Safety Recommendation H-08-017
Details
Synopsis: About 6:05 p.m. central daylight time on Wednesday, August 1, 2007, the eight-lane, 1,907-foot-long I-35W highway bridge over the Mississippi River in Minneapolis, Minnesota, experienced a catastrophic failure in the main span of the deck truss.1 As a result, 1,000 feet of the deck truss collapsed, with about 456 feet of the main span falling 108 feet into the 15-foot-deep river. A total of 111 vehicles were on the portion of the bridge that collapsed. Of these, 17 were recovered from the water. As a result of the bridge collapse, 13 people died, and 145 people were injured.
Recommendation: TO THE FEDERAL HIGHWAY ADMINISTRATION: Develop and implement, in conjunction with the American Association of State Highway and Transportation Officials, a bridge design quality assurance/quality control program, to be used by the States and other bridge owners, that includes procedures to detect and correct bridge design errors before the design plans are made final; and, at a minimum, provides a means for verifying that the appropriate design calculations have been performed, that the calculations are accurate, and that the specifications for the load-carrying members are adequate with regard to the expected service loads of the structure.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Highway
Location: Minneapolis, MN, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: HWY07MH024
Accident Reports:
Report #: HAR-08-03
Accident Date: 8/1/2007
Issue Date: 11/21/2008
Date Closed: 8/2/2012
Addressee(s) and Addressee Status: FHWA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FHWA
Date: 1/2/2020
Response: From NPRM Response Letter: The National Transportation Safety Board (NTSB) has reviewed the Federal Highway Administration (FHWA) notice of proposed rulemaking (NPRM) titled “National Bridge Inspection Standards (NBIS),” which was published in 84 Federal Register 61494 on November 12, 2019. Through this notice, the FHWA proposes several updates to the NBIS to address Moving Ahead for Progress in the 21st Century Act (MAP-21) requirements; incorporates technological advancements, including the use of unmanned aerial systems; and addresses ambiguities identified since the last update to the regulation in 2009. Additionally, the NPRM addresses the repeal of two outdated regulations: the Highway Bridge Replacement and Rehabilitation Program, and the Discretionary Bridge Candidate Rating Factor. On August 1, 2007, in Minneapolis, Minnesota, the 1,907-foot-long Interstate 35W highway bridge over the Mississippi River collapsed, and about 456 feet of the main span fell 108 feet into the river. The NTSB’s investigation resulted in recommendations addressing multiple safety issues, including those stemming from insufficient quality control procedures on the part of the bridge design firm and concerning the use of technologies for accurately assessing the condition of bridge components where visual inspections may be inadequate. Safety Recommendations H-08-17, -18, and -20 are all classified “Closed—Acceptable Action.” As evidenced by these investigations, the NTSB supports bridge inspections to ensure the safety of the traveling public on the highway system and has issued safety recommendations that have resulted in the creation of the NBIS and improvements to the standards, such as the establishment of fracture-critical and underwater inspections. The key items that the NTSB supports in the proposed regulations are summarized below: • Requiring inspections of bridges on all public roads, on and off federal-aid highways, including tribally and federally owned bridges, as well as of private bridges connected on each end by a public road. • Changing the permissible inspection intervals for bridges, including providing options for more frequent inspections based on certain risk factors. • Establishing documented procedures for timely completion of load ratings. The NPRM proposes that the time allowed for the completion of load ratings not exceed 3 months from when the need for a load rating is identified. Continuing the monitoring of technological advancements to improve the NBIS and updating bridge inspection policies accordingly
From: NTSB
To: FHWA
Date: 8/2/2012
Response: The NTSB notes that the FHWA worked with AASHTO to develop a comprehensive QA/QC program for bridge design. The program guidance document includes (1) definitions of QA/QC in bridge design, (2) requirements for implementing QA/QC procedures, (3) role designations, (4) examples of established state programs, and (5) current QA/QC guidance from AASHTO and other resources. In a September 23, 2011, memorandum, the FHWA notified its Division Offices of the program’s availability and asked Division Bridge Engineers to work with the states to ensure that their QA/QC programs align with the guidance and the NTSB recommendation. This action satisfies the intent of Safety Recommendation H-08-17; accordingly, the recommendation is classified CLOSED—ACCEPTABLE ACTION. Thank you for your cooperation and for your continued efforts to improve highway bridge safety.
From: FHWA
To: NTSB
Date: 10/14/2011
Response: -From Victor M. Mendez, Administrator: In response to recommendation H-08-17, the Federal Highway Administration (FHWA) initiated efforts to prepare guidance to develop and implement a quality control (QC) and quality assurance (QA) program for the design of highway bridges. The guidance on QC/QA in Bridge Design, (attached) includes the following sections: • Definitions of QC/QA in Bridge Design; • Requirements for implementing QC/QA Procedures; and • FHWA's Role. The FHWA worked closely with the American Association of State Highway Transportation Officials (AASHTO) on the development of State/consultant practices and the subsequent guidance. This document has been approved for inclusion in the next update of the AASHTO Guide to Quality in Preconstruction Engineering (2003). Additionally, AASHTO distributed the guidance on QC/QA in Bridge Design to all State bridge engineers on September 5, 2011. On September 23, 2011, FHWA sent a memo to the Division Offices, asking the Division Bridge Engineers to work with the States to make sure their QC/QA programs align with the guidance and the NTSB recommendation. Given the development and distribution of the guidance on QC/QA in Bridge Design with AASHTO, we respectfully request that H-08-17 be classified as "Closed -Acceptable Action."
From: NTSB
To: FHWA
Date: 8/10/2010
Response: The NTSB is pleased that the FHWA has worked with AASHTO's Subcommittee on Bridges and Structures to study current QAlQC practices by bridge owners for detecting and correcting bridge design errors and construction specifications before finalizing plans and specifications and that, based on the study findings, a QAlQC program is scheduled for completion in late 2010. Accordingly, pending completion and implementation of this program, Safety Recommendation H-08-17 is classified OPEN – ACCEPTABLE RESPONSE.
From: FHWA
To: NTSB
Date: 3/23/2009
Response: Letter Mail Controlled 4/6/2009 1:26:07 PM MC# 2090197: - From Jeffrey F. Paniati, Acting Deputy Administrator: The FHWA concurs with this recommendation to work with AASHTO to develop and implement effective quality control and quality assurance (QUQA) procedures to ensure that the design calculations are accurate, drawings are correct, and the specifications properly account for the expected service loads. We are working with AASHTO’s Subcommittee on Bridges and Structures to develop a strategy for addressing this recommendation. The joint intent is to study current QC/QA practices by the States and other bridge owners for detecting and correcting bridge design errors and construction specifications before the plans and specifications are finalized for advertising. Based on the findings of the study, a new national QC/QA program will be developed for adoption by AASHTO and FHWA. The study of current practices and the development of a national QC/QA program are expected to be completed by March 2010. Significant findings will be released through interim reports.
From: FHWA
To: NTSB
Date: 1/6/2009
Response: Letter Mail Controlled 1/30/2009 2:12:58 PM MC# 2090046: - From Thomas J. Madison, Administrator: Thank you very much for your November 21 letter outlining the most probable cause of the collapse of the I-35W Bridge on August 1,2007, in Minneapolis, Minnesota, as well as the coctributing factors. You also discussed three National Transportation Safety Board (NTSB) safety recommendations (H-08- 17 through - 19) to the Federal Highway Administration (FHWA). First, I would like to thank you and your team for performing such a thorough job in the investigation of the collapse and for sharing the interim findings and lessons learned through a series of NTSB advisories and news releases. Based on the interim findings, the FHWA has worked with the State transportation departments and other bridge owners to make sure our highway bridges are safe for the traveling public. The FHWA appreciates the three very fine safety recommendations to FHWA for improving the quality of bridge design (H-08- 17), using appropriate nondestructive evaluation technologies in inspection (H-08-1 8), and enhancing our training courses for bridge inspectors (H-08-19). We have initiated communication with our partners in the American Association of State Highway and Transportation Officials (AASHTO) to address the recommendations to FHWA and the six new NTSB safety recommendations to AASHTO. We are analyzing the final report and recommendations at this time, and will provide a formal response to NTSB with a work plan outlining action items and a schedule for accomplishing them. Thank you again for your letter, and congratulations to the NTSB for a very complete investigation with recommendations for improving the performance of the Nation's highway bridges. If you have any questions or need additional information, please contact Mr. Myint.