAM. An introduction letter was included with both of the surveys which defined RLAM (the term being used at the time), tools and technology, and the length of time included within the term “new” for the purposes of the survey. Rasor Communications and Marketing, a marketing and communications firm, distributed both surveys via email with a link to an online survey platform. Information collected during both surveys informed further research needs during the literature review and helped determine the state DOTs to include as case studies.

The initial survey was open for three weeks and included twenty-six questions regarding basic RVAM practices. This survey was emailed to forty-nine state DOTs, two contractors, and seventeen utility companies. The list of state DOT contacts was developed with the project panel and included DOT maintenance directors. Every state DOT for which an email address could be sourced by the TRB project panel was contacted during this survey. The research team developed the list of utility recipients, and the TRB project panel reviewed the names prior to distributing the survey. This methodology resulted in twenty-eight total responses (Table 1), with twenty-seven of those from state DOTs. Three reminders were sent to organizations that had yet to complete the survey as indicated in Table 1 below.

Table 1: Initial Survey Contact Date and State DOT Responses.

Following the closure of the initial survey, the research team reviewed responses and sent the second (targeted) survey to those organizations with an RVAM plan. The targeted survey was open for two weeks. Within this time, sixteen of the twenty-three state DOTs contacted responded (Table 2). No utilities or contractors were contacted for the targeted survey, as only one utility company responded to the initial survey.

Two reminders were sent during the targeted survey. The targeted survey included many questions designed for asset management staff, information technology (IT) staff, and general management staff, among others.

Table 2: Targeted Survey Contact Date and State DOT Responses.

2.2 Case Study Determinations

The research team used the survey responses to create a determination table to inform a decision as to which state DOTs to include as case studies. The research team met with the NCHRP panel following survey completion to discuss survey results and determine which state DOTs to invite to participate as case studies. The state DOTs that were included as case studies can be found in Table 3.

The TRB project panel met with the research team to determine which state DOTs would be beneficial to participate in the development of the Guidebook based on the tools and technology each DOT currently uses as described in the nationwide surveys and to choose a geographically diverse selection of states. Following this meeting, DOTs were contacted, and scheduling began. During this process, three of the six state DOTs initially contacted were unable to participate due to staff workloads. At this point, the team contacted two additional state DOTs to ensure five case studies would be completed. The case studies encompassed various geographic regions of the US and various stages of RVAM development. Case studies were developed for the Guidebook with the following state DOTs in the fall of 2023: California (Caltrans), Ohio (ODOT), Tennessee (TDOT), Wisconsin (WisDOT), and Washington State (WSDOT) (Table 3).

Table 3: DOTs Selected for Case Studies.

The research team suspected that many of the state DOTs with an RVAM plan that responded to the surveys have more advanced technology than other DOTs that did not respond to the survey. As such, to ensure representation for all states, the research team ensured some of the state DOTs selected for the RVAM case studies had tools and technology that had not been recently updated. For some state DOTs, this included in-house management systems that had not been updated in ten-plus years; for others, it was a lack of technology or staff access to technology. By including state DOTs with a wide array of tools and technology in the Guidebook, the research team aimed to illustrate steps to further develop RVAM plans.

2.3 Work Plan for the Guidebook

The research team worked with the project panel to determine the direction of the Guidebook and created an outline using information collected through the literature review, nationwide surveys, and case studies. This was submitted to the TRB project panel for review and included anticipated Guidebook sections and example images of graphics, such as charts developed for the Interim Report.

2.4 Interim Report and Technical Memorandum

The research team reviewed the findings from the literature review, nationwide surveys, and case studies to synthesize the tools and technology, effective implementation methods, performance measures, and steps to enable vegetation asset management.

The synthesis, provided in the Interim Report, evaluated the availability of tools and technology, the types of software and hardware available (commercial off-the-shelf (COTS) software, proprietary configuration of commercially available software (PCCA software), or solely proprietary software) for state DOTs, the need for internal support to implement various types of available software, costs of RVAM, hindrances to implementation state DOTs encountered during RVAM system upgrades, security concerns, and funding information.

The Interim Report and Technical Memorandum were delivered to the project panel via the TRB portal and then presented in-person to the project panel in January of 2024. Edits were made to the report and Technical Memorandum as requested, and the TRB project panel received an updated Interim Report for final review in March of 2024. The purpose of the Interim Report was to review project progress and the direction of the next tasks to stay on the project path as outlined at the beginning of the project. The purpose of the Technical Memorandum was to discuss the possible implementation tasks that are recommended after the completion of this project. These implementation tasks are included in the Guidebook as well as listed later in this report. The information that was presented in the Interim Report is included in the Conduct of Research report and the Guidebook.

2.5 Final Deliverables

A draft of the Guidebook and Conduct of Research report was completed and delivered to the project panel for review and approval. The Guidebook provides a path forward for state DOTs to update their tools and technology for RVAM by showing the successes and challenges of other DOTs so each organization can determine their best approach. The Conduct of Research report provides background information on RVAM and how structural asset tracking and mapping can be transferred to RVAM assets.

The final deliverables include a fully developed Implementation Plan and a presentation with slide notes that were delivered to the panel with the final Guidebook and Conduct of Research report. The Implementation Plan provides a pathway for the implementation of the recommendations, including providing guidelines for the creation or use of an already established group to oversee the progression of RVAM through an organization, such as the TRB. The presentation with speaker notes that was provided to the TRB project panel can be used to further RVAM activities nationwide.