National Academies Press: OpenBook

Performance Specifications for Rapid Highway Renewal (2014)

Chapter: Chapter 2 - Research Methodology

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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
×
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
×
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
×
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Suggested Citation:"Chapter 2 - Research Methodology." National Academies of Sciences, Engineering, and Medicine. 2014. Performance Specifications for Rapid Highway Renewal. Washington, DC: The National Academies Press. doi: 10.17226/22560.
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12 C h a p t e r 2 Performance specifications emphasize desired outcomes and results, challenging owners and their industry partners to think in terms of user needs and to recognize that more than one solution may achieve the project objectives. Incorporating such concepts into a specification represents a distinct depar- ture from today’s build-to-print culture and demands a new approach to specification writing, contract administration, and construction execution. To help advance this new approach, the R07 research team developed guide specifications and associated implementation guidelines to support the application of performance speci- fications across a wide range of work and projects. In prepar- ing these documents, the team focused its research efforts on addressing the following fundamental questions: • What are performance specifications? • How are effective performance specifications developed and drafted? • Why use performance specifications? • What are the risks associated with using performance specifications? • When should performance specifications be used instead of method specifications? • Who is affected by the implementation of performance specifications and how are they affected? What are performance Specifications? Context drives how performance specifications are defined within the construction industry. For example, the U.S. Depart- ment of Defense (DoD) describes a performance specification as one that states requirements in terms of the required results and the criteria for verifying compliance, without specifically stating how the results are to be achieved. A performance specification describes the functional requirements for an item, its capa- bilities, the environment in which it must operate, and any interface, interoperability, or compatibility requirements. It does not present a preconceived solution to a requirement. (DoD 2009) In addition to addressing end-product performance, as contemplated by the DoD definition, requirements for a high- way construction project could conceivably extend to project- related performance in terms of work zone management, safety, and timely completion. Postconstruction and operational per- formance, as found in warranties and maintenance agreements, also could be included. The first task for the research team was therefore to con- duct a comprehensive literature review to establish what the term performance specifications encompasses when applied to the highway construction industry. Literature Review To provide focus to the literature review, the team first deter- mined which elements of a rapid renewal project would benefit from the development and implementation of performance specifications. Bearing in mind the objectives of rapid renewal (i.e., accelerated construction, minimal disruption, and long- life facilities), the team identified both physical products of con- struction (bridges, earthwork and geotechnical systems, and asphalt and concrete pavements) and project-level require- ments (work zone management, public relations, quality index- ing, and time incentives) as areas for possible application of performance specifications. To provide additional structure to the literature review, the team also established baseline definitions (presented in Appen- dix B) of specification types and contracting methods that would fall under the umbrella term performance specifications. As described in Chapter 1, performance specifications may be viewed in terms of a continuum. Categorizing specifications (e.g., as end-result specifications or PRS) helps identify the Research Methodology

13 advancement of performance specifications in a particular topic area. The literature review effort itself entailed collecting and reviewing reports, specifications, contract documents, and similar information to determine the status of performance specifying in each of the topic areas considered. The primary resources consulted included relevant FHWA, AASHTO, and NCHRP reports, as well as additional reports, contracts, and specifications from departments of transportation, industry, and international sources. Particular emphasis was placed on obtaining documents that addressed product performance measures, incentives, measurement and verification strategies, risk allocation techniques, legal and administrative issues, and other information relevant to the development and imple- mentation of performance specifications. Content Analysis The collected literature was classified according to specification type (e.g., end-result, PRS, warranty, and so on), topic area (e.g., pavement, bridge, work zone management, and so on), and project delivery approach (e.g., design-bid-build, design-build, design-build-operate-maintain). Then it was screened for per- ceived applicability to subsequent specification development efforts on the basis of containing or suggesting the following: • Progressive or creative performance parameters, measure- ment strategies, test methods (NDT or otherwise), or acceptance criteria appropriate to the rapid renewal environment; • Techniques to transfer performance responsibility from the owner to the contractor; • Actual or potential value of performance specifications; and • Conditions appropriate for the use of performance specifications. An annotated bibliography of documents is included in Appendix D. In addition, an index of existing performance specifications, collected as part of the literature review, is avail- able at the R07 report web page (http://www.trb.org/main/ blurbs/169107.aspx). how are effective performance Specifications Developed and Drafted? Historically, efforts at performance specifying (particularly in the pavement area) focused on the development and use of complex predictive models to establish specification require- ments. The research study undertaken for the R07 project adopted a more pragmatic approach that is amenable to, but not reliant on, the use of such models to define perfor- mance needs. The step-by-step process balances user needs and project goals against available technology and industry’s appetite for assuming performance risk, recognizing that such factors are often closely tied to the selected project delivery method. As illustrated by the suite of guide performance specifications prepared under this research study, the inherent flexibility of this approach makes it readily adaptable to different project elements and delivery methods. The complete performance specification development pro- cess is presented in the specification writers guide, Chapter 2. Agencies are encouraged to use the implementation guide- lines in conjunction with the guide specifications to tailor per formance requirements to project-specific conditions. Alter natively, agencies may develop additional performance specifications for needs not addressed by the current set of guide specifications. Specification Development Framework The primary function of a specification, whether prescriptive or performance oriented, is to communicate a project’s require- ments and the criteria by which the owner will verify confor- mance with the requirements. In this respect, performance specifications are similar to conventional method specifica- tions. Where they differ is the level at which performance must be defined. Figure 2.1—which was adapted from a model devel- oped by the Netherlands Ministry of Transport, Public Works, and Water Management—illustrates the possible requirement levels for a hypothetical pavement project (van der Zwan 2003). Taken as a whole, the pyramid depicted in the figure is intended to represent the entirety of knowledge and expe rience related to pavement design and construction. Taking and evaluating each level individually, the specifier can create a specification that is entirely prescriptive (if based solely on the material and workmanship properties defined on the lowest levels) or one that is more performance oriented (if based on the user needs and functional requirements described on the higher levels). For a particular project, the appropriate mix of perfor- mance requirements is driven by the project’s scope and objectives as well as the chosen project delivery approach and risk allo cation strategy. In practice, specifications typically include elements from several of the levels shown in Figure 2.1. Determining the appropriate balance between prescriptive and performance-oriented requirements is one of the main objectives of the eight-step specification development pro- cess illustrated Figure 2.2. Chapter 2 of the specification writ- ers guide describes this specification development framework in detail, systematically leading a specifier through each step in the process. However, as suggested by a review of the guide

14 specifications themselves, some steps are more critical to certain topic areas than to others. For example, although project deliv- ery approach (Step 3) plays a large role in shaping the develop- ment of a performance specification for pavements and bridges, it has less influence on establishing performance requirements for work zone management and geotechnical features. Application of the Performance Specification Framework To apply this framework to the main research areas of pave- ment, bridges, geotechnical systems, and work zone man- agement, the team first reviewed a cross section of existing performance specifications obtained through the literature review effort. Coordination with other SHRP and FHWA research projects provided additional information on topic areas that complemented the R07 effort to develop perfor- mance specifications for rapid renewal. The relevant projects addressed the following topics: • Advances in nondestructive testing techniques {e.g., SHRP 2 R06; FHWA Transportation Pooled Fund study [Project No. TPF-5(128)] on intelligent compaction}; • Innovative materials (e.g., SHRP 2 R19A); and • Mechanistic-based performance prediction (e.g., FHWA research study DTFH61-08-H-00005). The team carefully reviewed the collected literature, filter- ing existing performance specifications through the criteria established in the specification development framework to identify viable performance parameters and measurement strategies. Existing performance measures that met the frame- work criteria formed the basis for initial brainstorming ses- sions conducted among the team’s internal experts. Those existing measures, coupled with the team’s own project expe- rience, led to the development of draft performance require- ments which were then discussed and reviewed with external representatives from agencies and industry in formal work- shop settings. The input from external experts was used to refine and finalize the guide specifications and asso ciated commentary. Chapter 3 provides a more detailed summary of the findings from the literature review and outreach efforts in the context of the development of the guide specifications. To develop specifications that would be suitable for adop- tion by AASHTO, to the extent possible, the team adhered to the principles set forth in the National Highway Institute (NHI) Course No. 134001, Principles of Writing Highway Construction Specifications, and the FHWA Technical Advi- sory, Development and Review of Specifications (FHWA 2010). Even so, the team recognized that the typical AASHTO five- part format (Description, Materials, Construction, Measure- ment, Payment) may not be appropriate for every project delivery approach. For example, the lump-sum nature of a design-build contract may make measurement and payment sections unnecessary, whereas a warranty provision would require additional requirements related to bonding, distress evaluations, and required remedial action during the war- ranty period. Source: van der Zwan 2003 Figure 2.1. Pyramid of performance.

15 Figure 2.2. Performance specification development process.

16 Why Use performance Specifications? Successful implementation of performance specifications will likely require a departure from traditional project development and delivery processes. To gain support for necessary changes, best practice suggests first establishing a compelling business case as to why performance specifica- tions represent a desired addition to an agency’s contracting toolbox. Literature Review To establish the rationale for using performance specifica- tions, the team first performed a literature review to docu- ment any prior efforts to identify the actual or potential value received through the use of performance-based, incentive- based, and performance warranty contracts and specifica- tions in the highway construction industry. Recognizing that performance specifications have not been widely applied to transportation projects in the United States, the team expanded its literature search to include research and practice from outside the highway industry. For example, the use of performance-based service contracts has become a standard business practice for some federal agencies, such as the Department of Defense (DoD), and the benefits of these contracts have been validated by research studies and best practice guides (OFPP 1998a; OFPP 1998b; DoD 2000). Although the benefits may not directly translate to the value added or lost by applying performance specifications to a highway construction project, they do provide general insight into the advantages of using performance contracting strategies. Value Assessment Research and practice, particularly from outside the highway industry, suggest that implementing performance specifica- tions has the potential to provide several advantages, includ- ing decreased life-cycle costs, reduced inspection, and improved quality and customer satisfaction. However, the literature contains little data quantifying the actual value added or lost by implementing performance specifications. Despite the lack of quantitative data, the literature does reflect the perception that using performance specifications or a performance contracting system will result in enhanced value (or performance) for highway agencies and road users. The literature also makes evident that these enhancements can be attributed, at least in part, to alternative project delivery systems that provide more flexibility and shift more responsibility to the private sector to achieve perfor- mance goals. Comparative Framework The team felt it was necessary to develop a comparative struc- ture to assess performance specifications against a benchmark. That comparison would allow consideration of how project delivery approaches could affect the actual or potential value received from implementing performance specifications. On the basis of the literature review and consultation with subject matter experts, the team generated a list of viable delivery schemes for performance specifications. The results of that effort led the team to use the following delivery meth- ods as the basis for assessing the perceived value of perfor- mance specifications: • Prescriptive (method) specifications (benchmark); • Design-bid-build, with some performance requirements, but no warranty (DBB+P); • Design-bid-build, with short-term warranty (DBB+STW); • Design-build, with no warranty (DB); • Design-build, with short-term warranty (DB+STW); and • Design-build-maintain (DBM). Recognizing that project conditions could also affect the value received from performance specifications, the compar- ative framework considered the impact of different project characteristics such as the following: • Road class (local, state highway, interstate, toll); • Type of construction (preservation, reconstruction, new construction); • Traffic [low, moderate, or high annual average daily traffic (AADT)]; • Location (urban, rural); • Complexity (depending on project phasing, right-of-way requirements, utilities, environmental issues, etc.); and • Climate (depending on moisture and temperature, by region). In the context of these delivery approaches and project char- acteristics, the team turned to expert participation in surveys and workshops to assess the perceived value of using perfor- mance specifications. Such nonexperimental research tech- niques were found to be applicable given the nature of the study. Factors such as delivery methods and project character- istics can be shown to affect the perceived value placed on the implementation of performance specifications on highway construction projects. However, the effect or extent of the rela- tionship cannot be determined with precision, as any one of the other factors can lead to the same or a similar effect. There- fore, the team relied on nonexperimental techniques, includ- ing surveys and documentation of experts’ comments elicited in a workshop setting, as means for data collection.

17 Delphi Analysis Although the survey method is a detailed and systematic method of data collection, response rates can be poor and the participating experts can leave out vital information. To bol- ster this technique, the team applied the Delphi method. The Delphi method is an adaptation of the survey method and is used to obtain the judgment of a panel of experts on a complex issue or topic. It is a systematic method of data col- lection and structured discussion that aims to minimize the effects of bias given the characteristic lack of anonymity in interviews and general surveys. The method is particularly useful in situations in which empirical means are not suitable and research results rely heavily on the subjective opinions of experts. In brief, a Delphi analysis entails an iterative process in which experts’ opinions are processed and used as feedback for further refinement of opinions generated in earlier sur- vey rounds. The iterative nature of the process is expected to yield more reliable results than a single survey round. The Delphi analysis required the team to (1) assemble the Delphi expert group; (2) develop and administer survey questions; (3) receive and process the survey responses; (4) conduct a structured workshop to present, discuss, and clarify the sur- vey results; (5) conduct a second survey round assessment; (6) summarize the outcomes of the Round 2 assessment, and (7) conduct a Round 3 assessment and summarize results. Appendix E provides a detailed summary of the design and results of this data collection effort. The Delphi survey results are provided in Appendix G. Demonstration Projects Perhaps the most powerful way to identify and communicate the potential benefits of performance specifications is through demonstration projects. The SHRP 2 R07 project therefore included an implementation phase designed to validate the guidelines and performance specifications developed during the research effort. The first step toward this end was to identify candidate agen- cies that would be willing to participate in a demonstration project. A survey questionnaire was developed to gauge the interest and experience of a representative sample of highway agencies in the United States, particularly those known to have experience or interest in performance specifications or alter- native project delivery methods. The survey included a brief description of the R07 project, including the project objectives and scope of the demonstration program. The survey document further explained that the team was seeking to work with two or more transportation agencies in implementing performance specifications on demonstra- tion projects to test and validate the use of performance specifications for rapid highway renewal projects. The R07 team offered to provide resources to work with agency per- sonnel to select an appropriate project or projects, develop the necessary performance specifications and contracting pro- visions, and assist with the administration of the project dur- ing design and construction, and, if applicable, during the maintenance and operation phase. Most important, the survey sought information as to (1) the likelihood that the agency would have projects suit- able for a demonstration of performance specifications in the 2010–2011 construction seasons and (2) the areas for which the agency would be most interested in performance specifying. Ten agencies returned questionnaires or sent e-mail responses indicating interest in participating in a SHRP 2 R07 demonstra- tion project. From those responses, the team identified the following projects as viable candidates for demonstrations: • Virginia DOT Route 208 Lake Anna Bridge Deck Rehabilita- tion Project—a shadow demonstration of the use of perfor- mance parameters that related more to long-term durability and performance; • Missouri DOT Route 141 Roadway Improvement Project— a demonstration of the use of nondestructive roller-integrated compaction monitoring (RICM), or intelligent compaction, to provide real-time and improved quality control of soil compaction operations; and • Louisiana DOTD U.S. Frontage Roads—a demonstration of the use of RICM and mechanistic-based in situ point measurements on a new pavement section. A more detailed discussion of these demonstrations is pro- vided in Chapter 3. What are the risks associated with Implementing performance Specifications? Risk in the context of performance specifications relates to the existence of any uncertain event or condition that, if it occurs, has a positive or negative effect on the objectives of the specification. The FHWA’s Guide to Risk Assessment and Allocation for Highway Construction Management presents a continuous, cyclical approach to risk assessment, involving the following steps: identify, assess and analyze, mitigate and plan, allocate, and monitor and update (Ashley et al. 2006). A similar approach was used to address the risks associated with performance specifications. As a key component of the specification development frame- work, the discussion of risk related to performance specifica- tions (i.e., identification and evaluation of risks) is addressed in the specification writers guide. The entire process of developing

18 a performance specification is in a sense a risk management exercise designed to identify, allocate, and mitigate the risks associated with implementing a performance specification. The generally accepted approach to project-level risk management—as described in FHWA’s Guide to Risk Assess- ment (Ashley et al. 2006) or the SHRP 2 R09 Guide for the Process of Managing Risk on Rapid Renewal Projects (Golder Associates et al. 2013)—is useful in developing a general frame- work for identifying risks; it is less useful in terms of analysis (e.g., quantifying the frequency and impacts of specification- related risks). In some cases the specification risks, such as gaps in performance measurement, are difficult to quantify given the current state of the practice (or level of understanding). For example, given the interest in the use of NDT and mechanistic properties for performance measurement, further research is needed to quantify the effects of risk related to variability or reliability of NDT versus traditional tests, or opportunities related to the use of mechanistic versus traditional perfor- mance measures. Additional long-term data collection will be needed to make valid quantitative risk assessments. The risk process described in the specification writers guide is geared to identifying risks and gaps and qualitatively deciding whether performance specifications are appropri- ate. Further, the guide assists in determining how to develop a performance specification to allocate risk among the proj- ect participants considering the current state of the practice. Further assessment of performance specification risks are needed to quantify the impacts or opportunities related to their use. When Should performance Specifications Be Used? Performance specifications are not ideal for every construc- tion contract or project circumstance. However, they may hold significant advantages over traditional method specifi- cations when certain criteria or conditions are met. To inte- grate performance specifications into an agency’s contracting toolbox, a process is needed to evaluate when to use or not to use performance specifications. The decision to use method or performance specifications is often a matter of degree (how much and at what level). Both approaches may be appropriate for specific elements within a project. In choosing the appropriate level of perfor- mance specifications, an organization’s culture, statutory restrictions, project objectives and characteristics, project delivery approach, and risk appetite all may play important parts in defining specifications. The interaction among these key factors will likely determine the preference for one type of specification over the other. The decision to use performance specifications versus method specifications can involve a relatively straightforward screening test, followed by a more in-depth analysis of the level and type of performance specifying appropriate for the project characteristics and contracting type. Thus, the imple- mentation guidelines (see the executive guide, Chapter 5) present a two-part decision process for evaluating when to use or not to use performance specifications. Part 1 of this decision process considers a project’s scope and goals. Part 2 addresses the project delivery considerations that could also affect the decision. Who Is affected by performance Specifications and how are they affected? For agency personnel, developing and implementing a scope of work in terms of user needs and end-result performance is often much more challenging and resource intensive than simply adhering to the agency’s standard specifications. For contractors, an initial investment may be needed to acquire the necessary knowledge, skills, and equipment to assume more responsibility for performance. While critical to a project’s success, a well-drafted perfor- mance specification will not in and of itself ensure that an agency’s performance goals will be met. Cultural, organiza- tional, and legal issues can also affect the successful imple- mentation of performance specifications. For this reason, the team prepared a set of implementation guidelines to accom- pany the guide specifications. In doing so, the team reviewed the existing literature, had discussions with practitioners from agencies and industry, and identified lessons learned from the demonstration projects. The goal was to address the following considerations: • The effect the decision to use performance specifications could have on an agency’s traditional project delivery phases, from project planning and preliminary engineering through to construction completion and possibly beyond to mainte- nance and asset management; • Any natural progression or transition from more traditional contracts and specifications that should precede the deci- sion to use performance specifications (i.e., a learning curve to attune both the agency and industry to a new business model); and the • General mechanics of administering performance con- tracts (e.g., procurement process, document and database management, and so on). This information, along with the key takeaways drawn from the other research tasks, was incorporated into both the imple- mentation guidelines and the guide specifications, as applica- ble, to provide agencies with the tools needed to develop and successfully implement performance specifications.

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TRB’s second Strategic Highway Research Program (SHRP 2) Report S2-R07-RR-1: Performance Specifications for Rapid Highway Renewal describes suggested performance specifications for different application areas and delivery methods that users may tailor to address rapid highway renewal project-specific goals and conditions.

SHRP 2 Renewal Project R07 also produced:

A separate document, Guide Performance Specifications, includes model specifications and commentary to address implementation and performance targets (for acceptance) for 13 routine highway items. Agencies may adapt guide specifications to specific standards or project conditions. The commentary addresses gaps, risks, and options.

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