U.S. Department of Transportation
Federal Highway Administration
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FHWA-PL-08-016
The Federal Highway Administration provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.
The National Bridge Inspection Standards require transportation agencies to use quality control and quality assurance procedures to maintain accuracy and consistency in their bridge inspection programs. The Federal Highway Administration, American Association of State Highway and Transportation Officials, and National Cooperative Highway Research Program sponsored a scanning study to look at European bridge inspection practices related to quality assurance.
The scan team found that European agencies use their bridge inspection programs to insure highway user safety, meet durability and serviceability expectations, and enhance capital investment decisions. They emphasize quality assurance through well-defined inspector qualifications, periodic calibration of inspectors, data collection, and the use of appropriate equipment to evaluate structures.
Team recommendations for U.S. implementation include developing a rational basis for bridge inspection frequency, guidelines for developing quality assurance/quality control procedures, illustrations and reference photos for manuals, and integrated inspection repair approaches.
Form DOT F 1700.7 (8-72)
Reproduction of completed page authorized
The scan team members wish to acknowledge all of the international host transportation agencies and private firms for their significant contributions to the success of this scan. We also thank them for their gracious hospitality, their excellent presentations, and their sharing of their knowledge and experiences with the team. We truly learned much from our interaction with them all.
The team also thanks the Federal Highway Administration Office of International Programs and the American Association of State Highway and Transportation Officials for their leadership, vision, and support of this effort and American Trade Initiatives, Inc. for making this effort happen.
Prepared by the International Scanning Study Team:
The International Technology Scanning Program, sponsored by the Federal Highway Administration (FHWA), the American Association of State Highway and Transportation Officials (AASHTO), and the National Cooperative Highway Research Program (NCHRP), evaluates innovative foreign technologies and practices that could significantly benefit U.S. highway transportation systems. This approach allows advanced technology to be adapted and put into practice much more efficiently without spending scarce research funds to re-create advances already developed by other countries.
FHWA and AASHTO, with recommendations from NCHRP, jointly determine priority topics for teams of U.S. experts to study. Teams in the specific areas being investigated are formed and sent to countries where significant advances and innovations have been made in technology, management practices, organizational structure, program delivery, and financing. Scan teams usually include representatives from FHWA, State departments of transportation, local governments, transportation trade and research groups, the private sector, and academia.
After a scan is completed, team members evaluate findings and develop comprehensive reports, including recommendations for further research and pilot projects to verify the value of adapting innovations for U.S. use. Scan reports, as well as the results of pilot programs and research, are circulated throughout the country to State and local transportation officials and the private sector. Since 1990, about 70 international scans have been organized on topics such as pavements, bridge construction and maintenance, contracting, intermodal transport, organizational management, winter road maintenance, safety, intelligent transportation systems, planning, and policy.
The International Technology Scanning Program has resulted in significant improvements and savings in road program technologies and practices throughout the United States. In some cases, scan studies have facilitated joint research and technology-sharing projects with international counterparts, further conserving resources and advancing the state of the art. Scan studies have also exposed transportation professionals to remarkable advancements and inspired implementation of hundreds of innovations. The result: large savings of research dollars and time, as well as significant improvements in the Nation's transportation system.
Scan reports can be obtained through FHWA free of charge by e-mailing international@fhwa.dot.gov. Scan reports are also available electronically and can be accessed on the FHWA Office of International Programs Web Site at www.international.fhwa.dot.gov.
All Publications are Available on the Internet at www.international.fhwa.dot.gov.
One of the primary goals of the U.S. transportation community is to improve safety on the Nation's roadways. In response to that goal, Federal, State, and local transportation agencies consider the inspection of the country's nearly 600,000 bridges vitally important. These agencies invest significant funds in bridge inspection activities each year. There is high interest in making sure that the quality of the bridge inspection program is maintained at the highest level and that funds are used as effectively as possible.
The National Bridge Inspection Standards (NBIS) were developed to establish standards for a nationwide bridge inspection program. The intent of this program is to monitor and document the condition of bridges and enhance bridge safety. The January 2005 revision of the NBIS specifically requires State and Federal agencies to assure that quality control/quality assurance (QC/QA) procedures are used to maintain a high degree of accuracy and consistency in the bridge inspection program. The Federal government defines quality assurance as the use of sampling and other measures to assure the adequacy of quality control procedures to verify or measure the quality level of the entire bridge inspection and load rating program. It defines quality control as procedures intended to maintain the quality of a bridge inspection and load rating at or above a specified level. In addition, many bridge owners have elected to collect data beyond that required by the NBIS. Better knowledge of QC/QA programs and data types collected abroad should provide meaningful advice to the U.S. transportation community.
The Federal Highway Administration (FHWA) and most bridge owners also have strategic goals on improving the overall condition of bridges and tactical programs aimed at extending service life. These goals are commonly derived from the interpretation of bridge deficiency data identified and documented through the bridge inspection program. In addition, FHWA uses the inspection data as a factor in allocating and distributing Highway Bridge Program funds. Improving the overall quality and determining that the right data are reported through the inspection program will help maintain a high level of safety for the traveling public, ensure effective use of limited funds with an equitable distribution, and assist bridge owners in achieving their safety and mobility goals.
A 10-member team was formed to study European bridge inspection practices, specifically those related to quality assurance. This team consisted of three representatives from FHWA, four representatives from State departments of transportation, a representative from the National Association of County Engineers, a representative from academia, and a structural engineering design consultant who also served as the report facilitator. The scan was sponsored by FHWA, the American Association of State Highway and Transportation Officials (AASHTO), and the National Cooperative Highway Research Program (NCHRP).
The team conducted a series of meetings and site visits with representatives of government agencies and private sector organizations abroad between June 1 and 17, 2007. The team visited Denmark, Finland, France, and Germany and also met with representatives from Norway and Sweden. The countries were selected through a desk scan based on their advanced activities in bridge evaluation, bridge management, and quality assurance.
The results of this scanning study are intended to assist bridge owners and FHWA in refining and continuously improving actions taken to address the provisions of the 2005 NBIS regulation. Although many QC/QA programs exist in the United States, there was significant interest in exploring the most effective bridge inspection systems in other countries. FHWA is also obligated to satisfy the guidelines provided through the Data Quality Act passed by the U.S. Congress in 2001. The data collected through the U.S. bridge inspection program not only enhance bridge safety for the traveling public, but also help form the basis for programming bridge maintenance, repair, rehabilitation, and replacement activities.
Generally speaking, the team found that the European host agencies put a tremendous value on their bridge inspection programs not only to ensure highway user safety, but also to ensure that durability and serviceability expectations are met and to enhance capital investment decisions on the existing bridge inventory. The agencies place major emphasis on providing for quality assurance through well-defined inspector qualifications, periodic calibration of inspectors, data collection processes, and the use of appropriate equipment to evaluate their structures. Most of the agencies had major programs aimed at inspection uniformity, developed a multitiered inspection program, and had procedures for performing damage assessment and programming maintenance and repair through their inspection process.
The scan team identified many bridge inspection practices and technologies related to the topics of interest. The order in which they are presented in this report is for clarity and does not reflect the priority recommended by the team.
Many detailed, heavily illustrated manuals and references were available as tools for bridge inspectors. These included inspection manuals, maintenance guides, repair manuals, and coding and recording data guides. The primary approach in the United States and the European countries the team visited is visually based inspection. The Europeans use visual aids to a greater extent in recording and coding of data, damage assessment, and maintenance and repair. Numerous manuals are available for inspection and maintenance. To focus inspectors and provide more uniform ratings, types of damage with performance indices were quantified with accompanying photographs. These manuals contain many photos and drawings showing damage and corresponding rating levels. Several countries have implemented standards to quantify concrete cracking in inspection reports. European inspectors were observed to have photographs from past inspections on site to use in current inspections. Inspection vehicles in Germany were fully equipped with field equipment, office space, and bridge records to support activities at the inspection site.
All countries visited practiced standardization of inspection reports, forms, terms, and ratings. Noteworthy practices included generating customized bridge inspection forms by bridge management systems, standardizing terms and rating criteria for inspectors, embedding digital photographs in inspection reports, and requiring designers to identify critical areas of a structure to be inspected. In the field, the inspectors include a level of urgency for any required repair in their assessment of damage found. This level of urgency is used to determine annual allocations of funds, program maintenance repairs, and track repair backlogs.
In Germany, inspectors use a computer program in which they select a structural condition from a pulldown menu and allow the program to generate a rating. In Denmark, separate asset management policies, systems, and practices have been established for major structures to allow better decisionmaking for capital investments.
A variety of approaches are taken by European countries to train and certify inspectors. All countries have technical educational requirements for inspectors, and most require those who lead inspectors to have an engineering degree. Many have specialized training requirements for inspectors to ensure the quality of the inspection and the data provided. Specialized training at the program manager level and performance-based testing requirements were believed to be significant
Maintaining a core of in-house staff with expertise in bridge inspection is a high priority for European owners. Experienced staff provides a cadre of personnel to act as trainers and certifiers of new staff and vendors, provide quality assurance reviews of work performed on behalf of the agency, and develop reference materials in support of agency programs.
All of the countries visited had clear definitions of inspection types and several well-defined scopes for their inspections.
A typical finding was that European agencies have developed a technical decisionmaking process for determining inspection frequency. Usually included in this process is the competency of the inspection crew. Host nations visited believed that inspector qualifications and experience requirements provided confidence in allowing inspectors to determine the duration between cycles of inspections, which are typically up to 5 or 6 years but up to 9 years in France. Denmark and France use risk acceptance criteria to help determine inspection type and frequency.
In establishing their programs, the host nations chose inspection intervals based on the amount of detail in their inspections, interim maintenance inspections, and qualifications of their inspectors. However, the host nations allow the inspection frequency of any individual bridge to be shorter (or perhaps longer in the case of France) than the set frequency or maximum frequency to allow for better allocation of human and capital resources. They base the decision on a number of factors typically related to inventory data, such as condition, size, structure type, age, average daily traffic, and complexity.
Finland had a unique approach to insuring quality. The Finnish Road Administration uses 106 bridges and 26 steel culverts as a control sample or set of reference bridges. Baseline data are gathered from these bridges by experienced in-house bridge inspection staff to provide consistency.
Data gathered are used to fulfill a variety of needs, including the following:
During inspections, host nation bridge inspectors use nondestructive testing (NDT) to assist in their condition coding. Several agencies had detailed references outlining the appropriate use of NDT devices and methods, including terms and definitions, defects for which they are applicable and, in Germany, independent evaluations of NDT products by users. Also, the team observed several unique applications of NDT technology, such as the German use of a specially configured ultrasonic shear wave transducer to identify defects.
Several agencies also use bridges to be demolished to evaluate the effectiveness of NDT methods when possible.
Most of the agencies visited include a cause-of-damage investigation by the inspector as part of their bridge inspection procedure. Inspectors are trained to assess damage to a structural element based on structural stability, user safety, and effect on the damaged component's durability and to recommend corrective action to address the damage. Using the inspector's knowledge of structures, coupled with a determination of urgency, an agency can calculate the immediate and short-term programming levels required. All agencies had procedures that would initiate actions based on the severity of the condition found, with or without a higher level of review and approval. In all cases in which critical structural conditions are found, immediate needs are addressed by contact with the individual responsible for the facility, thus ensuring public safety and protection of the facility from additional damage. Several other owners have procedures to initiate maintenance activities at the direction of the inspector.
Maintenance activities were generally tracked by all agencies in their bridge records. This provided better management data on actual bridge conditions and costs associated with a structure.
In Europe, the emphasis is greater on determining the cause of a particular defect in the bridge. This is in contrast to the U.S. approach of characterizing the element or component, which essentially characterizes the effect of the defect. As a result, integration of mitigation strategies is greater (i.e., repair and rehabilitation activities specified by the inspector).
An additional item of interest identified for consideration in the United States was a DVD developed for use in Germany, "Inspection According to German Industrial Standard (DIN) No. 1076." The DVD is intended for viewing by the general public and outlines the reasons for bridge and structure inspection. The DVD not only provides an informative overview of the inspection process, it also appears to be a useful mechanism for maintaining support from its audience for bridge inspection activities.
The general practice of host agencies was not to use dedicated inspectors on bridges, but to rotate inspectors on subsequent inspections. This practice provides a fresh assessment of the bridge's condition, which in turn should provide for a more reliable assessment or at least confirmation of the bridge's true condition.
During bridge inspection site visits, the team observed bridge details incorporated in the design process to facilitate bridge inspections. At the Great Link Bridge in Denmark, elevators allowed easy access to the towers. Inspectors used a monorail inside the tub girder to move through the structure and transport inspection equipment. A permanent traveler was installed for inspecting the structure's exterior. A measuring system integral with the bearing was used to determine bearing displacement. Also, the pier cap at the expansion end was designed to allow access to inspect the posttensioning anchor block and modular joint. In Germany, concrete steps were built along the wing wall to allow for safe traverse of the side slope. These details would also be helpful in performing bridge maintenance activities.
Based on the above findings, the preliminary recommendations of the team are as follows:
The scan team has developed a detailed implementation plan for the recommended initiatives and practices. Included in the plan are a number of technical presentations and papers at national meetings and conferences sponsored by FHWA, AASHTO, and other organizations to disseminate information from the scan. The plan also includes coordination with AASHTO and FHWA to advance these initiatives and practices, including assisting with development of new FHWA and AASHTO standards and guidelines governing quality in bridge inspection. These and other planned activities are discussed in Chapter 3.
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