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A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan (2023)

Chapter: Chapter 2 - Defining and Categorizing Maintenance Activities

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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 10
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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 11
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Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 12
Page 13
Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 13
Page 14
Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 14
Page 15
Suggested Citation:"Chapter 2 - Defining and Categorizing Maintenance Activities." National Academies of Sciences, Engineering, and Medicine. 2023. A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan. Washington, DC: The National Academies Press. doi: 10.17226/27291.
×
Page 15

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7   Defining and Categorizing Maintenance Activities The Lack of Consistency in Defining Maintenance Maintenance is an integral aspect of managing a highway network. Even so, the range of activities considered to be maintenance makes it difficult to establish a single definition that works for all agencies. There are some activities that most, if not all, agencies would agree are part of maintenance. These include sealing cracks in pavements or bridge decks, patching potholes, or cleaning culverts. Other activities may be considered maintenance by some organizations but not others. For example, one agency may consider pavement overlays to be maintenance. Another may only consider pavement main- tenance to consist of repairing localized surface distresses. Some maintenance activities depend on an agency’s location or climate. For example, the cost of snow and ice treatments does not apply to all agencies. Additionally, some states that are responsible for snow and ice activities may consider these to be operational costs and not maintenance. The variety of actions and their related costs that could be considered maintenance are influenced by the immediacy of the work, the ability to apply the treatment without design work, and workforce skills. Of the five work types defined by 23 CFR 515.5 for inclusion in state TAMPs, main- tenance is the only one that applies to all stages of an asset’s life cycle. New assets may receive preventive maintenance to delay the onset of distress. As assets are exposed to traffic loadings or if the elements are damaged, they may be repaired or have components replaced through maintenance actions. At the end of an asset’s service life, maintenance treatments, such as pothole patching, may be applied to keep the asset functioning safely and at an accept- able level of service (LOS) before major rehabilitation can be scheduled. In some instances, maintenance may be defined based on the budget cate- gory from which the expenditure is funded or by the organizational unit that delivers or oversees the work. Iowa DOT, for example, includes only work funded through its field maintenance budget in the TAMP investment strategy under the maintenance work type. While contractors may deliver the same activities, those contract costs are included in the preservation work type. This results in similar work being included as both maintenance and preservation, depending on whether the work is delivered by state crews or by contract (Iowa DOT 2019). The variability in what is considered bridge maintenance is even more complicated than it is for pavements. For bridges, the amount of work or the number of similar repairs may be what C H A P T E R 2 Maintenance practices are not defined consistently between agencies or even within a single agency. This causes challenges for agencies interested in connecting activity costs to performance and risk reduction. Incorporating maintenance costs into a TAMP benefits from efforts to define maintenance activities and related expenses consistently within the agency. This starts with identifying a maintenance strategy for each asset class to determine the types of maintenance activities required and the data needed to manage those activities. It is this connection that supports the incorporation of maintenance costs into asset management analyses and a TAMP. To support these efforts, this chapter introduces five maintenance activity categories.

8 A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan differentiates work between maintenance, preservation, or rehabilitation. An example of this is Nevada DOT (NDOT), which identifies “minor structure repair” to be maintenance and “major structure repair” to be rehabilitation. The line between minor and major repairs can depend both on the type of repair and the amount of overall repair work being conducted. Standardization of the activities or expenditures that should be included in the maintenance work type could allow states to better understand how to incorporate those activities and their related costs into a TAMP. A standard could also support communication between agencies. However, standardization, either through guidance or regulation, would limit each agency’s flexibility to describe the specifics of its maintenance program since every agency would be forced to comply. A standard definition would also lead to challenges as new maintenance activities are introduced. Strategies for Maintaining Assets Both asset management and maintenance involve managing asset conditions and performance at all stages of the asset life cycle (see Figure 2-1). Since maintenance can be applied at all asset life-cycle stages, it is important to appropriately consider maintenance activities as an integral part of life-cycle strategies such as preservation and rehabilitation or replacement. Establishing life-cycle strategies that consider maintenance © 2017 Applied Pavement Technology Figure 2-1. Asset life cycle and work types.

Defining and Categorizing Maintenance Activities 9   allows agencies to better understand the comprehensive set of strategies needed to extend asset service lives while minimizing long-term costs. FHWA’s Handbook for Including Ancillary Assets in Transportation Asset Management Programs (Allen et al. 2019) describes three approaches to establishing maintenance strategies to support asset management. Additionally, some agencies have begun managing assets based on risk, creating the fourth approach. The four approaches (or strategies) are listed and summarized in Figure 2-2. These four maintenance strategies define how and when specific activities best support asset conditions and system performance while minimizing the risk or impact of asset failure. This understanding serves as the basis for influencing the types of information and level of detail needed to manage an asset, as explained in the next sections. Condition-Based Management Condition-based management activities are driven by asset conditions. This approach requires the collection of reliable inventory and condition information over the asset’s service life. This data is used to develop mathematical models to estimate asset deterioration. The models are then used to predict future asset conditions to evaluate the type and timing of various maintenance actions based on performance, risk, and costs. For major assets such as pavements and bridges, this can involve computerized asset management systems that are either custom developed or configured from commercial off-the-shelf software. For ancillary assets such as overhead sign structures, culverts, or Americans with Disabilities Act (ADA) appurtenances, conditions may be tracked and modeled using simpler spreadsheet or database tools. SOURCE: Adapted from NASA 2008. Figure 2-2. Components of a reliability-centered maintenance program.

10 A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan Interval- or Age-Based Management Interval- or age-based strategies do not require knowledge of the asset’s condition to schedule and deliver maintenance. Instead, maintenance is delivered at specific times based on a suggested interval. Examples of interval maintenance include culvert cleaning or routine radio tower main- tenance. However, interval-based maintenance can also be used for unit replacements for safety- critical assets and those with highly uniform service lives. Safety-critical assets may require replacement before a given level of deterioration has occurred. Sign panels are an example of a safety-critical asset with a highly uniform service life. Interval-based maintenance may also be appropriate for assets with very short service lives, such as pavement markings. Reactive Management Reactive management delivers maintenance after the asset’s condition has deteriorated below an acceptable level, usually unexpectedly. Some forms of reactive maintenance are necessary for all assets, such as repairs needed in response to emergencies or vehicle collisions. However, some assets may be entirely managed reactively, from initial construction until replacement. Reactive management is typically used for assets with long service lives and minimal preventive maintenance or repair options. Examples of assets managed reactively are guardrails and gravity retaining walls. Although reactive maintenance is often due to unexpected conditions, it may also be triggered by ongoing condition monitoring. This type of reactive management is similar to condition-based management, except the only condition-based trigger is when the asset deteriorates below an acceptable level of condition. Risk-Based Management Risk-based management is employed when the potential impact on the system performance from a failure of the asset, rather than the asset’s condition, drives the identification and pri- oritization of work. In these cases, the risk of asset failure, measured in terms of likelihood and potential impact, is the driving concern for the agency. Geotechnical assets are commonly managed using a risk-based approach. This approach requires routine assessment of the asset and its related risks. The Implications of Selecting a Maintenance Strategy The management strategy selected for an asset will have a direct bearing on the activities performed to maintain the asset class, the data needed to manage the asset, and the level of effort required to identify and schedule needed work. Effective maintenance management involves collecting many different types of data for each asset class. However, agencies will want to mini- mize the collection of data that is not used for decision-making or risk mitigation. Depending on the management strategy selected, certain types of data are essential, while other data is not required but may be beneficial. Agencies may choose to collect additional, nonessential data to further refine maintenance decisions or support other program needs beyond maintenance. A condition-based approach demands the routine, ongoing collection of reliable condition data. A risk-based approach needs sufficient data to understand the risk of failure and the potential impact if a failure occurs. Based on these data needs, agencies should carefully consider whether they have the resources needed to ensure that the data is updated and maintained over time. It is important that the data’s purpose is understood to ensure that the data format and quality are matched to the intended purposes. If the data’s purpose is unclear, data collection costs may

Defining and Categorizing Maintenance Activities 11   exceed the value provided for decision-making. In general, condition- and risk-based approaches require the highest levels of data and data quality. Each agency must balance data collection costs and benefits to determine which elements to collect, how often, and the degree of accuracy needed. The FHWA Handbook for Including Ancillary Assets in Transportation Asset Management Programs provides recommendations on the type of data needed to manage assets based on the selected maintenance approach, as summarized in Table 2-1. Categorizing Maintenance Activities Once the appropriate maintenance approach has been selected for each asset, an agency has to determine which maintenance activities will be categorized as maintenance and which will be classified as preservation or rehabilitation/replacement. The framework outlined in this Guide provides flexibility in categorizing activities as maintenance to accommodate the unique needs of each agency. Scalability is also accommodated so the guidelines can be applied to any high- way asset. The Guide defines five different maintenance categories for use in grouping costs for TAMP development. Each is described in Table 2-2. They provide the necessary flexibility and scalability to accommodate the needs of most agencies in categorizing different types of maintenance costs. The following are the five maintenance categories: • Operations and routine maintenance. • Preventive maintenance. • Repair. • Unit or major component replacement. • Organizational strengthening. An important factor used in developing the five maintenance categories is their impact on the following TAMP processes required under 23 CFR 515: • Performance gap analysis—23 CFR 515.7(a). • Life-cycle planning (LCP)—23 CFR 515.7(b). • Risk management—23 CFR 515.7(c). • Financial planning—23 CFR 515.7(d). • Investment strategies—23 CFR 515.7(e). The primary factor for how an activity impacts these processes is based on the activity’s effect on asset condition, service life, and risk. Understanding which maintenance activity category applies helps an agency incorporate each activity’s costs and benefits appropriately into TAM processes that are used to develop a TAMP. Table 2-2 describes the impact each maintenance activity category has on asset condition and risk. It also describes the consideration of each category in terms of funding sources and investment strategies. Maintenance Approach Condition-Based Yes Yes Yes Yes Yes Optional Interval-Based Yes Yes Yes Optional Yes Optional Reactive Yes Yes Yes Optional Optional Optional Risk-Based Yes Yes Yes Optional Optional Yes SOURCE: Allen et al. 2019. Asset Type Asset Location Unique ID Condition Data Age/Last Treatment Risk Data Table 2-1. Essential data to collect for each maintenance approach.

12 A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan Operations and Routine Maintenance Activities classified as operations and routine maintenance serve to sustain or restore func- tionality to the highway facility but do not impact measurable asset conditions. As such, these activities do not play a significant role in LCP other than in appropriately budgeting for their costs. Examples of operations activities include incident management and snow and ice control. For operations and routine maintenance activities with costs tied to asset conditions, it is important that forecasts of these costs be integrated with LCP for the asset in question. How- ever, since these costs do not typically change the life-cycle strategies, they are not essential to an LCP analysis. Instead, these activities are best addressed through financial planning as fixed costs, i.e., factors influencing the amount of funding available for activities that improve asset conditions. Routine maintenance includes a range of activities both on the roadside and in travel lanes, such as mowing, litter removal, and graffiti removal. Routine maintenance supports the safe and effective operations of the highway system but does not impact asset conditions. Maintenance Activity Category Impact on Asset Conditions and Risk Operations and Routine Maintenance Restores or sustains functionality but does not impact asset conditions (e.g., road patrol, mowing, and snow and ice control). Does not impact LCP and addressed as fixed-cost items that reduce the amount of funding available for activities that improve asset condition. Typically funded from operations budget. Preventive Maintenance Prevents or addresses deterioration to delay a decline in measured conditions but does not significantly improve conditions (e.g., crack seal, chip seal, sweeping, drain cleaning, bridge washing). Because of its impact on future conditions, this should be incorporated into the LCP. Can be listed as maintenance or preservation work type and accounted as maintenance or capital improvement costs. The same activity may be defined as maintenance and preservation based on the budget category from which the expenditure is funded or by the organizational unit that delivers or oversees the work. Repair Repairs damage or deterioration. Improves measurable condition and function but does not restore or improve structure, capacity, or functionality (e.g., mill and inlay, deck repair). May include replacement of parts but not major components. Can be listed as maintenance, preservation, or rehabilitation work type and accounted as maintenance or capital improvement costs. The quantity of repair, rather than the type, generally qualifies the activity as maintenance. Repairs may also be difficult to discern from routine maintenance. Unit or Major Component Replacement Replaces one or more individual asset components, restoring functionality for that component (e.g., sign panel replacement, striping, traffic signal component replacement). Can be listed as maintenance, rehabilitation, or reconstruction work type and accounted as maintenance or capital improvement costs. For some assets, the entire asset may be replaced under a maintenance action because of the mechanism by which the replacement is delivered or funded. Other assets may be tracked individually, and the replacement of individual components may be considered maintenance. Organizational Strengthening Involves maintenance activities that are not directly asset-related. Activities may mitigate risk or improve organizational capacity (e.g., training, safety briefings, These maintenance activities can be budgeted “above the line” so that stakeholders and decision makers can see what activities are planned to strengthen the capabilities and the culture of the management system use, planning, supervision). maintenance organization. These activities can be tracked using the time, labor, and material features in a maintenance management system. Funding Source and Investment Strategy Table 2-2. Maintenance activity categories.

Defining and Categorizing Maintenance Activities 13   Operations activities are conducted to keep the highway system operating safely and effec- tively. Often, operations and maintenance are funded from the same sources and conducted by the same staff. Operations activities have no impact on asset conditions or service lives. However, operations activities may be closely related to asset management risks and the mitigation of those risks. Activities such as incident response, emergency response, and winter maintenance are examples of operations activities. Road patrol inspections may also be considered an opera- tions expense. Preventive Maintenance Preventive maintenance mitigates or hinders deterioration and aims to delay a future decline in measured conditions. Preventive maintenance often does not have an immediate impact on measured conditions since it is designed to prevent or slow future deterioration. For example, crack sealing does not eliminate a crack, but it does slow crack propagation. Many cleaning and sealing activities can be described as preventive maintenance. Since preventive maintenance has an impact on asset conditions, it should be incorporated into LCP. Preventive maintenance on ancillary assets can often be conducted concurrently with inspec- tions. For example, during an inspection of a traffic signal cabinet, the inspector may clean components, replace a weatherproof seal, or perform other preventive maintenance activities. The inclusion of preventive maintenance activities in pavement and bridge management systems is not always straightforward. For example, agencies do not always know where in-house crews have applied preventive maintenance treatments (Peshkin and Duncan 2021). A second challenge corresponds to the difficulty in modeling preventive maintenance treat- ment performance since these treatments are used in both preventive and reactive manners. Therefore, the same treatment may exhibit different performance depending on how the treatment is being used. An example of this dual use is in thin pavement overlays. They may be applied to address minor surface distress and extend pavement life. They may also be applied as a low-cost patching alternative to extend the service of heavily distressed pavements. While the latter use is not typically considered cost-effective from an LCP perspective, it may be a practical solution. It should also be noted that when such overlays are applied at the end of a pavement’s life, they are used as routine maintenance, not preventive maintenance. Agencies can overcome this challenge by considering the pretreatment condition of the asset when developing perfor- mance models. Repair Maintenance repairs preserve asset conditions by addressing specific defects to improve measurable conditions and restore function, but they do not improve structure or capacity. Repairs are the category of maintenance activity that overlaps most with the TAMP work types of preservation or minor rehabilitation. In general, maintenance repairs are smaller and more localized than global rehabilitation treatments. Many types of repairs are common to pavements and bridges. It is often the quantity of repair, rather than the type, that will qualify the activity as maintenance. For example, if a single bridge element is repaired, it will likely be considered maintenance. However, if all the elements of a given type are repaired on a bridge, it will likely be considered rehabilitation. Repairs may also be difficult to discern from routine maintenance. For example, permanent pavement repairs can be difficult to distinguish from pothole patching. The primary differentia- tor between repair and routine maintenance, in this case, is that pavement repairs measurably improve the condition of the asset, whereas routine maintenance activities do not.

14 A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan For ancillary assets, repairs will typically replace parts or elements to return the asset to service. Examples of this include repairing guardrails after a collision or replacing a traffic signal or Intelligent Transportation Systems (ITS) elements. Emergency repairs are a special subset of the repair category. Emergency maintenance activities are generally unplanned repairs that are undertaken in response to sudden or unforeseen events such as asset failure, serious damage, or a drastic reduction in LOS. For example, repairs on assets that have been damaged by flooding would be categorized as emergency maintenance. Costs for emergency work do not contribute to improving asset conditions, so they are not considered in life-cycle and asset-preservation planning. But their costs may be treated as a line item in recognition of their contribution to system resilience and risk reduction. Unit or Major Component Replacement Unit or major component replacement recognizes that not all replacement activities rise to the level of reconstruction. Some assets are replaced through maintenance activities without reconstruction. With some assets, such as sign panels, the entire asset may be replaced under a maintenance action because of the mechanism by which the replacement is delivered or funded. Comparably, ITS and signal components, such as controllers or cameras, may each be tracked individually, and the replacement of individual components may be considered maintenance. Organizational Strengthening Transportation agencies often list their employees as their most important resources, but maintaining human resources can often be overlooked organizationally. Organizational strength- ening is a maintenance category that considers the positive impact of human resources on the overall maintenance of the organization’s culture and performance. These activities may have been considered simply as overhead expenses in the past; however, from an asset management standpoint, these activities make the employees and organizations more resilient and mitigate risks that may be identified in an agency’s risk register. Many agencies budget for these main- tenance activities “above the line” so that stakeholders and decision makers can see what activ- ities are planned to strengthen the capabilities and the culture of the maintenance organization. These activities can be tracked using the time, labor, and material features in a maintenance management system. This approach recognizes organizational strengthening activities to be comparable to other maintenance activities, such as pothole patching or drainage correction activities. This approach is feasible since maintenance time records interface directly with an agency’s enterprise payroll system. Different types of organizational strengthening expenses are described further. Management and Administration These activities involve the planning, design, scheduling, and support of the activities described in the prior categories and are almost entirely supervisory responsibilities. Additionally, they are normally performed to support the overall maintenance program, so the costs are usually accounted for through an overhead rate that is applied to labor costs. Agencies need to review their labor charges periodically to ensure all management and administration costs are accounted for. While some organizations may not consider work planning or safety briefings that occur at district offices or maintenance sheds as a strengthening activity, capturing these costs makes it possible to show that organizational goals are being met, and risk is being mitigated.

Defining and Categorizing Maintenance Activities 15   Training Training maintenance workers is essential to ensuring the maintenance organization can deliver work safely, effectively, and efficiently. In some cases, training may be required for job retention or promotion. For example, New York State DOT (NYSDOT) requires new highway maintenance workers to complete training for the solo operation of a snowplow, or “one-person plowing.” Effective and ongoing training on maintenance best practices is also key. Materials, equipment, and techniques are continually changing and advancing, and the cost of training can be offset by improved productivity and work quality. Training may also be essential as agencies recognize the need to add new skills or activities to their maintenance programs. For example, an agency may determine it is more cost-effective to train its internal workforce to perform specialized work than to use contracted resources. Emergency Preparedness Agencies capture their efforts for emergency preparedness and show these activities as a way to make the organization more resilient during a disaster or in preparation for responding to disasters. Technology Agencies may adopt technology that strengthens their maintenance practices, including automatic vehicle location, local entry of data into the maintenance management system, or automated data gathering for maintenance quality assurance performance metrics.

Next: Chapter 3 - Data to Support Integrating Maintenance into a TAMP »
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Since 2018, State departments of transportation (DOTs) have been required to develop risk-based transportation asset management plans (TAMPs) and to update processes for developing these plans every four years. To date, several DOTs have described challenges in showing clear connections between maintenance investments and asset condition.

NCHRP Research Report 1076: A Guide to Incorporating Maintenance Costs into a Transportation Asset Management Plan, from TRB's National Cooperative Highway Research Program, leads practitioners through a six-part framework designed to tackle the biggest challenges agencies face in projecting future maintenance costs in TAMP activities. Supplemental to the report is a pocket guide.

Supplemental to the report are NCHRP Web-Only Document 372: Incorporating Maintenance Costs into a Transportation Asset Management Plan, an Executive Summary, an Implementation Memorandum, an Overview Presentation, and a Publication Announcement.

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