National Academies Press: OpenBook

Measuring Transportation Network Performance (2010)

Chapter: Chapter 2 - Understanding Network Performance Measurement

« Previous: Chapter 1 - Introduction
Page 2
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 2
Page 3
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 3
Page 4
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 4
Page 5
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 5
Page 6
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 6
Page 7
Suggested Citation:"Chapter 2 - Understanding Network Performance Measurement." National Academies of Sciences, Engineering, and Medicine. 2010. Measuring Transportation Network Performance. Washington, DC: The National Academies Press. doi: 10.17226/14425.
×
Page 7

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

2Traditionally, transportation planning and project devel- opment practice has focused on the impacts of discrete types of investment strategies in relation to specific transportation goals, with goals most often tied to a modal or even functional aspect of the transportation system, funding source, or par- ticular transportation function. This silo-based approach to planning and project development has carried over into per- formance measurement, with measures that assess individual investment options and do not provide a true systems-level perspective. Federal funding programs, organizational barriers, and other factors mean that performance management tech- niques are often applied within silos. Furthermore, although several transportation organizations have begun to develop more comprehensive performance measures that better reflect their diverse planning goals and objectives, measuring per- formance for the transportation network and using measures across various stages of the transportation planning process remains a challenging endeavor. Several recent trends in systems planning and performance measurement have begun to increase the amount of attention paid to network- or systems-level performance measurement. Though the list is not comprehensive, some of the most impor- tant examples include • Congestion management. The growth of the congestion management process (CMP) has resulted in agencies con- sidering a broader range of strategies to tackle congestion, including, in particular, multimodal investments. • Linking planning and operations. Increased attention has been paid to bringing operations into the mainstream planning and project development process. Though plan- ning and operations have traditionally been addressed sep- arately, there is increased realization that data collected for operations purposes also can support the planning process and that the planning process must address operational needs and evaluate operational solutions (e.g., incident management and intelligent transportation systems [ITS]) alongside traditional capacity solutions). This integration is considered both as part of the CMP and as part of state met- ropolitan planning more broadly. The FHWA has authored guidebooks to address linking planning and operations at both state and metropolitan levels. • Corridor coalitions. Growth of corridor coalitions has spurred an increase in addressing transportation system needs across long-distance corridors using a wide range of strategies (e.g., capacity additions and operational improve- ments) and modes (e.g., highway, rail, and transit). These coalitions are increasing the recognition of freight move- ments and their impact on the system, especially over long- distance corridors. These efforts have attempted to address the multiple impacts of transportation projects (i.e., transportation, economic, environmental, and community) and an under- standing that traditional new-capacity projects are no longer feasible in many areas and have to be fully justified when they are considered. Network Performance Measurement Framework Components of Network Performance Define the Network From the traveling public’s perspective, transportation sys- tems are not bounded by the jurisdictional boundaries or functional mandates that tend to drive current planning and C H A P T E R 2 Understanding Network Performance Measurement System performance depends critically on how the parts fit and work together, not merely on how well each performs independently; it depends on interactions rather than on actions. Furthermore, a system’s performance depends on how it relates to its environment—the larger system of which it is a part—and to other sys- tems in that environment (Ackoff, 1980, p. 7).

3project development processes. These transportation system boundaries are a result of transportation planning and fund- ing mechanisms needed to develop, operate, and maintain transportation infrastructure within the context of a larger regulatory and political framework. As such, a way is needed to communicate performance of transportation investments that makes sense to the system user. Network performance measures are intended to span these boundaries in order to produce a more meaningful picture of transportation per- formance and, as a result, communicate to transportation stakeholders why particular investment strategies are chosen for funding and how well they are meeting expectations. Transportation agencies already are beginning to work together across jurisdictions and scales of government (e.g., state, regional, and local) to improve performance measure- ment. Because differences exist between various agencies’ organizational and functional mandates, it can be challeng- ing to develop a common set of multijurisdictional perfor- mance measures to assess the impact of the system in relation to mutual goals and transportation objectives. With multi- ple jurisdictions working together, the number of potential actors compounds issues (e.g., what performance data is to be collected, which data matters, and how data can be used to inform decision making). Yet collaboration of multiple actors can ultimately yield more meaningful and compre- hensive measurements. Use of performance information can be increased and improved through collaboration and dialogue between jurisdictions and across scales of govern- ment (interagency) or between individual units within an agency (intra-agency). Agencies also are increasingly setting goals to improve multimodal mobility and accessibility. Agency performance measures already are commonly used to assess various indi- vidual modes, but most often in isolation of one another. There are challenges to measuring multiple modes across a network, or the connectivity of modes within or between sys- tems, with the most common being technical issues associ- ated with predicting multimodal effects of projects and plans using tools limited by network scope and detail. As interagency and intra-agency partnerships increase and tools improve, agencies can develop and use multimodal measures to assess a broader array of investment strategies, improve decision- making processes, and determine if the transportation net- work as a whole is improving mobility and accessibility for all system users. A related issue is that the measures are typ- ically associated with investment options that fall within a particular silo. For example, many agencies report some mea- sure of overall congestion. However, they typically do so only in the context of roadway investments, rather than including multimodal investments. Similarly, many agencies are setting goals to provide needed transportation capacity through more cost-effective projects, rather than traditional roadway widenings. Systems operations projects, in particular, are a growing component of planned investments. These types of investments function differently by providing additional capacity through more efficient traffic operations and smoother traffic flow, without requiring new roadway infrastructure. They are multistrategy in that there are multiple approaches to achieve an agency’s goals. Similar to challenges associated with multimodal measures, compar- ing the benefits of smaller-scale investments, such as system operations projects, to larger roadway projects is hindered by limitations of commonly used technical tools, which have been developed over decades to assess the impacts of added roadway capacity. The same can be said for other types of smaller-scale investment strategies intended to improve traf- fic flow and transportation efficiencies (e.g., travel demand management measures). In addition to the jurisdictional, functional, and modal factors highlighted above, network performance measures also can be applied to span the various stages of the plan- ning process, including project identification, evaluation, selection/programming, and development (environmental review and construction). Often, these stages of the plan- ning process are managed by different agencies or groups within particular agencies, and the methods for perfor- mance evaluation at various stages can be very different. For example, a newly identified project may be evaluated in terms of a congestion reduction metric, programmed for funding based on a cost-benefit metric that may include other benefits, and administered through the project devel- opment processes based on a project deliverability/readiness metric. This multistage aspect is a critical dimension of net- work performance measurement, because it links planning to implementation. Framework for Implementing Network Performance This handbook provides a framework and a set of scenar- ios to help transportation agencies define approaches and specific performance measures to address network perfor- mance. Figure 2.1 presents the basic framework, building on the dimensions identified above. The left half of the diagram indicates the dimensions and the right half describes the basic process for considering network performance. The remainder of this section describes this process for addressing network performance. Define the Network It is important to define the network part of network per- formance early in the process. Put simply, the network is the combination of (1) the relevant agencies or jurisdictions— state, regional, and local—that have existing or proposed infrastructure within the geographic area under consideration

and (2) the relevant transportation modes. As an agency or set of agencies begins to address a congestion problem (or a safety, renewal, or environmental problem), considering the full set of relevant agencies and modes to include in the net- work will improve their understanding of the specific prob- lem and the potential range of solutions. Defining the network will depend, in part, on the scale of the problem under consideration. For example, a focus on commuting challenges to a specific destination might con- sider all modes and all types of travel, while a focus on inter- city congestion issues might not examine local transit but def- initely include intercity rail. Define the Partnership—Organizing Principle of the Handbook Along with defining the network, it is important to define the partnership. Who is involved and has a voice or control over decisions? Though several important dimensions of network performance have been defined, the partnership 4 Figure 2.1. Network performance measurement framework concept. Multistrategy Multiple Modes Network Performance Analysis Process Multiple Jurisdictions Multistage Define the Network Define the Partnership Identify Relevant Strategies Identify Relevant Measures Use Measures to Evaluate Strategies Network Performance Dimensions

dimension is used to organize this handbook. Partnerships refer to the forum used by a set of agencies measuring net- work performance (as well as tackling other issues). Partner- ships are primary because nothing else can happen without them. Until a set of agencies agrees on an approach and a forum to make decisions, network performance measure- ment cannot take place. The specific partnership arrange- ment will respond to the conditions and questions that the individual agencies have. Three basic types are relevant: 1. Single region. The most common existing partnership model for considering network performance is the metro- politan planning organization (MPO) or other regional agency. MPOs provide a deliberative forum for making regional decisions. These bodies can consider the entire transportation network and tradeoffs among modes and strategies. In some states, there is a similar collaborative approach, at least across modes, but MPOs are more common. The MPO is federally defined with require- ments for inclusion. 2. Peer-to-peer. With the growth of metropolitan areas and the increased recognition of multiregional and multistate issues, such as long-distance freight movements, a new form of partnership is emerging to address these issues. These partnerships are between agencies (two or more MPOs, or two or more states) that are peers. Network per- formance measures can be useful for supporting two dif- ferent types of peer-to-peer partnerships: – State-to-state partnerships are increasingly common through various corridor coalitions that have been established for individual projects (e.g., the I-10 Corri- dor Coalition) or on an ongoing basis (e.g., the I-95 Cor- ridor Coalition). In addition, sets of states often develop multistate compacts to address individual transporta- tion challenges. – MPO-to-MPO partnerships for performance measure- ment are less common, but the growth of metropolitan areas has increased the need to address transportation issues across MPO boundaries. In several states, indi- vidual MPOs are defined by county boundaries, and the true area of commuting spans these boundaries. In addi- tion, megaregions are increasingly spanning multiple multicounty MPOs. 3. Intra-agency partnerships. Because partnerships are the organizing principle of this handbook, individual agency attempts to consider the network-level implica- tions of transportation decisions have not been the focus. However, even within a given agency, there are often different groups with responsibilities for different pieces of the system or different types of investment. For exam- ple, a state may want to evaluate tradeoffs across capac- ity expansion and operations investments to address congestion. The measures and considerations identified in this handbook may be useful for these circumstances as well. Define Network-Level Performance Measures What are network performance measures and how are they used to measure transportation network performance? Though no specific definition of transportation network per- formance measures exists, the measures encompass certain criteria and qualities. Network performance measures • Address the regional, state, or multistate impacts of indi- vidual decisions; • Are derived from a process that involves multiple actors working in collaboration; • May span multiple jurisdictions, modes, investment strategies, and stages of the plan and project development process; • Are connected with broader outcomes and systemwide performance objectives; • Measure the performance of a transportation network, not only individual facilities; and • Are supported by data and tools that provide a fair com- parison of different types of investment strategies. Define Network Performance Strategies One of the key dimensions of network performance is the consideration of multiple types of strategies. The significant cost of and lack of physical space for new transportation capacity (whether highway or transit) have increased the inter- est in system operations solutions. Like modal silos, perfor- mance measurement has often been conducted separately for different types of strategies. Again, defining the appropriate strategies will depend on the scale of the effort under consider- ation and the modes and jurisdictions involved in defining the network and partnership. Apply Network Performance Measures Applying the network performance measures will depend on context. Examples of application may include the following: • Corridor-level performance measures. Measure investment strategies across an entire corridor that spans jurisdictions 5

(e.g., congestion measures, crash reduction, and environ- mental impact); • System-level performance measures. Measure the cumu- lative effect of investment strategies at the systems level (e.g., air quality measures for conformity analysis); • A project selection process that compares benefits and impact across multiple modes and investment strategies; and • Project development activities that ensure investment pri- orities are established using one set of metrics throughout the project development process. Introduction to the Scenarios Table 2.1 describes the five scenarios that can help an agency or group of agencies apply network-level performance measures. The scenarios reflect one or more case studies conducted for this project. For most of the scenarios, a primary case study is identified in the table, but information from other case studies is also presented. The complete set of case studies conducted for the project is available in Appendix B. Select literature that was the foundation of this effort is discussed in Appendix A. 6 Table 2.1. Handbook scenarios. Chapter Scenario Name Scenario Description Primary Case Studies 3 Regional Scenario – Defining Community Goals Across Jurisdictions State and regional policy, program, project, and operational decisions can have significant implications for local communities. Conversely, local transportation projects and operational strategies can have impacts that are felt far beyond the borders of the municipal boundaries. Statewide and regional entities are working collaboratively with local governments and transportation providers to assess the impacts of these decisions on a systems level and fully understand and plan for the implications. Capital District Transportation Commission planning process 4 Regional Scenario – Multimodal and Multistrategy Investment Prioritization Decreasing resources and an interest in funding projects with the most favorable benefit–cost ratio has increased the interest in analyzing all projects across a system for planning and programming purposes. These efforts typically include many entities with varying responsibilities for the transportation network. Bay Area Metropolitan Planning Commission Transportation 2035 Plan: Change in Motion 5 Peer-to-Peer Scenario – Multistate Partnership for System Operations Many key corridors throughout the country cross state boundaries, creating a complex web of players who are responsible for the planning and operations of what for users is a single transportation network. Infrastructure improvements that directly address a problem for one mode may have important impacts (both negative and positive) for other modes. Without the data to analyze these improvements across state lines and among agencies, and without the forum to vet and discuss the implications, the most effective investment decisions may be lost. Mid-Atlantic Rail Operations Study, I-95 Vehicle Probe Study 6 Peer-to-Peer Scenario – Megaregional Partnership to Address Growth As metropolitan regions expand, they become increasingly linked via economic interdependence and common transportation corridors and networks. These new “megaregions” share common issues, including economic growth, environmental concerns, and mobility. As the regions expand, there is an increased need for planning and operations considerations among existing jurisdictions and agencies, including both those that cross state boundaries and those that fall within one state. San Joaquin Valley Partnership Regional Blueprint 7 Intra-agency Scenario – Linking Planning and Operations at a State DOT Several agencies have addressed network performance within the context of a single agency. State DOTs are increasingly recognizing the need to link their planning and operations investments both to better address issues such as reliability and to share investments in data collection and tool development. Oregon Transportation Plan update, Washington State Gray Notebook

The scenario chapters are organized in the same way to aid in connecting the information presented in this section to the specific scenario. The organization is as follows: • Scenario. A short description of the basic motivation for and components of the scenario. • Case Studies. A summary of the primary case study used to illustrate the scenario and identification of additional case studies. • Building blocks. The scenarios describe specific applica- tions of network performance, but a common set of build- ing blocks also has been identified. These building blocks include the following: – Establish Partnership Agreements. This building block addresses the first step in the network performance process: setting up a partnership among agencies or dif- ferent departments within an agency. These partner- ships set the stage for using network performance to address a specific challenge. – Define Performance Measurement Framework. Early in the process, it is important to establish a common set of goals and objectives between agencies and identify modes and strategies to be considered. This building block addresses the steps in the network performance measurement process to define the network and iden- tify strategies. – Develop Measurement and Data Collection Method- ologies. Network performance analysis requires data and analysis tools to be able to capture strategies that cross jurisdictions or can apply to multiple modes. In some cases, data may already exist and need to be inte- grated, but in others new data may need to be col- lected. Performance measures also need to be defined. This building block addresses two steps of the net- work performance process: developing performance measures and using measures to address network performance. 7

Next: Chapter 3 - Regional Scenario Defining Community Goals Across Jurisdictions »
Measuring Transportation Network Performance Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

TRB’s National Cooperative Highway Research Program (NCHRP) Report 664: Measuring Transportation Network Performance explores ways to monitor transportation network performance by developing new or integrating existing performance measures from different transportation modes and multiple jurisdictions.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!