Proceedings of 2009 GeoHunan International Conference, Challenges and Recent Advances in Pavement Technologies and Transportation Geotechnics, held in Changsha, Hunan, China, August 3-6, 2009. Hosted by Changsha University of Science and Technology, China. Sponsored by Geo-Institute of ASCE, USA; Asphalt Institute, USA; Central South University, China; Chinese Society of Pavement Engineering, Taiwan; Chongqing Jiaotong University, China; Deep Foundation Institute, USA; Federal Highway Administration, USA; Hunan University, China; International Society for Asphalt Pavements, USA; Jiangsu Transportation Research Institute, China; Korean Institute of Construction Technology, Korea; Korean Society of Road Engineers, Korea; Texas Department of Transportation, USA; Texas Transportation Institute, USA; and Transportation Research Board, USA. This Geotechnical Special Publications contains 27 peer-reviewed papers that showcase recent developments and advancements in geotechnical and pavement engineering and that offer insights into future directions for geoengineering in the 21st century. Topics include: advances in unsaturated soil, seepage, and environmental geotechnics; geosynthetics; geo-environmental engineering; nondestructive testing of infrastructure materials; and bridge approach embankments.