The Sixth International Conference on Traffic and Transportation Studies (ICTTS) will be held in LanZhou (China) August 5-7, 2008. The conference will be found to be an excellent forum for researchers, experts and professionals, government officials, policy makers, and managers from around the world to present, discuss and exchange views and experience on recent developments in transportation. It will also provide a variety of opportunities to explore the key issues, innovative technologies, current projects and future prospects for transportation system studies.