Concern about bridge-foundation scour intensified as highway agencies performed scour evaluations and discovered the inadequacies of current practices. This concern existed in spite of many years of research both in hydraulic scour-prediction methodology and in design of highway crossings to mitigate scour problems. Most research had focused on local vertical scour and other site-specific components of scour. Experience showed the need for refinement of scour-prediction methods and on fluvial system instability.

A strategy was needed to identify and guide bridge-scour-related research. In developing this strategy, it was necessary to (1) assess the validity and applicability of past and present research related to bridge scour and fluvial system instability; (2) define the state of practice; (3) identify gaps, deficiencies, and potential improvements in current scour technology; and (4) make recommendations for future research. Such a strategic research program, covering both fundamental and applied research, would be of value not only to the sponsors of the National Cooperative Highway Research Program (NCHRP), but to other sponsors of bridge-scour-related research.

The University of Louisville developed a comprehensive and balanced strategic plan for research on bridge scour and fluvial system instability that affect highway-crossing integrity. The plan focused on (1) risk and reliability assessment, (2) scour prediction, (3) scour monitoring, (4) inspection, (5) evaluation, (6) conventional and nonconventional countermeasures, and (7) channel-modification processes. The final report included a plan for both serial and concurrent research necessary to meet the most important needs related to bridge scour. It contained a research problem statement addressing each research need and described the expected direct and indirect applications of the research as well as the estimated time and costs, linkages, and sequencing. The recommended plan was the subject to a comprehensive review by the NCHRP, as well as by leading experts convened at a workshop specifically for that purpose. The final plan reflected the workshop review comments. The report will not be published by TRB. However, a draft copy of the report is available at https://vortex.spd.louisville.edu/BridgeScour/ or from NCHRP.