TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 359: Bridge Rating Practices and Policies for Overweight Vehicles explores overweight vehicle permit processes. The report includes information on state and provincial bridge rating systems, bridge evaluation practices, and permit policies as they relate to overweight and oversize vehicles. The report is designed to help in the understanding of the reasons for nonuniform permitting practices. The report reviews specifications, software types, treatment of nonstandard configurations, and allowance for in-place dead loads; processes of permit review; and personnel assigned to permit review.
To help assess proposals for further changes in federal truck weight limits, Congress requested this study through Section 158 of the Surface Transportation and Uniform Relocation Assistance Act of 1987. To conduct the study, the National Research Council convened a special Transportation Research Board committee with experts in pavements, bridges, highway safety, freight transportation economics, motor vehicle design, highway administration, motor carrier operations, and enforcement of motor vehicle regulations. The study focused on four issues identified in the study request that involve potential changes to federal weight limits for Interstate highways: (1) Elimination of existing grandfather provisions; (2) Alternative methods for determining gross vehicle weight and axle loadings; (3) Adequacy of the current federal bridge formula; and (4) Treatment of specialized hauling vehicles--garbage trucks, dump trucks, and other trucks with short wheel bases that have difficulty complying with the current federal bridge formula. For each of these issues, the study committee estimated the nationwide effects of changes in federal limits proposed by the trucking industry, highway agencies, and other groups. Projections of heavy-truck miles by type of truck, region of the country, highway functional class, and operating weight were developed for a base case and alternative truck weight regulatory scenarios. These projections were then used to estimate impacts on truck costs, pavements, bridges, and safety.
This synthesis reports bridge inspection practices in the United States and selected foreign countries. The synthesis is a collection of information on formal inspection practices of departments of transportation (DOTs). These are primarily visual inspections and they provide data to bridge registries and databases. For U.S. inspection practices, this synthesis reports on inspection personnel, inspection types, and inspection quality control and quality assurance. Staff titles and functions in inspection programs are reported, together with qualifications and training of personnel, formation of inspection teams, and assignment of teams to bridges. Inspection types are described in terms of their scope, methods, and intervals. Quality control and quality assurance programs are reviewed in terms of the procedures employed, staff involved, quality measurements obtained, and the use of quality findings in DOT inspection programs. Foreign practices are presented in the same organization of inspection personnel, types, and quality programs. Comparisons of U.S. and foreign inspection practices are included. Information was obtained from a questionnaire sent to U.S. state transportation departments, similar questionnaires modified individually for transportation agencies in selected foreign countries, and formal documents used by transportation departments and agencies. These documents primarily included bridge inspection manuals, inspection training manuals, and technical memoranda, but also included blank forms for inspections, DOTs job descriptions for inspectors, and descriptions of inspection training courses. Overall, this synthesis includes information from forty U.S. state transportation departments and from roads agencies in eight foreign nations (Denmark, France, Finland, Germany, Norway, South Africa, Sweden, and the United Kingdom). The synthesis also includes, in an appendix, information from a few provincial and municipal transport agencies in Canada.
Provides the results of an audit of the Fed. Hwy. Admin. (FHWA) to improve its oversight of states¿ bridge inspections, load ratings, and max. weight postings. FHWA should encourage states to use more detailed data to manage their bridge programs. Shortly after the I-35W bridge collapse in Minneapolis, MN on Aug. 1, 2007, killing 13 people, the Sec. of Transportation asked whether FHWA¿s Nat. Bridge Inspection Program delivered the highest level of bridge safety. Objectives for this audit were to evaluate FHWA¿s: (1) implementation of data-driven, risk-based oversight to target bridge safety risks most in need of attention, particularly those related to load ratings and postings; and (2) promotion of state use of bridge management systems. Table.
First Published in 1999: The Bridge Engineering Handbook is a unique, comprehensive, and state-of-the-art reference work and resource book covering the major areas of bridge engineering with the theme "bridge to the 21st century." This third volume includes sections covering construction and maintenance, special topics, and worldwide practice.
