AbstractHurricanes Katrina and Rita struck the US Gulf Coast in 2005, leading to the largest mass evacuation in US history and straining the region’s transportation infrastructure and services. This case study addresses the topic of disaster response to transportation unmet needs through an unprecedented spatial and longitudinal analysis of transportation-related disaster 2-1-1 call data collected in real-time, allowing for the investigation of unmet transportation needs by location and disaster phases. The authors analyze 25,205 transportation-related calls logged in Texas’ 25 regional 2-1-1 Area Information Centers from August 1 to December 31, 2005, including a baseline period before Hurricane Katrina, evacuation and landfall, and 3-months recovery post-Hurricane Rita. The spatial results show that transportation unmet needs were concentrated in Texas’ major metropolitan areas, especially in Houston-Galveston, and along highway evacuation routes. However, after controlling for population size, areas close to the landfall site and evacuation destinations had greater unmet transportation needs. Longitudinally, transportation unmet needs surged during evacuation and immediate disaster response then returned to baseline levels during recovery. Based on the results of the case study analyzing Texas 2-1-1 call data of unmet transportation needs, strategies and policies for improving mass evacuation and transportation support services are proposed and discussed.