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TRANSPORTATION RESEARCH BOARD OF TtlE NJATIO¡VAL /aICÃDF¡/'|JES March 16,2012 Mr. Victor M. Mendez Administrator Federal Highway Administration U.S. Department of Transportation 1200 New Jersey Avenue, SE HOA-1, Room E87-314 Washington, DC 20590-9898 Dear Mr. Mendez: Re: 1st letter report of the TRB Lonq-Term Bridge Pedormance (LTBP) Committee I am writing to report the findings and recommendations of the Transportation Research Board (TRB) LTBP Committee that were developed at its meeting on November 28-29, 2011. The committee's membership roster is attached. The LTBP program is a long-term (20+ years) undertaking begun by the Federal Highway Administration (FHWA) in 2008. lts purpose is to address the challenges being faced by federal, state, and local transportation agencies in the operation and maintenance of their aging and deteriorating highway bridges. The objective of the program is to collect research-quality data on a large representative sample of in-service U.S. highway bridges and to analyze these data to improve understanding of the mechanisms and timing of bridge deterioration due to the effects of age, materials, traffic, and weather. The data collection and analysis will also help in evaluating the effectiveness of intervention options in ameliorating this deterioration. Through a contractual arrangement with FHWA, the National Research Counc¡l (NRC) provides advice and assistance on the conduct of the LTBP program through the work of its TRB LTBP Committee. The agendal of this kickoff meeting consisted of briefings by TRB staff, FHWA staff, and FHWA contractors, each followed by a question-and-answer period and discussion. The topics included the role of the committee (its structure, how it will operate, and the process of consensus development), an overview of the LTBP program (its background, status, and budget), the LTBP research plan (definitions and measurements of performance), data collection (the first years and lessons learned), and the road ahead (LTBP data infrastructure, data analysis, and products). 1 See Attachment 1. THE NATIONAL ACADEMIES 500 Fifth Street, NW Phone (202) 334-2934Washington, DC 20001 Fax (202) 334-2003 www.TRB.orgddvrers fo ffte f{ot¡o¡ on 5ænre, EngÃneerlng ondûîednme
At the conclusion of these open sessions, the committee held a closed session to deliberate on its findings and formulate its consensus recommendations, which are summarized here: o [LR01/01]2 We thank the members and contractors of FHWA's LTBP program ("the program") for their extensive efforts in preparation for this initial meeting of the committee. Their briefings were detailed and highly informative, and they provided us with a comprehensive introduction to the program. Now that the committee has been established, we look fo¡ward to supportinq this effoñ by offerin,q comments and suqqestions for proaram improvement for FHWA's consideration. We trust that this first meetinq and Ietter report are iust the beginnin,a of a lons and fruitful collaboration. o [LR01/02] The briefing materials present graphically a wealth of information about the program that would be much more valuable to program stakeholders and the public if they were translated into concise prose. One way of explaining LTBP concisely as part of this prose is as follows: "LTBP's goal is to foster improved bridge performance, health, and stewardship and management through the analysis of data collected over a 2}-year period on a large representative sample of U.S. highway bridges. To achieve this goal, the program is designed to produce or support improved deterioration models, reliable life-cycle cost and forecasting models, design procedures, and decision-making tools." We suqqest that LTBP's aoals. and the objectives to be achieved to reach these aoals, be stated conciselv. The statement should also connect the qoats and obiectives to the work that has been undertaken since 2008 and to the plans for new work that are now beinq developed- o [LR01/03] The period from 2009 to 2011 was a pilot phase of LTBP. Protocols and procedures for data collection and data storage and analysis were developed and validated, testing methodologies were refined, and data collection began on a set of seven pilot bridges. This phase is coming to a close, and a draft report is being edited. The experiences gained in and the results of inspecting, instrumenting, testing, and monitoring these bridges will be major determinants in the design of the larger program for 2 Each recommendation is given a unique designator of fletter report numberirecommendation number] to facilitate future referencing. 2
long-term data collection and analysis. We look forward to receivinq the repoñ of this pilot test and learninq how the experience qained therefrom is translated into plans for qatherinq and analvzin,g the data to be collected on the program's larqer set of bridqes. The sooner we receive this report, the sooner we will be able to offer suqqestions concerninq the desi,an of the larqer study. We request receipt of other related repofts that are beinq drafted on pertormance issues. cluster and reference methodoloqy. and samplinq methodolosv. Furthermore. we encouraqe a qeneral release of these reports- [LR01/04] The LTBP staff and contractors conducted a comprehensive examination of the factors affecting bridge performance and mounted a number of outreach efforts (focus groups across the United States, a workshop on geotechnical issues, the LTBP state coordinators meeting, and others) to identify and prioritize performance issues. This effort has culminated in a list of more than 20 high-priority performance topics, and five of them have been proposed for initial study, all pertaining to new construction: - Performance of untreated concrete bridge decks, - Performance of bridge deck treatments, - Performance of bridge deck joints, - Performance of bridge bearings, and - Performance of coatings for steel superstructure elements. We concur with the selection of these five topics but suqgest that "pertormance of foundation scour countermeasures" be added to the list because scour is a leadinq cause of brid'ge failure. Fuñhermore. we recommend that the studv include bridqes of all aqes that are likely to remain in seruice throuqhout the lifetime of the proqram. The proqram must collect and anal:/ze pefformance data aathered throuqhout the seruice tife of the bridses beinq studied. and thus their early years are as important as their later vears. However. the studv of bridaes whose deterioration beqan before initiation of the proqram is equallv important. Concentratino on new construction alone would iqnore the reality that many "old" bridqes will remain in seruice for extended periods of time. Selective data mininq of existinq databases such as the National Bridqe lnventory useful i and what data to collect and analvze.
[LR01/05] Stakeholder access to information about LTBP and its data is a critical component of the program and can be its principal product. The "bridge portal" is the key mechanism for providing this access. This lnternet portal will not only support the development of the program's information management system but also facilitate data exchange with and delivery to the bridge communitY. We understand that the poftal is beinq beta tested bv some state departments of transportation and FHWA offices while Version 2.0 is under development. We recommend that this testinq be expedited and that the fullv vetted version be made operational and released. The state depaftments of transportation should be aleñed sufficientlv far in advance of the public release. so that thev can prepare for the questions from the public and the press that mav ensue. In addition. to sustain state suppott of LTBP, we recommend that the proqram's data collection protocols be provided to the states. We recoqnize that these protocols mav have to be rewritten to be usefulto those outside of LTBP, but this product development and dissemination work witt vietd many benefits to the prosram in terms of stakeholder suppott. ILRO1/06] The LTBP staff and contractors recognize the importance of outreach to the success of the program. Keeping the states and other stakeholders ¡nformed of the program's progress and seeking feedback with regard to their needs and expectations will continue as high-priority activities. meetinqs of the AASHTO Reqional Bridqe Preseruation Pañnerships. We recommend that outreach activities be expanded to encompass the use of state visits bv LTBP personnel, Accelerated Bridqe Construction Center webinars. LTBP newsletters and webinars, and results-oriented LTBP state coordinators meetinqs, allon a regular and predictable schedule throuqhout the vear. [LR01/07] FHWA has requested the formation of three expert task groups (ETGs) to support our review of the program and development of consensus recommendations. The ETGs will be full-fledged NRC advisory committees. They will hold periodic meetings with LTBP staff and contractors to receive briefings on specific technical issues and to deliberate on the findings and advice that they will submit to us as part of meetinos of the American Association of State Hiqhway and Transportation Officiats (AASHTO\ Subcommittee on Bridqes and Structures, and
our information-gathering activity at each of our meetings' Each ETG will have a specific subject aÃea'. - Bridge durability and preservation, - Bridge evaluation and monitoring, and - Bridge traffic and truck weights. in time to hold their first meetinqs at least 2 weeks before our next meetino 2012. so irs will time In ciosing, we recognize ihat the preparations for this meeting i'equired e><tensive eflort by many peóple, and we express our thanks to them individually and collectively. The LTBP team functions well and has a common purpose-to ensure the success of the LTBP program. We willingly join the team and enthusiastically support the purpose. Finally, I thank Dr. Firas lbrahim, Dr. Hamid Ghasemi, and their colleagues for a highly informative and productive first meeting. Ananth K. Prasad Chair TRB LTBP Committee Attachment 1: Meeting agenda Attachment 2: Roster of committee members indicating attendance at the meeting of November 28-29,2011 repo¡ts to us for presentation and discussion.