BACKGROUND

Federally required state department of transportation (DOT) Transportation Asset Management Plans (TAMPs) must include a process for risk management analysis. State DOTs are tasked with prioritizing bridges for preservation, rehabilitation, and replacement within available budgets. Investment strategies result from evaluating various levels of funding to achieve targets for bridge condition and performance effectiveness at a minimum practicable cost while managing risks. Risks include those associated with performance due to extreme events and bridge conditions. While probabilistic data, methods, and tools exist to quantitatively assess the response of bridges to extreme events using system-wide data (e.g., fragility curves), equivalent approaches for condition-related risks remain underdeveloped. Addressing this gap requires a clearer understanding of the mechanisms and circumstances that lead to unplanned bridge postings and closings due to bridge conditions.

Unplanned postings and closings related to conditions may result from different causes, including (1) discovery of severe deficiency affecting strength or stability, (2) substantial change in condition since the previous inspection or due to accelerated deterioration, and (3) degradation from normal traffic or environmental loading on compromised members. These situations may be more prevalent in certain bridge types and materials (e.g., timber), component or element types (e.g., truss), element defect types (e.g., corrosion, fatigue), site locations (e.g., wet vs. dry), and so forth. Research is needed to develop procedures and tools for state DOTs to quantify the likelihood of unplanned bridge postings and closings as a function of bridge condition and defining attributes.

OBJECTIVE

The objective of this project is to develop procedures and tools for state DOTs to quantify the likelihood of unplanned bridge posting and closing as a function of bridge condition and defining attributes. The research will quantify this likelihood in terms of annual probability values that can be applied to individual bridges.

Accomplishment of the project objective will require at least the following tasks.

TASKS

Task descriptions are intended to provide a framework for conducting the research. The NCHRP is seeking the insights of proposers on how best to achieve the research objective. Proposers are expected to describe research plans that can realistically be accomplished within the constraints of available funds and subaward time. Proposals must present the proposers' current thinking in sufficient detail to demonstrate their understanding of the issues and the soundness of their approach to meeting the research objective.

Note: Proposers shall include the schedule for each phase in their research plans. The sequencing of tasks and deliverables (such as technical memorandums or summary reports) shall be structured for delivery in quarterly progress report submissions. An in-person interim meeting, to be held in Washington, DC, should follow the submission of the first interim report.

PHASE I—Planning

Task 1. Conduct a literature review of research, documents, and case studies on (1) unplanned bridge postings and closings and (2) means of quantifying risks associated with condition and attributes relevant to this research. The review shall include published and unpublished documentation and research conducted by the NCHRP; Federal Highway Administration; and other national, state, and local agencies.

Task 2. Synthesize the results of the literature review to identify knowledge gaps related to the research objective. These gaps should be addressed in the final product or the recommended future research, as budget permits.

Task 3. Propose the research plan to be executed in Phase II to achieve the research objective. At a minimum, the research plan shall include:

• Identification of state DOTs and other bridge owners that can provide data and information on unplanned bridge postings and closings. Data and information collected shall include:
  • Posting load and percent reduction below legal load.  
  • Extent of bridge closure (partial or full closure).
• Analysis of data and information collected. It shall include the identification of estimated annual probability of:
  • Unplanned bridge posting as a function of bridge-level conditions and attributes. Determine if the probabilities can be grouped by percentage reductions below maximum legal loads.
  • Unplanned bridge closure as a function of bridge-level conditions and attributes. Determine if the probabilities can be grouped by partial and full bridge closure.
• Development of procedures and tools (e.g., charts, curves, tables, equations, spreadsheets) that quantify the likelihood of unplanned bridge posting and closing in terms of annual probabilities. It shall include the following considerations:
  • The estimated annual probabilities must vary as a function of bridge condition and attributes. Key attributes may include:
    • Bridge type and material.
    • Elements type and material.
    • Element defect type and quantities.
    • Load rating values compared to legal load.
    • Bridge location and environment.
    • Traffic magnitude.
    • Age.
    • Bridge size and span lengths.
    • Presence of deck joints/span continuity.
    • Maintenance intensity, etc. 
  • The procedures and tools shall be based on readily available or acquired system-level data, such as
    • National bridge inventory (Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation’s Bridges or Specifications for the National Bridge Inventory).
    • State DOT element data, including defect data.
    • Other commonly available data. 
  • The procedures and tools shall be developed for component-level data and for element-level data and shall be applicable to current and projected conditions.
  • Exclude unplanned postings and closings that resulted from natural and manmade hazards that are more appropriate for hazard related risk assessment and management.
• Development of recommendations for enhancing bridge management systems to accommodate analysis using the developed procedures and tools.
• Development of examples/case studies to demonstrate the use of the procedures and tools.

Task 4. Prepare Interim Report No. 1 that documents Tasks 1 through 3, includes the data archiving and sharing plan (see Special Note B), and provides an updated work plan for the remainder of the research. The updated plan must describe the process and rationale for the work proposed for Phases II and III.

Note: Following a 1-month review of Interim Report No. 1 by the NCHRP, the research team will meet with the project panel to discuss the interim report. Work on Phase II of the project will not begin until authorized by the NCHRP.

PHASE II—Execution

Task 5. Execute the research plan according to the approved Interim Report No. 1.

Task 6. Develop the procedures and tools.

Task 7. Prepare Interim Report No. 2 that documents Tasks 5 and 6 and provides an updated work plan for the remainder of the research. The updated work plan must describe the process and rationale for the work proposed for Phase III.

Note: Following a 1-month review of Interim Report No. 2 by the NCHRP, the research team will meet with the project panel to discuss the interim report. Work on Phase III of the project will not begin until authorized by the NCHRP.

PHASE III—Final Products

Task 8. Revise the procedures and tools developed in Phase II after consideration of the panel’s review comments.

Task 9. Submit the final deliverables including (1) the procedures and tools, (2) a conduct of research report that documents the entire research effort and findings, (3) examples, and (4) a stand-alone technical memorandum titled “Implementation of Research Findings and Products.” See Note IV for additional information.

Note: Following receipt of the draft final deliverables, the remaining 3 months shall be for NCHRP review and comment and for research agency preparation of the final deliverables. The budget for Phase III shall be $50,000.

SPECIAL NOTES

A.  The research team should anticipate making two presentations to appropriate technical committees at AASHTO meetings.

B.  To ensure that data produced under this project are accessible, the agency performing the research shall prepare a data archiving and sharing plan to be submitted with Task 4. The plan shall outline how data will be produced, documented, archived in the NCHRP permanent repository, and made publicly available following CRP review and approval.

The plan must address the following elements:

• Data Production and Format: Expected data types, structure, and final formats.
• Documentation and Tools: Supporting materials and any analytic tools or results to be provided.
• Archiving and Quality Assurance: Procedures for data archiving, validation, and quality control.

< < < IMPORTANT > > >

I.   The brochure Information and Instructions for Preparing Proposals for the Transportation Research Board’s Cooperative Research Programs includes extensive guidance on the preparation of proposals for submission to CRP. Revisions to these instructions are highlighted in yellow within that document.

II.  Proposals will be rejected if any of the proposed research team members work for organizations represented on the project panel. The panel roster for this project can be found at https://www.mytrb.org/OnlineDirectory/Committee/Details/7227. Proposers may not contact panel members directly; this roster is provided solely for the purpose of avoiding potential conflicts of interest.

III. The text of the final deliverable is expected to be publication ready when it is submitted. It is strongly recommended that the research team include the expertise of a technical editor as early in the project timeline as possible. See Appendix F of the Procedural Manual for Subawardees Conducting Research in the Transportation Research Board’s Cooperative Research Programs for technical editing standards expected in final deliverables.

IV. The required technical memorandum (no more than 10 pages) titled “Implementation of Research Findings and Products” should address the following implementation frameworks: (1) Effective Products; (2) Implementation Stages; (3) Implementation Drivers; (4) Implementation Teams; and (5) Product Feedback. For more information on the frameworks, read the TR News article “Active Implementation at the National Cooperative Highway Research Program: Frameworks for Moving Research into Practice,” available at https://www.nationalacademies.org/osdocs/NCHRP20-44_ActiveImplementation-TRNews.pdf.

V.  The National Academies have an ethical and legal obligation to provide proper attribution whenever material from other sources is included in their reports, online postings, and other publications and products. TRB will review all Cooperative Research Programs draft final deliverables using the software iThenticate for potential plagiarism. If plagiarized text appears in the draft final deliverable, the research team will be required to make revisions and the opportunity to submit future proposals may be affected.