Memorandum
U.S. Department of Transportation
Federal Highway Administration

Since the initiation of the National Bridge Scour Evaluation Program in 1988, the Office of Bridge Technology has been disseminating guidance to State departments of transportation (DOTs) on the conduct of scour evaluations for bridges over waterways. The State DOTs have embraced this program by conducting scour evaluations and reporting their progress to the Federal Highway Administration (FHWA) on a biannual basis. We are delighted to report that State DOTs have reached the milestone of 93 percent completion of bridges needing a scour evaluation as of April 15, 2003. What makes this milestone even more significant is the fact that 42 State DOTs have reached at least 90 percent completion and 16 of these have completed more than 99 percent of their evaluations. We believe that this milestone has been reached, thanks to the strong commitment to safety between the FHWA and the State DOTs and we commend our Division Offices and State DOTs for that. Also, we believe that this national program has significantly helped State DOTs gather the information needed to determine the scour condition of our Nation's highway bridges so that decisions can be made regarding repair, replacement or monitoring of a bridge that has been adversely affected by scour. A summary of the national scour database as reported by State DOTs is shown in the attached table titled "Total Highway Bridges as of 04/15/03" for your information. This database is available in electronic format at http://www.fhwa.dot.gov/engineering/hydraulics/policymemo/scour.htm.

We would like to encourage the FHWA Division Administrators with the remaining 10 State DOTs (AL, CA, FL, GA, MI, MT, NE, OH, PA and VT) to continue working together with the appropriate State DOT management officials towards reaching 90 percent completion of their scour evaluations. These State DOTs should continue reporting their progress to HIBT-20 on a biannual basis. State DOTs with more than 90 percent, but not complete, yet should report to HIBT-20 on a yearly basis. Please remember that the overall goal of the National Bridge Scour Evaluation Program is to complete the scour evaluations of all bridges over waterways in order to determine whether a bridge is low risk to scour or scour critical. If the bridge is found to be low risk, it should continue to be inspected during its regular inspection cycle. However, if the bridge is found to be scour critical, a plan of action should be developed and implemented to address the deficiencies that made the bridge foundation unstable for the observed or calculated scour condition coded in Item 113 of the Coding Guide for the safety of the public users.

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