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FOREWORD By Staff Transportation Research Board PREFACE Highway administrators, engineers, and researchers often face problems for which in- formation already exists, either in documented form or as undocumented experience and practice. This information may be fragmented, scattered, and unevaluated. As a conse- quence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem. There is information on nearly every subject of concern to highway administrators and engineers. Much of it derives from research or from the work of practitioners faced with problems in their day-to-day work. To provide a systematic means for assembling and evaluating such useful information and to make it available to the entire highway community, the American Association of State Highway and Transportation Officialsâ through the mechanism of the National Cooperative Highway Research Programâ authorized the Transportation Research Board to undertake a continuing study. This study, NCHRP Project 20-5, âSynthesis of Information Related to Highway Problems,â searches out and synthesizes useful knowledge from all available sources and prepares concise, documented reports on specific topics. Reports from this endeavor constitute an NCHRP report series, Synthesis of Highway Practice. The synthesis series reports on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each re- port in the series provides a compendium of the best knowledge available on those measures found to be the most successful in resolving specific problems. This report of the Transportation Research Board presents the results of an investiga- tion of the use of innovative prefabricated elements and systems to limit traffic disrup- tion during the construction, rehabilitation, and replacement of bridges. The study was designed to assess and document the impact of these systems and elements on the system design effort, on-site construction time and cost, closure time, and environmental impact. In addition, the study attempted to identify the most suitable prefabricated systems for bridge construction, rehabilitation, and replacement. The synthesis report also looks at the use of fiber-reinforced polymers and other advanced materials and new technologies that are gaining in popularity, but are still in the experimental stages. A review of new systems currently under evaluation is also presented. Information for this report was derived from a literature review of the state of the practice for prefabricated bridge elements and systems and a survey of transportation agencies in the United States and Canada. A panel of experts in the subject area guided the work of organizing and evaluating the collected data and reviewed the final synthesis report. A consultant was engaged to collect and synthesize the information and to write this report. Both the consultant and the members of the oversight panel are acknowledged on the title page. This synthesis is an immediately useful document that records the practices that were acceptable within the limitations of the knowledge available at the time of its preparation. As progress in research and practice continues, new knowledge will be added to that now at hand.
