Dr Huan Liu is Associate Professor at the Tsinghua University, China. Her research interest is transportation system-related emissions and environmental impacts. She has served as Postdoctoral Fellow at the Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, Riverside; and as researcher at the International Sustainable System Research Center, trained at the Oxford University. Dr Liu has chaired several national projects, including National Nature Science Fund projects; and published more than 50 journal papers. She has written 7 books/book chapters in Chinese and English. She also holds several patents and software copyrights; and has numerous national and international awards to her credit.