SUMMARY

Management Practices for Ancillary Transportation Assets

Starting with the 2012 Moving Ahead for Progress in the 21st Century (MAP-21) Act, asset management programs were mandated to be performance- and outcome-driven. Subsequent reauthorization acts have continued to emphasize a performance-based approach for pavements and bridges. This synthesis report documents how departments of transportation (DOTs) manage ancillary transportation assets, including those managed via performance-based approaches. Recognizing the value of managing a broader range of assets beyond pavements and bridges, many DOTs are developing dynamic inventories of various ancillary assets in their Transportation Asset Management Plans (TAMPs). However, these approaches vary and present challenges, which are discussed in this synthesis. The ancillary assets considered in the scope of this synthesis include:

• Hydraulic structures (e.g., culverts, drainage systems).
• Overhead sign and signal structures and signal systems.
• Bicycle and pedestrian infrastructure (e.g., sidewalks and curb ramps).
• Intelligent transportation systems and communications infrastructure.
• High mast and highway light poles.
• Traffic barriers (e.g., guardrail).
• Earth retaining structures.
• Sign panels and supports.
• Building facilities.
• Pavement markings.
• Pavement markers.

Transportation asset management has significantly evolved, expanding beyond the traditional focus on pavements and bridges. DOTs are increasingly recognizing the value of managing ancillary assets, such as signage, lighting, and drainage structures, which are crucial for the overall functionality and safety of transportation networks. In response, DOTs across the country are incorporating these ancillary assets into their asset management frameworks, both formally and informally in their TAMPs. This shift represents a strategic move towards a more comprehensive infrastructure management approach, acknowledging the interconnectedness of various assets and their collective impact on transportation system performance.

The purpose of this synthesis is to explore emerging practices and strategies used by DOTs to manage ancillary assets under their TAMPs or through informal practices. By examining the evolving landscape of asset management, this synthesis aims to provide insights into the challenges, opportunities, and experiences associated with integrating ancillary assets into asset management frameworks. The objective is to document the practices used by DOTs to manage selected ancillary transportation assets, including the levels of maturity and

variability of practice across DOTs. Information for this synthesis was gathered through a literature review, a survey of DOTs, and case example interviews with California, Colorado, Maryland, Minnesota, and Tennessee DOTs.

The literature review indicates that there is support and guidance for managing ancillary assets, although practices vary by state. While few academic references specifically address the management of ancillary assets, national guidance does exist. Various reports, documents, manuals, and websites from DOTs, the FHWA, and AASHTO were reviewed. The literature review also points to the potentially impactful technologies that are being implemented at DOTs. The literature suggests that building information modeling (BIM), 3-D models, digital twins, and artificial intelligence can provide improved efficiency to asset management. However, to capitalize on these benefits DOTs would potentially need to expand and enhance their asset management programs around ancillary assets. The findings of the literature review are presented in Chapter 2. Based on this review and the scope of work for this synthesis, a survey questionnaire was developed.

To collect the most current information on practices and guidelines, including maturity levels and variabilities across DOTs for managing selected ancillary transportation assets, a web-based survey was distributed to the Transportation Asset Management Community of the AASHTO Committee on Performance-Based Management, which includes representatives from all 50 states, the District of Columbia, and Puerto Rico. The findings in this chapter are based on responses from 43 DOTs (an 83% response rate). Of the 43 DOT respondents, 30 DOTs indicated they include ancillary assets in their transportation asset management programs. Of these, 27 DOTs indicated which ancillary assets were incorporated into transportation asset management programs. The commonly managed ancillary assets are presented in Table S.1.

The DOT survey respondents were asked how ancillary assets and their performance measures were evaluated given the following response options:

• Inventoried (condition/performance is determined).
• Performance measured and compared to targets (condition/performance compared to agency goals with consideration of short-range planning).
• Performance measured and forecast for trends (conditions/needs are projected for long-range planning).

Respondents were able to select any combination of the above options (e.g., a respondent could indicate they inventory an asset and compare its performance to targets for short-range planning). Respondents could also provide no response. The 26 DOT respondents selected the inventoried assessment method as the most frequently used for assessing and

Table S.1. Commonly managed ancillary assets.

Table S.2. Ancillary assets commonly assessed via the inventoried assessment method.

evaluating ancillary transportation assets. The more commonly inventoried ancillary assets are listed in Table S.2.

Even with more advanced management methods not being commonly selected, the 26 DOT respondents noted the top five benefits of managing ancillary transportation assets:

1. Accessible condition reporting (19 of 26 DOT respondents, 73%).
2. Accessible inventories (19 of 26 DOT respondents, 73%).
3. Reduction in risk (17 of 26 DOT respondents, 65%).
4. Efficiency in budgetary planning (i.e., planning for funding requests) (16 of 26 DOT respondents, 62%).
5. Improved safety (16 of 26 DOT respondents, 62%).

Finally, DOT respondents indicate having a high priority for adding hydraulic structures [e.g., culverts, drainage systems (7 of 23 DOT respondents)], earth retaining structures (5 of 23 DOT respondents), and traffic barriers [e.g., guardrails (5 of 23 DOT respondents)] to their DOT asset management programs. However, more than half of the responding DOTs (28 out of 35 DOT responses, or 80%) do not plan to include ancillary assets in the next version of their TAMP.

In further detailed case example interviews, feedback suggests there is a desire for increased standardization and availability in performance metrics. All interviewees also noted the value of managing ancillary assets in a structured approach. Transparency and efficiency were the key benefits noted. These benefits, and those noted from the survey responses, present compelling support for, and noted value in, managing ancillary assets. For example, case example interviewees noted the benefit of rightsizing budgets and planning efficiency for managing ancillary assets. Also, the feedback points to potential risks associated with not managing transportation ancillary assets. Stemming from these conversations and data collected, areas for future research were identified.

This synthesis points to a need for guidance in standardized ancillary asset performance metrics and models for condition forecasting. This need is coupled with research needs in condition and deterioration models and metrics for ancillary assets. Additionally, there is a potential need for research around the implementation of emerging technologies as well as the impacts of advances such as BIM in managing ancillary assets.

The following report details the state of practice for the management of ancillary assets by DOTs.