Nondestructive evaluation (NDE) methods can be used to assess in-service steel bridges for problematic conditions caused by factors such as design, manufacturing, fabrication, and the service effects of traffic and corrosion. This report discusses typical NDE test methods used on bridges, including penetrant testing, magnetic particle testing, eddy current testing, ultrasonic testing (including phased array testing), radiography, and acoustic emission testing. NDE operations such as flaw location, characterization, and sizing are covered as well. Results of a national survey of departments of transportation’s (DOTs) use of NDE are presented. A simple procedure for using NDE to address DOT bridge concerns is proposed along with a risk-based inspection approach to scheduling/scoping bridge inspections.

Report Date


Report Number


Digital Object Identifier



© 2017 University of Kentucky, Kentucky Transportation Center

Information may not be used, reproduced, or republished without KTC’s written consent.

The contents of this report reflect the views of the authors, who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the University of Kentucky, the Kentucky Transportation Center, the Kentucky Transportation Cabinet, the United States Department of Transportation, or the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names or trade names is for identification purposes and should not be considered an endorsement.