Abstract: On August 29, 2005, Hurricane Katrina devastated New Orleans and southeastern Louisiana, leaving hundreds of thousands either displaced or homeless. Nearly four weeks later, Hurricane Rita made landfall in the southwestern portion of the state, further damaging Louisiana's infrastructure and impacting the New Orleans area. In response, LTRC personnel conducted pavement testing on several on-going construction projects that were submerged to determine if contract modifications would be necessary to address damage impact. Damage was found in asphalt and concrete layers, and subgrades were found to be very weak. For one project, LA 46, LTRC had "before and after" data which indicated that the damage incurred was equivalent to three inches of asphalt concrete. As a result, Louisiana Department of Transportation and Development (LaDOTD) contracted with Fugro Consultants, LP, to conduct testing on 238 mi of state highways in new Orleans at 0.1 mi intervals. Fugro conducted falling Weight Deflectometer, Ground Penetrating Radar, and Dynamic Cone Penetrometer testing along with coring selected locations for thickness and damage verification to determine the extent of structural damage to these pavements. Because there was no "before" data, a traditional forensic type analysis could not be undertaken. With the use of global information system (GIS) mapping and the National Oceanographic and Atmospheric Association (NOAA) flood mapping, data points could be identified as either submerged or non-submerged. The non-submerged data were then considered as a control set, and the submerged data were considered as the experimental set. In this manner, the data could be tested using standard analysis of variance techniques to test the hypothesis that the submerged pavements were weaker and therefore damaged as a result of the hurricanes. It is noted that this methodology does not imply that the non-submerged pavements were not damaged also, but provides a relative damage estimate. Once weaker strength parameters were determined, standard pavement design methods were applied to the structural numbers and subgrade modulii to determine an equivalent amount of asphalt concrete for this strength loss. In general, it was found that asphalt pavements had strength loss equivalent to about two inches of new asphalt concrete and that thinner asphalt pavements were weaker than the thicker pavements. Very little relative damage was detected for the portland cement concrete (PCC) pavements. The composite pavements demonstrated no need for additional structure in the pavement layers; however a weaker subgrade for the submerged areas equivalent to nearly one inch of asphalt concrete was identified. Using recent bid prices in New Orleans of $250,000 per mile for a typical rehabilitation scenario (mill four inches/replace four inches of asphalt concrete), an estimated cost for the approximately 200 mi of submerged state highway pavements would be $50 million. There are another 300 mi of federal-aid and 1500 mi of non-federal aid roads that were submerged in the New Orleans area.