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January 23, 2018 Ms. Brandye Hendrickson Acting Administrator Federal Highway Administration 1200 New Jersey Ave., SE, Room E87-312 Washington, D.C. 20590 Dear Acting Administrator Hendrickson: The committee for the Review of Federal Highway Administration (FHWA) Infrastructure R&D Program met on November 29-30, 2017, in Washington, D.C., in an inaugural meeting to be briefed on the Long-Term Infrastructure Program (LTIP) by FHWA staff. The committee members who attended the meeting are listed in Attachment A. The charge to the committee is to âadvise the Federal Highway Administration (FHWA) Infrastructure R&D Program regarding priorities in terms of the technical tools and products that state departments of transportation need to maintain and improve the performance of their pavements, bridges, and other structures.â The committee was established to provide an ongoing review of the LTIP based on annual meetings with FHWA staff and stakeholders. The committee will issue an annual letter report with its recommendations on priorities for the LTIP. The first meeting was structured around a series of briefings on the two components of the LTIP: the Long-Term Pavement Performance (LTPP) program and the Long-Term Bridge Performance (LTBP) program. The meeting agenda appears in Attachment B. Each briefing provided ample time for the committeeâs questions and discussion. On the second day of the meeting, the committee held a closed session to develop its recommendations. The recommendations and letter report were subsequently developed through correspondence. On behalf of the whole committee, I would like to thank Cheryl Richter, Jean Nehme, and their entire staff for a very constructive set of briefings and subsequent discussion. In this letter I provide an overview of what the committee heard about the LTIP, issues that were raised during the discussion, and our recommendations for strengthening the LTIP effort. LONG-TERM INFRASTRUCTURE PROGRAM OVERVIEW The LTIP combines the LTPP and the LTBP under a single management structure. One program, the LTPP, has a 25-plus-year legacy of data collection on pavement performance. The second program, the LTBP, is much younger by comparison. Although it has collected performance data on a few bridges in the sample, it will initiate nationwide data collection on the full sample of bridges in 2018.
2 In this section we summarize our understanding of these programs and the issues that they face based on the presentations made at the meeting and the materials provided to the committee. Long-Term Pavement Performance Program Conceived and initiated as part of the first Strategic Highway Research Program (SHRP) in 1987, the LTPP has been managed by FHWA since 1992. It is the worldâs largest ongoing experiment to explore pavement performance and the causes of deterioration by taking into account the effects of climate and loads on pavements of differing designs and materials. Data collection categories include climate, traffic volumes and loads, pavement layer type and thickness, material properties, and pavement condition (distress, longitudinal and transverse profile, and structural evaluation). Some of these data are collected centrally while others are the responsibility of the participating states or provinces.1 The need for a long-term pavement performance program was first raised in Americaâs Highways: Accelerating the Search for Innovation.2 This report, prepared by a panel of senior leaders in the transportation community, noted that highway pavements were not always living up to design expectations and recommended a âlong-term field test that systematically covered a wide range of climate, soil, construction, maintenance and loading conditions.â In response to this recommendation, in 1986, the American Association of State Highway and Transportation Officials (AASHTO) developed the design for such a program to be included in its plans for SHRP, which had support from the materials industry. Congress funded SHRP as part of federal aidâhighway authorizing legislation in 1987. The LTPP data collection began in 1989. In 2001, the LTPPâs mission was described as fostering increased pavement life through the â¢ Collection and storage of performance data from a large number of in-service highways in the United States and Canada over an extended period to support analysis and product development; â¢ Analysis of these data to describe how pavements perform and to explain why they perform as they do; and â¢ Translation of these insights into products for pavement design, rehabilitation, maintenance, and management.3 As a result of constrained resources, the programâs mission has narrowed over time to mostly focus on data collection, storage, support of analysis, and some original data analysis. At its peak, the program was collecting data on more than 2,500 test sections in the United States and Canada.4 Today the program continues to collect data on 436 test sections. About half of the remaining sample are sections of pavement that were added to the program after they were designed and constructed, referred to as General Pavement Studies (GPS). These segments were carefully selected to encompass the range of factors believed to affect pavement performance. Most remaining GPS segments are asphalt concrete overlays of asphalt concrete pavements, but there are also many 1 TRB (Transportation Research Board). 2001. Fulfilling the Promise of Better Roads. A Report of the TRB Long-Term Pavement Performance Committee. National Academy Press, Washington, D.C. 2 TRB Special Report 202: Americaâs Highways: Accelerating the Search for Innovation. TRB, National Research Council, Washington, D.C., 1984. 3 TRB. 2001. Fulfilling the Promise of Better Roads. A Report of the TRB Long-Term Pavement Performance Committee. National Academy Press, Washington, D.C., p. 4. 4 Information about the LTPP program in the remainder of this section is summarized from FHWA. Long-Term Pavement Performance Program. Publication No. HWA-HRT-15-018 HRDI-30/12-14(1M)E.
3 jointed concrete pavements in the GPS sample. The other half of the remaining test sections were built to LTPP program specifications to assess the performance of specific designs and thicknesses, referred to as Specific Pavement Studies (SPS). Most remaining SPS sections were established to assess the impact of structural factors on rigid pavement performance or pavement performance in the absence of heavy loads. Critical to the success of the LTPP has been the collection of accurate and consistent data characterizing pavement structures (layer thicknesses and materials), environmental conditions, traffic loads, and indicators of pavement condition. The LTPP developed a series of protocols for instrument calibration and data collection to ensure research-quality data, including both physical data (cores taken of pavements) and electronic data on loads and climate conditions. The enormous data set (just under 9 terabytes) is archived in the cloud and served by several high-capacity servers. FHWA has made the data accessible to analysts and researchers through a website (InfoPave) that provides readily defined and downloaded data sets. Also critical to the success of the program has been a well-structured analysis plan that lists the strategic objectives of the program and the projects that support the accomplishment of those objectives. Long-Term Bridge Performance Program According to information provided to the committee by FHWA, âThe LTBP Program is a [FHWA] long-term research effort to collect high-quality bridge data from a representative sample of highway bridges nationwide that will help the bridge community to better understand bridge performance.â5 The program was authorized in the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), which was enacted in 2005.6 The program has several goals, including to â¢ Improve long-term knowledge of bridge performance. â¢ Provide opportunities to assess and develop advanced deterioration and predictive models that incorporate various data sources. â¢ Support the development of improved design methods and maintenance/bridge preservation practices. â¢ Quantify the effectiveness of various maintenance, repair, and rehabilitation strategies. â¢ Promote the next generation of bridge management systems through the implementation of data-driven approaches. â¢ Allow bridge owners to make better data-driven decisions in managing their bridge inventory through improved understanding of bridge performance. The data collection effort focuses on three common bridge designs: (1) steel multi-girder, (2) prestressed multi-girder, and (3) prestressed/post-tensioned concrete box girder. The sample is made up of 14 clusters of bridges in multiple states that span various climactic zones and 10 major north- south and east-west interstate highway corridors. For each cluster, two to four representative bridges 5 FHWA. Long-Term Bridge Performance (LTBP) Program. Publication No: FHWA-HRT-18-008 HRDI-30/11-17(1.5M)E. 6 Information provided in the remainder of this section is summarized from presentations made to the committee and the LTBP website: https://www.fhwa.dot.gov/research/tfhrc/programs/infrastructure/structures/ltbp/index.cfm.
4 will be selected as âreference bridges.â These bridges will be assessed every two years using non- destructive evaluation (NDE) technologies and detailed hands-on visual inspections until accurate deterioration models can be validated. A few of these bridges will also be instrumented to assess overall structural response. FHWA has collected âlegacyâ data (mainly from as-built construction plans and maintenance records) on reference and cluster bridges. The final sample size will depend on program resources, but is envisioned to be approximately 1,000 bridges. Currently, the program is collecting legacy data on about 500 bridges. Based on interactions with state department of transportation (DOT) bridge engineers, the LTBP program is focusing its efforts in six areas: 1. Untreated bridge decks, 2. Treated bridge decks, 3. Bridge deck joints, 4. Bridge bearings, 5. Coatings for steel superstructure elements, and 6. Condition of embedded pretensioned strands and post-tensioned tendons. As program plans have been developed, FHWA has also invested in developing tools for conducting NDEs of bridge decks to identify corrosion and delamination that are not apparent from visual inspection using protocols that ensure repeatable results for modeling purposes. FHWA has invested in the development of the RABITâ¢ bridge deck assessment tool, which combines five different NDE measures in a faster and more efficient fashion than collecting these data separately. Development of this technology has occurred over several years. FHWA recently acquired several RABITsâ¢ to collect NDE data on bridge decks during 2018 after new contractor staff are trained in the use of this technology. In order to ensure the consistency of the data collection, FHWA prepared several protocols for NDE data collection and is preparing protocols for determining overall structural response, assessment of decks with overlays, and assessment of superstructures. All of the data collected are intended to be made available to analysts and researchers through an FHWA portal. Currently, very few people have access to the data due to difficultly reaching them through the FHWA firewall. Included in the data portal are LTBP field data, National Bridge Inventory (NBI) data, limited National Bridge Elements (NBE) data, traffic data, records of maintenance and preservation, and weather data. COMMITTEE DISCUSSION Asset Management Committee members agreed that the LTIP is very important to state DOTs. Major concerns for most states are (1) how to extend the life of existing assets and (2) how to improve data for predictive models, and the models themselves, to better estimate when assets need maintenance and when they require rehabilitation or replacement. Existing models allow states to plan ahead and allocate resources needed to keep pavements and bridges in good repair to maximize service life. Many of these models, however, are based on assumptions or on data of limited quality. LTPP data, which are collected consistently because of FHWAâs protocols and are of high quality, are already helping
5 states calibrate models for pavements, but similar performance data are lacking for bridges. In smaller states, underestimated maintenance and repair for a major bridge can completely distort annual and five-year investment plans. Committee members appreciated the value of LTPP data and recognized that it will take time to collect bridge data. The members were already quite anxious to have such data on bridges, however, and urged LTIP staff to accelerate their efforts to begin collecting planned NDE data on untreated bridge decks. Partnerships with States During the presentations, FHWA staff indicated that due to constrained funding, the LTPP program would be able to fund only one annual project devoted to data analysis. LTIP staff were pleased and grateful that AASHTOâs Standing Committee on Research (SCOR) recently agreed to allocate funding for five National Cooperative Highway Research Program (NCHRP) projects to analyze LTPP data. LTIP staff also noted that up to 15 percent of the bridge deck NDE data collection budget will be needed to provide traffic control while data are being collected. Committee members recalled that state DOTs have provided traffic control to the LTPP program and also installed weigh-in- motion systems to provide data on traffic and loadings. Members indicated that many states are likely to be willing to provide traffic control to NDE bridge deck data collection so that more of the LTBP budget can be devoted to data collection. Outreach Committee members suggested that the LTIP has many potential partners: states, universities, professional associations, and industry associations. These potential partners, however, need to understand the programs and what they are trying to accomplish, particularly the LTBP because it is a much less mature program than the LTPP. Members urged FHWA to reach out to appropriate AASHTO committees to brief them on the programs and seek support and assistance. With regard to AASHTO, it is important to reach out to state chief executive officers and chief engineers because they are the ones who allocate resources. Committee members volunteered to assist in this effort. Bridges as Systems Committee members discussed the importance of gaining a better understanding of how bridges perform over time. In consultation with the states, FHWA made its first priority the collection of NDE data on untreated bridge decks. Members agreed that decks are a priorityâmost of the deficiency ratings for bridges in the NBI are due to deck condition and decks represent a major share of state bridge maintenance and repair spending. However, bridges are more complicated than pavements because the deck, superstructure, and substructure interact and each has many interdependent components. State DOTs would like to understand and be able to manage the life cycle of the whole bridge, but this is not possible with current predictive models and data. Moreover, there is some risk in looking at decks in isolation of the performance of the whole bridge. Although the committee recognized that visual inspections will be done on bridge sub- and superstructures for those bridges for which NDE deck data are gathered, visual inspection of sub- and superstructures falls short for the same reasons it falls short of providing a full picture of the deck condition. Committee members understood the resource limitations that drive FHWA to begin with deck data
6 collection, but believed that the agency needs a long-term vision for how to gather information on bridges holistically. Committee members also discussed whether the LTBP program should be assessing the risk of rare extreme events of bridge failures, which would certainly include gathering more extensive data on the condition of sub- and superstructures. Members, however, concluded that states have robust, ongoing inspection programs for this purpose and that NCHRP has several projects addressing this area. Avoidance of Scope Creep Given the limited resources for data collection, committee members agreed that it is important for the LTBP to begin with the priorities identified in consultation with state bridge engineers and focus its initial efforts on collecting the data that states want and need. Members also recognized that this effort will take time. Data are available today on pavements because DOTs recognized almost 30 years ago that pavements were not performing as designed or expected and much better data on field performance were required. Recognizing that many needs for understanding bridges are going unmet, members stressed that it is nonetheless important for the LTBP program to define its mission and objectives and stick to them, much as the LTPP program has had to do. Experimentation with New Materials The committee understood that the LTPP and the LTBP must focus on gathering performance data on pavements and bridges built with the most common types of materials, but they also noted that states are experimenting with all sorts of new materials for which it would be valuable to have performance data. Because of this ongoing experimentation, committee members were disappointed with FHWA staff statements that LTPP data collection is âwinding downâ to a point where data collection will end, although some data analysis will continue and access to the data will be maintained. Members suggested that perhaps it is better to not plan for the LTPP program to wind down completely. The committee encouraged FHWA to consider a model where FHWA would develop protocols and states would collect data, which would then be stored in FHWAâs national database and be made accessible for researchers and state analysts. Pooled-fund studies to evaluate the performance of innovative materials would be a possibility in this regard. In addition, states cooperate regionally on evaluating new techniques and materials. Members suggested that it would be useful for FHWA to find out what these regional groups are working on and how these efforts might be coordinated with the LTIP. Data Access Committee members voiced strong support for FHWAâs approach to open access to pavement data through the InfoPave website. In order for research, analysis, and model development to move forward expeditiously, it is essential for researchers and analysts to have access to the complete pavement data set. FHWAâs presentation on access to bridge data noted that some of the bridge data being collected have security concerns and currently require individuals seeking access to the data to be screened before access is granted. Committee members recognized that security concerns may cause some data to be restricted. There was a strong sentiment, however, to make as much data as possible openly accessible.
7 RECOMMENDATIONS In the current resource-constrained environment, which is expected to continue, state DOTs are anxious to have the best possible short- and long-term asset management and budget plans for extending the life of their existing assets. Better measures of long-term performance will improve predictive models, optimize funding allocation, and strengthen long-range planning for asset replacement. The LTIP provides an ideal opportunity for obtaining highway pavement and bridge performance information in a consistent and efficient way that avoids states possibly duplicating their existing efforts. The committee is highly supportive of the LTPP and the LTBP. The LTPP program is already providing fundamentally important performance data about pavements. The LTBP program can fill a significant gap about long-term bridge performance. The goal of these programs should be to help states make better, data-driven decisions about designing and managing their assets. Also, because state DOTs currently have a strong focus on innovation, FHWA can ensure that the LTIP program remains relevant to the needs of these agencies by supporting their innovative practices through the LTIP data collection efforts. Recommendation 1 FHWA should develop a strategic plan for the LTPP and the LTBP. The committee viewed this as the most important next step. This plan should have several elements: a. It should be clear and bold about the vision and mission of the LTPP and the LTBP, the data that are essential for meeting statesâ needs, and not be constrained by the current program budget. FHWA, of course, should be prepared to adjust its priorities based on funding availability through FHWA R&D and through partnerships with state DOTs and others. b. It will also be important for FHWA to have a risk management plan to address uncertainties about future funding, both for FHWAâs contribution and the possibility of obtaining funding through partnerships. c. The plan should integrate the LTPP and the LTBP into the LTIP and articulate the synergies obtained from placing these activities under unified management. d. The plan should have a short- and long-term perspective. Its short-term focus should be on accelerating the collection of bridge NDE data. Its long-term vision should include expanding bridge performance collection to bridge sub- and superstructures. e. The planâs short-term elements should be complete enough to define the specific tasks and milestones for the strategies being pursued for achieving objectives, as well as the expected outcomes, deliverables to state DOTs, and expected schedule of delivery. This level of detail will be needed to clarify and define what the program needs from states and other partners, such as traffic control at data collection sites and approximately when this assistance will be needed. The plan should also identify the expected outcomes and timelines for its long-term elements.
8 f. The committee recognized that the LTPP program is mature and winding down as data collection from remaining test sections is completed, but the plan should articulate a longer- term vision for additional data collection. The LTIP is a unique and valuable program for collecting long-term performance data. State DOTs are continually adding new materials into their pavement and bridge designs, for which the LTIP is an ideal model for data collection. State pooled-fund projects and other approaches should be considered for funds to support needed data collection. Recommendation 2 FHWA should raise the profile of the LTIP both internally and externally. The preparations for the next reauthorization of surface transportation programs provide an opportunity to make a strong case for the program. A compelling strategic plan can guide this opportunity to enhance awareness about LTIP to policy makers. AASHTO members can support R&D and data collection programs because of their compelling interest in asset management. Committee members were willing to assist in this process once a well thought-out and compelling strategic plan is available. Recommendation 3 FHWAâs outreach should include a variety of key existing and potential partners: a. In addition to working with AASHTO committees and subcommittees with a strong interest in performance data, it is essential that FHWA reach out to state DOT officials with responsibility for resource allocation with a clear, succinct message about the goals of the LTIP and how it will help states manage their assets. At its outset, the LTPP had AASHTO, industry, and FHWA behind it. FHWA needs to rebuild that for the LTPP and build that for the LTBP. Part of this outreach should be explaining the importance and goals of the programs and part of it should be about the specific areas of assistance from which the LTIP program could benefit. Some, if not many, states are likely to be willing to help individually through their state planning and research funds and collectively through pooled-fund projects. b. In order to advance data analysis that FHWA cannot fund on its own, FHWA should also reach out to professional societies and University Transportation Centers to make users aware of the programs, data resources, and research opportunities. Recommendation 4 FHWA R&D managers should define a specific LTBP mission and avoid the tendency for scope creep. The emphasis ought to be on data collection, with a sense of urgency about collecting as much high-quality data as possible. NCHRP is primed to develop deck predictive models7 and states are likely to want to tailor or develop models to their circumstances. FHWA should design data collection to be compatible with the models NCHRP is developing in anticipation of having LTBP data available. 7 See, for example, NCHRP 12-108, Guide Specification for Service Life Design of Highway Bridges. http://apps.trb.org/cmsfeed/TRBNetProjectDisplay.asp?ProjectID=4040.
9 Recommendation 5 FHWA should develop a basic definition of bridge performance as a system. The committee believes that it is appropriate to focus on decks initially because expenditures on bridge decks represent a significant portion of state bridge maintenance and repair spending. States also lack data to calibrate predictive models for deck performance. Bridges are systems, however, and decks interact with the sub- and superstructures. The strategic plan needs to show how the program will ultimately address the entire bridge as a system. Recommendation 6 The committee understood the sensitivity of some bridge information and that policies and procedures will need to be developed and implemented to address this, but the goal should be to strive for a similar level of accessibility for bridge performance data as what is provided through InfoPave. This is necessary in order for researchers and model developers to accomplish their work most effectively. It may be necessary to have a system of restricted access for researchers to obtain the most sensitive data. Even though relatively little LTBP deck performance data are currently available, it will take time to work through access policy issues and procedures; thus, this work should be initiated soon. CLOSING In closing, I would like to again compliment the FHWA staff on the quality of their presentations and discussion with the committee. Speaking on behalf of the committee, we look forward to continuing to assist FHWA with its important and valuable programs to assist state DOTs. Sincerely, Thomas Sorel Committee Chair Attachments A. Meeting Attendees B. Meeting Agenda
10 ATTACHMENT A TRB Long-Term Infrastructure Performance (LTIP) Committee Meeting November 29-30, 2017 National Academiesâ Keck Center Room 208 Washington, DC Meeting Participants Committee Thomas K. Sorel, Chair, North Dakota Department of Transportation, Bismarck, ND Courtney Drummond, Florida Department of Transportation, Tallahassee, FL Matthew M. Farrar, Idaho Department of Transportation, Boise, ID Dan M. Frangopol, Lehigh University, Bethlehem, PA Gregg C. Fredrick, Wyoming Department of Transportation, Cheyenne, WY (by conference call) Mostafa Jamshidi, Nebraska Department of Transportation, Lincoln, NE Bruce V. Johnson, Oregon Department of Transportation, Salem, OR Patricia Leavenworth, Massachusetts Department of Transportation, Boston, MA Rebecca S. McDaniel,* Purdue University, West Lafayette, IN Kumares C. Sinha, Purdue University, West Lafayette, IN Joyce Taylor, Maine Department of Transportation, Augusta, ME James A. Williams III, Mississippi Department of Transportation, Jackson, MS * Not able to attend. FHWA (in person or by conference call) Fred Faridazar Jamie Harris (FHWA LTIP contractor) Joey Hartmann Frank Jalinoos Jane Jiang Hari Kalla Jean Nehme Cheryl Richter Jack Springer Mark Swanlund Deborah Walker Larry Wiser Robert Zobel Liaisons Audrey Copeland, National Asphalt Pavement Association, Lanham, MD Waseem Dekelbab, TRB/NCHRP Amir Hanna, TRB/NCHRP TRB Project Staff Stephen Godwin Amelia Mathis Thomas Menzies
11 ATTACHMENT B Agenda TRB Long-Term Infrastructure Performance (LTIP) Committee Meeting National Academiesâ Keck Center, Room 208, Keck Building 500 Fifth St., NW, Washington, DC 20001 November 29-30, 2017 The purpose of this meeting is to communicate and receive feedback on FHWA's goals for its investment in the long-term Infrastructure Research and Technology Program and the agencyâs plans for achieving those goals, inform/update committee members of current and past activities of the Long-Term Bridge and Long-Term Pavement Programs, and identify and discuss issues affecting program success. Wednesday November 29, 2017 08:30-9:30 Closed Session for Committee Composition and Balance Committee and staff 09:35-9:45 Opening Remarks Tom Sorel 09:45-10:00 FHWA Leadership Updates FHWA Leadership 10:00-10:20 Break 10:20-10:40 FHWA Infrastructure Priorities Presentation of FHWA's overall infrastructure priorities. Cheryl Richter 10:40:11:20 Overview and Current Status of the LTPP and LTBP Programs Jean Nehme 11:20-12:00 LTBP Data Collection and Current Status Update Robert Zobel 12:00-1:00 Lunch in cafeteria 1:00-2:00 LTBP Data Analysis Plan and Current Status Update Frank Jalinoos Robert Zobel 2:00-2:40 LTPP Data Collection and- Current Status Update Jack Springer 2:40-3:00 Break 3:00-3:40 LTPP Data Analysis Plan and Current Status Update Larry Wiser 3:40-4:10 LTBP Bridge Portal â Uses and Demonstration Robert Zobel 4:10-4:40 LTPP InfoPave â Uses and Demonstration Jane Jiang 4:40 â 5:00 Recap Jean Nehme 5:00-5:30 Committee Closed Session Committee and staff 5:30 Adjourn for Day