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An Asset-Management Framework for the Interstate Highway System (2009)

Chapter: Chapter 5 - Performance Management

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Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
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Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
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Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
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Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
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Page 40
Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
×
Page 40
Page 41
Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
×
Page 41
Page 42
Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
×
Page 42
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Suggested Citation:"Chapter 5 - Performance Management." National Academies of Sciences, Engineering, and Medicine. 2009. An Asset-Management Framework for the Interstate Highway System. Washington, DC: The National Academies Press. doi: 10.17226/14233.
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36 This section describes the performance management approach recommended as part of the Interstate Asset Man- agement Framework, and identifies core and comprehensive performance measures for managing IHS assets. In this study, “core” measures are performance measures that any IHS owner agency should, in theory, be capable of capturing and should appear in any Interstate Asset Management Plan. It is recommended that IHS owners collect the additional “compre- hensive” measures described here, pending time and resource limitations. Section 5.1 provides an overview of the role of performance measures in asset management. Section 5.2 summarizes the approach used to evaluate different potential measures for IHS asset management. Section 5.3 details the recommended core and comprehensive performance measures. Section 5.4 identi- fies the most significant gaps related to defining a set of per- formance measures for characterizing the IHS assets. 5.1 Overview Performance measurement, defined as “the use of statistical evidence to determine progress toward specific defined organi- zational objectives . . . ,” (23) is a cornerstone of transportation asset management. Performance management encompasses the development of a set of measures for characterizing the per- formance of an organization, setting specific targets or goals for those measures, and monitoring the organization’s progress in meeting those goals. In recent years, much attention in the transportation com- munity has been paid to adapting performance management concepts originally developed in the private sector for use in improving transportation management. Defining performance measures is a key step in implementing an asset management approach. Once performance measures are defined for an organization, they help support asset management in three basic ways. First, performance measures can be used to quan- tify policy goals and objectives in a practical way. For example, Oregon DOT translates agency goals into specific performance measures in its annual performance progress report. Figure 5.1 provides an example for this report, depicting traffic fatalities per 100 million of vehicle miles traveled over time (2001 to 2006). The figure also shows agency targets set for this measure in support of the goal of improving travel safety in Oregon. The second basic use of performance measures is to help evaluate different options in the resource allocation process, such as for determining how to prioritize different invest- ments and/or comparing the impact of different funding lev- els. Figure 5.2 is an example from the pilot performed for the current study. For a sample interstate corridor, the figure shows predicted Pavement Quality Index (PQI) for different annual budget levels. The third basic approach for using performance measures to support asset management is to use performance measures for monitoring progress to provide feedback on the effective- ness of a program, and/or provide information on trends over time. For example, Virginia DOT has established a web-based dashboard for tracking system conditions and performance. Figure 5.3 shows data on IHS pavement conditions from the dashboard application. The dashboard provides details on performance, safety, condition, and finance measures, as well as on customer satisfaction and project delivery. Measures are summarized at a statewide level and broken down by system, county, and district. The motivations for establishing performance measures for asset management are well-understood. However, there are no standard measures defined for managing IHS assets. The remainder of this chapter describes the approach used to evaluate different performance measures for inclusion in the Interstate Asset Management Framework and presents a rec- ommended set of core and comprehensive measures. 5.2 Evaluation Approach Given the importance of performance measures to asset management, a critical activity undertaken as part of this study was to evaluate performance measures that can be used to C H A P T E R 5 Performance Management

37 Figure 5.1. Use of performance measures for quantifying goals. Source: Oregon Department of Transportation (24). Figure 5.2. Use of performance measures for evaluating options. characterize IHS assets, and on the basis of the evaluation, recommend a set of performance measures to include in the Interstate Asset Management Framework. A key resource in structuring and performing the evaluation was NCHRP Report 551, which details a review of existing practices related to per- formance management, and provides guidance for establish- ing a set of measures (4). Figure 2.4 provides a framework for establishing performance measures and targets for asset management. The approach to developing a set of perfor- mance measures for use in reporting IHS conditions in an Interstate Asset Management Plan has been adapted from this framework. As indicated in Figure 5.4, identifying

performance measures involves five basic steps. The following is a description of the activities performed for each of these. Step 1—Review Existing Measures A review of the performance measurement literature was performed, as detailed in Appendix A. The review started with the materials compiled by the research team previously and summarized in NCHRP Report 551 (4). These materials were supplemented with more recent materials and examples of measures reported at a national level and/or measures of con- dition or performance that can be calculated specifically for the IHS. Based on the review, a master list was compiled of existing IHS performance measures. The list included, but was not limited to: • Measures listed in Measuring Performance Among State DOTs (26); • Quality-of-service measures from the Guide to Effective Free- way Performance Measurement (18), including measures in the areas of Congestion, Reliability, Throughput, Customer Satisfaction, Safety, Ride Quality and Environment; • Interstate measures included in the FHWA C&P Report (27); • Highway-related measures listed in the U.S. DOT Fiscal Year 2006 Performance and Accountability Report (28); and • Additional measures identified through the review. Step 2—Assess Needs The focus of this step was on defining how and why perfor- mance measures should be used for supporting the Interstate Asset Management Framework described in Chapter 2. Defin- ing a set of performance measures is not an end in itself, but a means to support asset management using the approaches described in Section 5.1: quantifying policy goals and objectives; facilitating evaluation of options; and monitoring progress. In this step the research team considered what types of measures are needed for supporting asset management, and how well the existing measures compiled in Step 1 provide this support. Five basic categories of measures were established for sup- porting the Interstate Asset Management Framework. These categories include: • Preservation—Measures in this category characterize the physical condition of transportation assets; • Mobility—This category describes how well the transporta- tion network is performing its basic function of support- ing transport, and includes measures of throughput and congestion; • Safety—This category includes measures of crashes and fatalities, as well as other measures related to safety; • Environment—Measures in this category characterize the environmental impact of the IHS, and the degree to which an IHS owner is meeting its environmental goals; and 38 Figure 5.3. Use of performance measures for tracking progress. Source: Virginia Department of Transportation (25).

• Project Delivery—Measures in this category describe how well an agency is delivering projects compared to its capital plan. The existing measures identified in Step 1 were organized in the categories listed above. Next a gap analysis was performed to assess issues including: • Do the existing measures address all of the assets on the IHS? As discussed in Chapter 4, large amounts of data are available for pavements and bridges relative to other assets. However, it is important that the framework address all IHS assets. • Considering the underlying reasons for implementing asset management for IHS assets, are there applications for which performance measures may be needed, but for which no measures are identified? • How well do the existing measures align with the available data described in Chapter 4? Note that the availability of data for calculating a measure, or lack thereof, is not in and of itself an indication of whether a measure is needed to sup- port the Interstate Asset Management Framework. How- ever, to the extent there are multiple measures that can be used to characterize a single asset or objective, emphasis was placed on measures that could be calculated given available data. • To the extent there are issues in aligning measures and data, are there supplemental or alternative measures that can be more easily captured and/or that make better use of the available data? • Are additional categories needed to adequately classify per- formance measures that may be needed to support asset management for the IHS? Can any of the categories be consolidated? The result of this step was a supplemented list of perfor- mance measures, organized by category. Also, this step resulted in identification of a number of gaps in the existing set of per- formance measures. These are discussed further in Section 5.4. Step 3—Define Selection Criteria Next the research team established a set of criteria for eval- uating performance measures to be included in the Interstate Asset Management Framework. Criteria used for this step were adapted from NCHRP Report 551 and include: • Feasibility—It should be feasible to collect data for this per- formance measure, and to quantify the performance mea- sure for the IHS. Ideally, the measure can be calculated from Federally mandated data, or other data generally collected for IHS assets, as discussed in Chapter 4. If the data require- ments extend beyond what is widely available for the IHS, this should be noted. • Policy-Sensitive—It should be possible to relate the mea- sure to an agency’s stated policy objectives, and help quan- tify whether the outcome of a policy objective has been achieved. This criterion tends to favor outcome measures that reflect outcomes achieved, versus output measures that quantify the activities performed by an organization. • Supports Long-Term, Strategic View—The measure should facilitate long-term tracking. Ideally, it should be possible to make forecasts of the measure over time to sup- port analyses of lifecycle costs and benefits and to review past performance. 39 Figure 5.4. Performance measure evaluation approach. Step 1: Review Existing Measures Step 2: Assess Needs Step 3: Define Selection Criteria Step 4: Apply Selection Criteria Step 5: Finalize Set of Measures • Perform literature review • Inventory existing measures • Compile list of measures relevant for IHS Asset Management • Evaluate needs for IHS performance measures • Establish performance measure categories • Perform gap assessment • Supplement set of existing measures • Organize measures by category • Feasibility • Policy-sensitive • Supports long-term view • Useful for decision support • Useful across organization and beyond • Evaluate each measure • Group measures by asset/objective • Characterize variations between like measures • Develop initial set • Peer review • Develop recommended set • Distinguish between core and comprehensive

• Useful for Decision Support—The measure should pro- vide information that helps support the decision-making process. It should be collected frequently enough and demonstrate changes clearly enough to reflect impacts of agency actions. Ideally, it should be possible to distinguish between changes in the measure resulting from actions under an agency’s control and external drivers. • Useful Across the Organization and Beyond—The mea- sure should be easily understood and communicated within an organization and to external stakeholders. The measure should function as part of a family of measures that can be used to describe performance at different levels of aggrega- tion (e.g., corridor, state, entire IHS system), different time horizons, and for different audiences. Step 4—Apply Selection Criteria In this step, criteria were applied to the set of measures com- piled previously, including measures identified in Step 1 and additional measures for which a need was identified through the gap analysis performed in Step 2. The result of this step was an evaluation of each of the measures on the basis of the crite- ria described above. After an initial attempt to classify individual measures for each criterion on a high/medium/low scale, the research team found that a more useful approach was to group like measures (e.g., by category and asset), and characterize the variation between members of the group descriptively. For instance, for bridge preservation measures, there are many possible mea- sures of bridge condition, most derived from NBI and/or element-level data described in Chapter 4. Generally speaking, the detailed measures derived from the available bridge data that are most useful for decision support (e.g., element-level conditions) are least useful for communication across and out- side an organization, and most likely to require additional data that may or may not be available consistently from one agency to another. Thus, these measures are best considered as a group, weighing the relative advantages and disadvantages of each of the alternative measures compared to the others. Step 5—Finalize Set of Measures The last step of the process was to finalize the set of perfor- mance measures recommended for the Interstate Asset Man- agement Framework. The research team developed an initial set of recommendations that addressed all of the assets on the IHS and each of the categories identified previously. Where multi- ple measures were available for characterizing a given asset or objective, the research team relied upon the results of Step 4, supplemented with best practice examples, to pare down the list to keep it as short as possible while still providing compre- hensive coverage. Following development of the initial set of measures, a proj- ect workshop was held to review all aspects of the project. This workshop was held in Dallas, Texas in March 2008. Partici- pants included representatives from FHWA, state DOTs, and the private sector, as well as the Project Panel. Based on com- ments received from workshop participants and panel mem- bers, the research team revised the initial set of performance measures and developed the recommended set presented in Section 5.3. Further, the research team distinguished between core measures that in theory any IHS owner should be capable of capturing and should appear in any Interstate Asset Man- agement Plan and additional comprehensive measures. Ideally, every IHS owner would report the core measures described here, at a minimum, and plan in the future for collecting and reporting the full set of comprehensive measures. 5.3 Recommended Measures for IHS Asset Management Table 5.1 details the core set of performance measures rec- ommended for the Interstate Asset Management Framework. Performance measures are organized by category. For each cat- egory, the table lists the asset type, where applicable, as well as the measure type and measure. Table 5.2 lists additional, com- prehensive measures. Note that the measures are intended to characterize overall conditions of the portion of the IHS managed by a given orga- nization, rather than a specific section or the overall transporta- tion network. Additional detailed data are required in every category for making project-level and operational decisions, such as for determining appropriate treatments at the asset level. Additional high-level measures may be useful for evalu- ating the overall state of the transportation network. The fol- lowing paragraphs discuss each category. Preservation. This category includes measures of asset condition for each asset type. For pavements, two measures are recommended: structural adequacy and ride quality. PSR can be used to approximate structural adequacy. However, most agencies have established agency-specific measures that consider rutting, cracking, and faulting. Pending update of the HPMS, these agency-specific measures are preferable to PSR. For characterizing bridge conditions, the percent of bridges classified as structurally deficient (SD) is recommended as the best overall measure available for supporting IHS asset man- agement. Note that the determination of whether or not a bridge is functionally obsolete (FO) is not recommended as a measure of bridge condition, as this measure specifies whether the bridge is designed to current functional standards rather than characterizing its physical condition. Thus, a bridge could be classified as FO but not have any preservation needs. The recommended pavement and bridge measures are tracked and can be predicted using agency pavement and 40

bridge management systems, or alternatively using HERS-ST and NBIAS developed by FHWA. It is important to note that existing pavement and bridge management systems consider multiple objectives and constraints in developing work recom- mendations, and use additional measures and criteria for rec- ommending work besides the measures listed in Table 5.1. The recommended pavement and bridge measures are intended to provide an overall indication of asset conditions, and not intended for use as a tool for prioritizing work or a replacement for pavement and bridge management systems. For other assets beside pavements and bridges, this report recommends calculation of the percent of the asset quantity “functioning as intended” as the measure that can best support the Interstate Asset Management Framework. An important issue in considering the measures in this cat- egory is that of what measures should be considered core ver- sus comprehensive. In reality, all assets on the IHS are of great importance. However, the fact that all assets are important does not necessarily mean that it is vital for an IHS owner to capture and report performance measures for all IHS assets in the near term as part of its Interstate Asset Management Plan, possibly diverting resources from other important activities to do so. Further, it is assumed that IHS owners do now and will continue to address public safety issues (e.g., pending failure of a structure) even in the absence of an Interstate Asset Manage- ment Plan. Thus, the consideration of what assets are core ver- sus comprehensive was based primarily on consideration of asset extent and degree to which data are available. Mobility. This report recommends using travel time index (the ratio of actual travel rate to the ideal rate) and average delay as the best overall measures of mobility. Both measures can be calculated from readily available HPMS data and predicted using HERS-ST, and can be reported by rural/ urban roads, by corridor, and/or separately for autos and trucks. Winter maintenance is included here as a compre- hensive measure in the mobility category, with a measure of average time to bare pavement following a snow event. In cold weather, states’ winter maintenance is a core issue, but is gen- erally not managed by system. Safety. Crash and fatality rates are recommended as the best overall measures of safety outcomes. Typically these are reported in terms of total numbers of crashes and fatalities, and the rate reported as the number per 100 million VMT. Environment. Rather than recommending a specific set of measures as in the other categories, this report recommends a report card approach for the Environment category, whereby an IHS owner establishes a set of environmental milestones, and reports whether they are achieving them on a pass/fail basis. These milestones may include any of the examples listed above, and should include an indication of whether or not the IHS owner is satisfying its environmental commitments. Other. Cost control and schedule adherence are rec- ommended as comprehensive measures of project delivery. Reporting delivery measures is becoming increasingly 41 Table 5.1. Recommended core performance measures for the Interstate Asset Management Framework. Category Asset Type Measure Type Measure Structural Adequacy Present Serviceability Rating (PSR) or an agency’s pavement condition index Pavement Ride Quality International Roughness Index (IRI) Bridges Structural Deficiency Percent classified as Structurally Deficient (SD), weighted by deck area Signs Asset Performance Percent functioning as intended Pavement Markings/ Delineators Asset Performance Percent functioning as intended Preservation Guardrails Asset Performance Percent functioning as intended Travel Time Travel time index Mobility Delay Delay per vehicle in hours Crash Rate Number of crashes expressed as number per year and per VMT Safety Fatality Rate Number of fatalities expressed as number per year and per VMT Environment Agency-specific report card of environmental milestones Pass/fail indication for each measure

common, but is typically done on an overall basis rather than by system. It is not strictly required that consideration of project delivery be handled in an Interstate Asset Manage- ment Plan if an IHS owner handles this issue separately. No measures are recommended regarding security or social impacts, as it is generally not feasible to isolate existing mea- sures to the IHS. However, security and social impacts as well as measures of economic impact may be very relevant in charac- terizing the overall importance of a transportation system and in justifying investments, particularly large investments in additional capacity. Customer satisfaction measures are not included under the assumption that the public is likely to assess the level of satis- faction with the transportation system as a whole, rather than the IHS specifically. 5.4 Gap Assessment The following are the most significant gaps related to defin- ing a set of performance measures for characterizing IHS assets (or transportation assets in general): • There is no national standard for accurately characterizing structural adequacy of pavement. In the absence of such a measure, it is recommended that agencies use an agency- specific index instead or PSR. PSR is reported in the HPMS, but does not consider a full range of pavement distresses. The expected update to the HPMS will add additional measures of pavement condition to the HPMS, and should facilitate standardization of an overall measure of struc- tural adequacy. 42 Table 5.2. Additional recommended comprehensive performance measures for the Interstate Asset Management Framework. Category Asset Type Measure Type Measure Shoulders Asset Performance Percent functioning as intended Tunnels Asset Performance Percent functioning as intended Culverts/drainage structures Asset Performance Percent functioning as intended Noise barrier walls Asset Performance Percent functioning as intended Retaining walls Asset Performance Percent functioning as intended Overhead sign structures Asset Performance Percent functioning as intended High mast light poles Asset Performance Percent functioning as intended Lighting Asset Performance Percent functioning as intended Median barriers Asset Performance Percent functioning as intended Impact attenuators Asset Performance Percent functioning as intended Surveillance and monitoring equipment Asset Performance Percent functioning as intended Signal and control equipment Asset Performance Percent functioning as intended Rest areas Asset Performance Percent functioning as intended Toll plazas Asset Performance Percent functioning as intended Weigh stations Asset Performance Percent functioning as intended Maintenance depots Asset Performance Percent functioning as intended Pump houses Asset Performance Percent functioning as intended Preservation Communication facilities Asset Performance Percent functioning as intended Mobility Winter Maintenance Average time to restore pavement surface Schedule Adherence Percentage of total projects finished on or before original scheduled contract completion date Delivery Cost Control Annual ratio of actual construction cost to bid amount

• Average IRI is recommended as a measure of ride quality. This recommendation is based on the fact that IRI is avail- able through HPMS data and is the most common measure available for characterizing ride quality. However, there are significant state-to-state differences in measuring IRI and issues with the measure that complicate use of IRI as a standard. • There is a need for definitions of a new, standard measures of bridge condition and functional adequacy. The existing measures defined by FHWA include SD/FO classification and Sufficiency Rating (SR). Of these, SD classification best measures condition, but is a binary measure (a bridge is or is not SD). Ideally, a numeric index would be defined that allows for specifying different levels of urgency for addressing bridge needs. Also, ideally this measure would be based on more objective measures of bridge condition than possible using the current set of bridge condition ratings. FO classification measures functional adequacy, but is also a binary measure, and a number of agencies do not report this measure when discussing bridge conditions either because they feel it misstates the level of need and/or needs to be updated to better reflect current functional standards. SR is problematic as it combines structural and functional consid- erations, complicating interpretation of the measure. Various efforts have been undertaken to define alterna- tive bridge measures, but these have thus far failed to result in widespread adoption of new, standardized measures. Most notably, as described in Chapter 4, most agencies now collect element-level condition data, and can use this data to calculate the Health Index developed by California DOT. The basic conundrum in recent efforts to develop new bridge measures is that without improvements in data col- lection it is difficult to formulate measures that offer any real improvement upon the existing measures, and changes in data collection needed to yield new measures require wide- spread consensus if they are to be standardized between states. National leadership is needed to break this logjam. • There is a need for standard measures of condition for other assets beside pavement and bridges. Research is ongoing to develop level of service standards for asset management as part of NCHRP Project 20-74(A). In the absence of any standard measures for preservation of other assets, percent functioning as intended is recommended here. The major shortcoming of this measure is that lacking national stan- dards, each IHS owner must define what it means for a given asset to be classified as functioning as intended. If this mea- sure is to be used, further work is needed to define what it means for different asset types. • New measures are needed for characterizing environmental performance. There are few environmental measures that can be both localized to the IHS and used to support the asset management process. Also, there is little consistency from one IHS owner to another concerning how envi- ronmental data are collected and reported. For instance, measures of emissions are often used for characterizing environmental impact (e.g., pounds of carbon monoxide and/or other pollutants) and these measures can be calcu- lated using systems such as HERS. However, it is not mean- ingful to report the measures specifically for the IHS in the absence of corresponding data for other systems. Other measures of environmental performance include counts of environmental features that are constructed or maintained (e.g., wildlife crossings, culverts/fish passages and other features), measures of wetland reclamation (e.g., the ratio of wetlands reclaimed to that affected), and measures of how well an agency is meeting its environmental commitments. These measures are meaningful when localized to the IHS, but there is no standardization in how they are reported between agencies. • There are no standards for characterizing project delivery. AASHTO’s report on comparative performance measures between state DOTs (26) discusses this gap and identifies the need for one or more standardized delivery measures to facilitate comparative measurements. 43

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TRB’s National Cooperative Highway Research Program (NCHRP) Report 632: An Asset-Management Framework for the Interstate Highway System explores a framework for applying asset-management principles and practices to managing Interstate Highway System investments.

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