Relationship to Federal TPM Activities

The MAP-21 Act (2012) established a performance-based program intended to focus Federal Aid highway program and public transportation system (e.g., bus, light rail, and ferry) investments on national transportation goals. It was also intended to increase accountability and transparency in the use of federal transportation funds, as well as improve project decision-making through the strategic use of system performance information. The performance-based provisions of MAP-21 were retained in the FAST Act in 2015.

TPM is defined by FHWA as a strategic approach to making investment and policy decisions to achieve national performance goals using system information in accordance with rules established by the Department of Transportation (see Figure 2.3). The FHWA recognizes asset management as the application of TPM to manage the condition of infrastructure assets needed to provide for mobility and safety in the nation’s transportation system. In short, the FHWA refers to asset management as the engine driving infrastructure performance.

Asset management plans document the processes and investment strategies developed by an agency to manage its infrastructure assets. These asset management plans support an agency’s performance-based planning and programming processes for making long-term investment decisions and feed shorter-term project and treatment selection activities. Together, these activities ensure the investment decisions of an agency are aligned with performance objectives and goals.

TPM Regulations

The TPM provisions for highways included in federal law are implemented in accordance with rulemakings organized around the following six elements:

• National goals – focusing the Federal Aid highway program on the seven areas listed below:
• Congestion reduction
• System reliability
• Environmental sustainability
• Freight and economic vitality
• Infrastructure condition
• Reduced project delivery delays
• Safety
• Measures – assessing performance or condition in carrying out the TPM-based Federal Aid highway program
• Targets – funding recipients are required to document future performance expectations under a fiscally-constrained environment
• Plans – identifying strategies and investments for addressing performance needs
• Reports – documenting progress toward target achievement and investment effectiveness
• Accountability and transparency – requiring federal funding recipients to achieve or make significant progress toward targets

TPM Relationship with TAM

There is a close relationship between TPM and TAM, since both consider asset and system performance, risks and available resources to achieve desired objectives over time. Both rely on a strategic approach, using data to make investment and policy decisions in order to achieve performance objectives. Internationally, there is less distinction between asset management and performance management, with the IAM defining asset management as encompassing the “balancing of cost, opportunities and risks against the desired performance of assets to achieve the organizational objectives.” In the United States, TAM applies to the technical and financial decisions, plans and actions related to physical infrastructure, while TPM considers a broad range of system performance categories.

A graphic illustrating the integration of asset management and performance management is provided in Figure 2-4. In the figure, the circle on the left represents the interconnection of the various performance areas that transportation agencies are concerned with throughout their planning processes. Flowing into the performance circle is the asset management circle, representing an agency’s infrastructure needs to support system performance.

The FHWA’s Expert Task Group (ETG) published a white paper explaining the relationship between asset management and performance management. It acknowledges the performance of a transportation system is dependent on many factors, including operational characteristics, and system usage and demand, in addition to the physical condition of the infrastructure assets. The paper explains that “performance management focuses on how policies, resource allocation, and other decisions affect all aspects of system performance including safety, operations, environmental stewardship, and infrastructure condition.” (FHWA 2019) Asset management is described as an application of performance management principles with a long-term focus to manage the performance of infrastructure assets, the resources allocated to operate a transportation system, and the investments made to achieve the agency’s long-term goals and objectives.

Performance Management Framework

To support the alignment of agency policies, objectives and day-to-day practices, agencies may establish a tiered performance management framework, such as the example illustrated below for a model Design-Build-Finance-Maintain-Operate (DBFMO) project (Figure 2.5). The highest of the three levels, Key Performance Measures, defines the high-level outcomes for service delivery in terms of a few key strategic areas. The second level, Asset Preservation Performance Measures, defines the minimum acceptable condition levels for each of the individual assets to preserve their value. The third level, Operational Performance Measures, corresponds to the many specific requirements for operating and maintaining the highway in a safe manner on a day-to-day basis.

Further discussion on Performance Management Frameworks, defining Performance Measures and Performance Targets is included in Chapter 6.

For the transit community, TCRP Research Report 198 presents a framework for developing relationships between service quality and asset conditions, using a variety of transit system performance and customer satisfaction attributes. The research conducted in developing the report found many correlations between asset condition and performance, as noted below (Spy Pond Partners, et.al, 2018).

• Asset condition is related to the quality attributes of Frequency, Reliability, and Travel Speeds. As assets decline in condition, failures become more likely, reducing frequency, reliability, and average speeds.
• Asset condition is related to Appearance/Aesthetics in that customer perceptions of this factor are likely to be worse when assets are in poor condition and/or are technically obsolescent.
• Asset condition is related to other service quality attributes, including Comfort, Ease of Access, Environmental Impact, Information, Safety, and Security. For these attributes, increasing asset failures may affect quality, although the effects may be difficult to model. For instance, reduced service frequency resulting from increased failures can lead to greater crowding and less comfort. A particularly challenging area is safety. Given that operating severely deteriorated assets could compromise safety, in theory and in general practice, transit agencies establish thresholds for safe operations and remove an asset from service, rather than operating unsafely. Thus, potential safety issues tend to become operational issues, rather than actual safety issues. Regardless, customer perceptions are likely to be worse when assets are in poor condition for these factors, as in the case of Appearance/Aesthetics.

In one example, the impact of State of Good Repair (SGR) investment on the calculation of Effective Journey Time (EJT) is demonstrated. The example illustrates the differences in the calculated unadjusted and adjusted journey time, both before and after SGR investment, for a hypothetical rail line. Although the calculation is not based on actual data, it is intended to show that, after a SGR investment, both the adjusted and unadjusted journey times decrease. Before investment, the actual journey time for all components is 19.1 minutes, increasing to 23.4 minutes when adjustment factors are included. Following an investment in improved vehicles and track, these journey times decrease to 13.3 and 16.6 minutes. Looking closer at the components of time that change in this example, the decrease in buffer time after SGR investment indicates that travel times are more reliable and passengers do not have to build in as much buffer when planning their trips. Overall, in this example, SGR investments reduce EJT an average of 6.8 minutes per trip. This savings can be multiplied by an average value of time and number of trips per year to yield a prediction of the annual user benefit resulting from the investment. The results can be used in a variety of ways to analyze asset conditions and service quality.

TAM is an evolving process; ongoing improvement is an important component for a TAM program. In fact, the ISO 55001 Asset Management certification requires ongoing assessment and continual improvement.

A gap assessment process is used to understand how well an agency aligns with an established asset management framework. The gap assessment can be conducted internally or by a third party. Organizations seeking or wanting to maintain ISO certification will also undergo a formal third party audit.

The results of a gap assessment can help agencies identify changes in business processes needed to better link plans and decisions and better align to leading practice.

NCHRP Project 08-90 led to the development of a gap analysis tool, available through AASHTO and the TAM Portal. Figure 2.8 illustrates how this assessment tool is intended to be used. There are several other frameworks that can be used, including ISO 55001 and the Institute of Asset Management (IAM). A range of gap assessment framework’s are discussed further in Table 2.1. Each framework, process or tool will enable an agency to assess current performance and, from this, identify a desired capability level.

Figure 2.8 TAM Improvement Cycle

Source: Modified from original in NCHRP Project 08-90

In some cases, agencies also seek benchmarks that reflect how peers are performing to help them decide on the level of maturity and complexity to which they should aspire. ISO 55001 trends away from this. It encourages agencies to check against a framework of practices and process, and select what is best for the agency. Chapter 6 addresses benchmarking and related topics.

Actions to close gaps between desired and actual performance should be addressed within a TAM improvement or implementation plan.

Undertaking a gap assessment can form an important part of a change management process by aligning those within the agency on current performance, opportunities and targets for improvement.

For transportation agencies, asset management typically begins with the high-visibility, high-value assets, such as pavements and bridges. However, operating the transportation system requires a supporting cast of assets, typically referred to as ancillary assets, that include lighting structures, roadway signs, ITS assets or even operations facilities and technology hardware components. Establishing the appropriate management approach, and future desired approach for each asset is an essential step in strategic planning for asset management, defining boundaries around the effort. Furthermore, for each type of asset, it is important to determine how broadly to define the inventory of assets, such as the decision to include only arterial roads initially or all roads in a network.

Defining Appropriate Management Approaches for Different Asset Categories

An appropriate approach to manage and monitor each asset governed by the TAM framework needs to be established. Depending on the nature of the asset and the level of risk involved, different approaches can be selected by an agency.

Structuring asset management also involves evaluating different management approach- es and defining the appropriate level of maturity. There are several approaches to managing highway assets, each with different data needs, and several ways to structure and implement asset management processes. These include:

• Reactive-Based. Treatment is performed to fix a problem after it has occurred.
• Interval-Based. The asset is treated based on a time or usage basis whether it needs it or not.
• Condition-Based (Life Cycle Approach). Select intervention based on a forecasted condition exceedance interval.

Chapter 4 provides more details on these different approaches to managing assets.

Processes and approaches can range in their level of detail and complexity. This is what forms the foundation of some asset management maturity levels. Much like deciding on the scope of assets to manage, the level of advancement of the asset management processes an agency adopts should depend on the context and readiness of the agency, as well as the problem being addressed. Consideration should be given to the data, processes and tools available to support the asset management approaches and processes, as well as resource availability and capability. It is common for an agency to begin at a simple level and mature over time towards more complex asset management that integrates processes and decision-making.

Prioritizing TAM Improvements

Deciding on the appropriate management approach and level of asset management is a strategic decision that should consider several factors:

Organizational Strategic Goals

The decision of which assets to prioritize should be driven by the organization’s strategic goals. A desire to focus on one aspect of the transportation system over another in order to meet a larger objective can present a good reason for prioritizing some assets over others.

Asset Value

A common consideration for selecting assets to include is the financial value. Monetizing value provides a consistent way of comparing asset classes. In general, assets that are the most expensive to replace or cause the greatest financial concern for an organization fall into the highest priority. Strategic management of these assets means strategic investments over the life cycle of the asset, which will prevent or delay the need for significant additional investment, help avoid premature failure, and allow time to plan for appropriate replacement.

Data Availability

TAM as a concept is heavily dependent on data. Deciding on which assets to focus on based on existing data collection and management practices and will often support achievement of “quick wins.” Data availability does not always indicate strategic priority or risk exposure of the asset, but can still be an important factor in selecting assets to include the cost of collecting and analyzing data to form the basis for more advanced TAM decision making can in some instances be significant, and require new skills and training.

It should be recognized that data does not need to be comprehensive and complete as a basis for TAM decision making. An accepted approach is to group assets into classes (age, type, function) and then inspect a sample set. This can provide important insights to guide long-term planning at minimal initial expense/time. It can also highlight any issues with particular types of assets and allow for more detailed inspections to be undertaken if required. A gap analysis to define future data requirements and determine how to collect this data should be considered for long term TAM outcomes.

Risk of Failure

Often, it can be necessary to consider including assets if the probability and consequence of failure is significant. Assets with a high risk of failure can be a high priority due to the potential losses to the agency and its stakeholders should they fail. Asset management can alleviate or prevent the impact of failure.

Asset Criticality and Network Reliability

Decisions to formally manage certain assets can be based on their importance to the service provided, such as operations, or the importance of the travel paths under consideration. Defining criticality is context specific, but is important, since user experience is based on the journey, not the specific assets. Considering criticality in selecting assets to include in TAM will ensure that the most important assets–those necessary to maintain network reliability–are managed first.

Stakeholder Influence

In general, the scope of TAM should be agreed to in coordination with leadership and influenced by stakeholders. Stakeholders can be any asset owners, metropolitan planning organizations (MPOs), cities, tolling authorities, P3 concessions, federal (mandated requirements), and others. The public can also be stakeholders who influence which assets to include, especially when high-profile incidents potentially attributed to the state of good repair occur.

The product of a gap assessment will often take the form of an implementation plan for TAM improvements. These improvements can involve changing behaviors across many business units within an organization. The actions should, therefore, be prioritized and staged to advance one step at a time. When defining actions, it is important to understand the purpose and outcome to be achieved, who is responsible, how long it will take and how many resources are required for it to happen.

Note that a TAM Implementation Plan is different from a Transportation Asset Management Plan (TAMP) described further in Section 2.4. An implementation plan focuses on business process improvement, while a TAMP focuses on an organization’s assets and how it is investing in and managing them. However, the implementation plan may be included as a section of a larger TAMP.

The improvements identified need to recognize potential barriers to implementation. As an example, improving decision-making tools will likely require improvements in data practices. The implementation plan should consider any foreseeable obstacles, including staff resistance to new business procedures, lack of support from agency leadership, inadequate skills among staff, data integration issues or outdated analytical tools.

Communicating the Implementation Plan

Effective, organization-wide communication can serve as a powerful tool to facilitate smooth and swift adoption of the TAM implementation plan. At the start of implementation, communicating the future vision and benefits can help build awareness and buy-in. Throughout the duration of the implementation initiative, communication about milestones and accomplishments can help sustain or regain momentum. Additionally, as different projects are initiated, delivered and completed, agencies will want to ensure that the resulting changes in processes, systems and tools are adopted and used consistently to achieve the intended outcomes and objectives. As illustrated in Figure 2.9, the TAM communication strategy should cover six key elements – why, who, what, when, how and how well.

Objectives. Why communicate?

Establishing early buy-in to the implementation plan by providing an upfront explanation of why execution of the TAM implementation plan is needed—the anticipated benefits for the organization as well as for different stakeholder groups—will help jumpstart success of the implementation.

Stakeholders. Who delivers and receives the communication?

To make sure the right people are receiving the right information, it is key to develop and categorize a complete list of internal and external stakeholders who will be impacted by the TAM implementation plan and its resulting changes. In determining stakeholders, consider who needs to receive different types of information and who best to deliver that information to support achievement of implementation plan objectives.

Messages. What are the messages to communicate?

In developing the key messages to communicate, consider intent – what should stakeholders know, think or do as a result of the message? Key messages should promote awareness, desire and reinforcement of the implementation plan and its associated changes. They should also align with objectives of the implementation plan as well as organizational objectives.

Timing & Frequency. When will the communication occur?

Communication about the TAM implementation plan and corresponding changes should be timely, frequent enough to keep stakeholder groups well informed about approaching milestones and key dates of impact, and not so frequent that they lose value. Take into account what is being communicated and to whom, as different stakeholder groups receiving different types of messages often require different delivery frequency.

Tactics & Channels. How will information be communicated?

Depending on the duration of the TAM implementation plan and the number of associated changes, communication needs often shift over the course of its execution. Agencies should determine the most effective types of communication and delivery channels as they progress through change. By including stakeholder categories, messages and frequency as inputs when determining the most effective channels, the communications strategy remains agile, which facilitates continuous improvement.

Continuous Improvement. How well is the communications strategy working?

Assessing the effectiveness or performance of any strategy is important for achieving objectives. Including a stakeholder feedback loop into the communications strategy is one way to accomplish this. Agencies can use surveys, polls, focus groups or meetings to gather information and gauge opposition and support. This crucial feedback serves as guidance for subsequent content and can lead to changes in the communications strategy.

Once a commitment to make improvements has been made, the improvement process needs to be managed and monitored.

Regular updates, meetings, performance tracking (monitoring improving performance against the selected framework) and scheduled reviews by the TAM Governance Groups will help provide oversight to those responsible for undertaking the improvements.

This process also helps remove roadblocks by involving leaders from across the organization.

When to Re-Assess Performance

A regular commitment to monitor progress is important. This assessment will compare progress from the initial benchmark toward the desired level of competency. There is no set recommendation for when to assess progress; some agencies find it more important in the early stages of implementation, while others do not.

When considering the timing of progress assessments, it is important to consider:

• Process checkpoints. The frequency could be aligned with reporting requirements, but should also consider appropriate points where progress will be noticeable.
• Commitment. Undertaking an assessment will take time and resources, so it is important this is balanced against progressing with implementation.
• Champions and change agents. As these individuals are critical to the overall success of TAM implementation, if they change or need to monitor their own performance, then a review of progress can help motivate and reset goals.

Measuring Performance Improvements

Monitoring performance of the asset management system and the results of improvement actions can be challenging, as the cost of service delivery, quality of service levels and risk of service failures may shift over time, and can change following the implementation of an improvement action. The IIMM suggests some of the following potential TAM system performance indicators:

• Financial performance
• Data management performance
• Timeliness relative to target response times
• Productivity and utilization of resources
• Skills availability relative to planned requirements
• Adherence to quality procedures

Chapter 6 provides more information on performance measures, targets, and monitoring asset performance. Self assessment can focus both on service / asset outcomes experienced by users, as well as be internally focused to determine how well the agency is aligned with desired practices. It is important that agencies consider and select the appropriate level and focus of self-assessment for their requirements.

Establishing Desired Levels of Service

Before a whole-life strategy can be developed and implemented, an agency must determine what they seek to achieve. In many transportation agencies, the desired level of service (or asset management organizational objectives, in ISO 55000 terminology) provides the linkage between what the goals of an agency are, and what investments and interventions should take priority when managing assets. High level goals should directly influence investment choices when resource allocation decisions are made. Service levels help establish when gaps need closing to achieve a goal, and merits investment. Chapter 2 discusses ways to create linkages between goals and investment decision making.

When managing the life cycle of existing assets, performance targets are commonly established as a way to manage service levels for the transportation network. How to determine the expected level of performance may vary depending on the type of asset being managed. Level of service targets that are part of performance framework typically are a mixture of both customer focused performance measures, and technical service measures that help those responsible for the asset assess what types of interventions might be required and when. Customer focused service measures are important to road users and other stakeholders that require mobility. Travel time reliability, safety, load capacity and clearances, and lane availability are all examples of service targets that are customer focused. Condition, strength, regulatory compliance and examples of technical service attributes are commonly of greater interest to asset stewards than asset users. Both types are service level targets that are important to evaluate the efficacy, effectiveness and efficiency of a transportation system.

For pavements and bridges, and other assets managed using a condition-based approach, asset condition is commonly used to establish expected technical levels of performance, but also is relevant to customers. For example, condition is employed as a proxy in this way for pavements because it is objectively measurable, deterioration has some predictability. It is a valuable service attribute because often, user experience is also directly connected to condition as well. Potholes, rutting and roughness all reduce quality of service from a pavement. Performance measures, such as those discussed in Chapter 6, are used to establish the desired long-term performance and to set short-term targets that can be used to track progress towards the long-term objectives. For other highway assets, including those managed using interval- or time-based maintenance approaches, performance may be linked to the expected service life, the ability of the asset to fulfill its intended function, and/or other operational factors. For these other highway assets, performance targets are often established as part of a Maintenance Quality Assurance (MQA) program in terms of desired maintenance levels of service (MLOS) and integrated with operational service targets that may also be customer focused.

Risk can also be used as a measure of performance. As described in chapter 2, risk considers both the potential impact and consequence of failure. This can be particularly useful when the potential consequences of failure impact other assets or facilities. An example of how Colorado uses risk to manage rockfalls is included in section 4.3 of this chapter. Additional details on how to track risk-based performance measures is included in Chapter 6.

Establishing a desired level of performance is typically a collaborative process that considers existing conditions, available funding, expected demands on the system, policy goals and guidance, and stakeholder priorities. The desired level of performance is typically established once baseline data is available, so performance trends can be evaluated. The desired level of performance may be adjusted over time to reflect changes in agency performance, changes in asset condition, capacity, safety, resiliency and other factors.

Three types of service expectations are often used in combination to manage asset performance:

• Performance target – the level of performance beyond which additional performance gains are not desired or worth the additional cost. When performance is measured based on condition, the desired performance may describe the desired state of good repair. There may be an expected specific time frame to achieve this desires performance target.
• Current Performance – an intermediate level of performance achieved by the organization and is usually reported relative to the desired target. Target setting is described in more detail in Chapter 5.
• Minimum acceptable performance – the lowest level of performance allowed for the asset or asset class to still function as designed.

Performance expectations may be set for the road network, a road corridor, for individual assets or for a group of assets. Commonly, performance expectations are set using a combination of asset class or subclass or sub network, such as:

• Key network corridors.
• Bridges on the National Highway System.
• Interstate pavements.
• Culverts larger than 10 feet in diameter.
• Traffic signals serving more than 10,000 vehicles per day.

The nature of performance expectations can be either strategic or tactical or operational. Strategic expectations support freight movement; for example, the long-term goal of providing unrestricted flow of legal loads is supported by a performance expectation of no load-posted or restricted bridges on interstate highways. This expectation cannot be accomplished without the tactical delivery of work to address factors contributing to the physical condition of bridges. Thus, an agency may include tactical expectations to perform maintenance and repair on structural members on a routine basis or as conditions warrant. These enhancements can be also integrated with renewal and other rehabilitation interventions to help improve both tactical performance metrics, as well as achieve higher level goals and objectives. Operational improvements such as more responsive snow clearance, and better signage are all integrated treatment options to achieve the strategic objective.

Life cycle management analysis, and the decisions it supports, require service levels, performance targets and other objectives to be able to determine the optimal choices for agencies to select during resource allocation. Over an asset life cycle, a range of interventions are possible, from reactive, routine and preventative maintenance, to large investment associated with renewal, replacement, or removal. Having targets helps select the right interventions and investment option while balancing risk, service and cost.

Connecting performance measures to higher level strategic goals also supports an agency’s ability to communicate how technical measures relate to system performance as experienced by highway users and other external stakeholders, thus tying asset management outcomes to system performance. Asset management measures are often very technical. Performance indicators like bridge ratings, pavement distress measurements, and risk ratings are not commonly understood by those outside transportation agencies. However, agencies can use these technical measures to support the performance indicators that are more commonly understood and prioritized by system users and external stakeholders. Communicating system performance and the status of the road network is discussed in Chapter 2, and is illustrated in several examples below. Customer service level targets are often established for this purpose, and give users an ability to understand the quality of service they should expect on the transportation system.

Performance Management Framework

As discussed in Chapter 2, transportation agencies have embraced the use of performance data to drive investment decisions. A performance-based management approach enables agencies to select and deliver the most effective set of projects for achieving strategic objectives, while also improving internal and external transparency and accountability.

A typical performance management framework includes:

• A clear idea of the agency’s strategic objectives.
• The use of performance measures to assess performance.
• Methods to evaluate and monitor performance results.
• The evaluation of factors with capacity to improve long-term performance.
• The allocation of funding to achieve agency objectives.
• Ongoing processes to monitor and report progress.

A fundamental component of the framework is the use of performance measures to evaluate system performance and the importance of establishing business processes to evaluate, monitor, and use the data to influence agency decisions. These are achieved by aligning decisions at all levels of the organization with the agency’s strategic objectives and ensuring that the right performance measures are being used to drive decisions. This alignment helps to ensure that resource allocation decisions and the day-to-day activities of agency personnel support the agency’s priorities and the interests of external stakeholders.

The existence of a regular, ongoing processes to monitor and report results is critical to identifying and implementing improvements to system performance or to further the effectiveness of the performance management process. The continual monitoring and update of a performance management framework is reflected in Figure 6.1, which illustrates inputs to performance targets and how ongoing monitoring and adjustments are fed back into the framework to adjust future targets. The surveys conducted regularly to support a pavement, bridge or maintenance management system are examples of the types of performance monitoring activities fundamental to an effective performance management organization.

Agencies with a performance management framework in place have benefited from:

• Maintaining a clear and unified focus for making agency decisions based on agency priorities, public input and available resources.
• Using available funding more effectively to preserve or improve system performance while lowering life cycle costs.
• Allocating available resources based on analysis of past performance and expected conditions to address areas most in need of attention.
• Having the data to confidently defend funding requests or explain the impact of reduced budgets.
• Building a transparent and accountable organization by communicating the basis for making resource decisions.
• Meeting legislative requirements.

Performance Measures

Performance measures are used within a performance management framework to allocate resources and provide feedback on the effectiveness of the activities in achieving overall objectives. Performance measures are indicators used for evaluating strategies and tracking progress. A performance measure can be an indication of asset condition, such as a pavement condition rating, or an indication of an operational characteristic, such as the annual number of fatalities on a facility.

The most effective performance measures drive decisions that are important to the success of the program. For example, maintenance departments may use performance measures that track actual expenditures to planned expenditures to ensure that available funding is directed towards the highest-priority items, as shown in the North Carolina DOT practice example.

It is also important that the measures drive the desired performance within an organization. For instance, a performance requirement that measures whether pavement or bridge designs are submitted on time might cause incomplete or incorrect submittals to meet a deadline, leading to an increase in construction modifications. A more effective measure might focus on a minimal number of design modifications during the construction phase of a project.

Effective performance measures should also primarily be outcome-based rather than output-based, meaning that they focus on the result or impact of an activity rather than the inputs that went into the activity. Outcome-based measures are generally preferred because they indicate the effect on the traveling public resulting from the actions taken, so they usually relate to user priorities such as the length of time for a road to be cleared after a snow event or the absence of litter and graffiti. They are developed based on a description of what an agency wants to achieve as a result of the actions undertaken. Outcome-based measures are commonly used for managing ancillary assets such as drainage assets and signs. For instance, the performance of drainage assets might be reported in terms of the percent of pipes/culverts greater than 50 percent filled or otherwise deficient and the performance of signs might be reported in terms of the percent of signs viewable at night.

Output-based measures, on the other hand, track the resources used to achieve the outcome, such as the number of hours of labor used or the number of light-bulbs changed in a month. While the data is important information for managing resources, it does not necessarily drive outcomes that would matter to the public. For instance, travelers on a highway are much more interested in knowing when the road will be cleared of snow than how much overtime went into the operation.

When possible, agencies should use performance measures that are leading measures rather than lagging measures to influence future decisions. A leading measure uses changes in performance to provide insights into potential changes that might influence a future decision one way or another. For example, knowledge that a ramp meter has exceeded the manufacturer’s suggested service life might drive a decision to replace that meter. Similarly, increases in equipment downtime might indicate risks due to an aging fleet are growing or that planned operational activities will not be performed as planned. A lagging measure, on the other hand, looks back on the results of past investment strategies after the decisions have been made. Because a lagging measure is recorded after the fact, there is a delay (lag) in the agency’s ability to adjust its practices and improve performance. Bridge and pavement condition measures are examples of lagging measures because the reported conditions reflect the impact of decisions made several years in the past. Lagging measures are commonly used to evaluate a program’s effectiveness or to verify that actual investments achieved projected results.

In transportation, an agency might have a lagging measure for tracking complaints responded to within a 48-hour window. The measure provides an indication of the public’s satisfaction with the road network and is easy to monitor and report. However, if an agency really wants to effect change, it might develop leading measures to track the percent of complaints not worked on within a two-hour window or the percent of complaints that can’t be resolved by the initial point of contact and must be passed to someone else. Focusing on these types of measures could drive agency decisions to ensure complaints are being worked on quickly and are being assigned to the right people. General characteristics of effective performance measures are presented in Table 6.1.