Dr. Clifton serves as the interim Associate Vice President for Research at Portland State University, and as a professor in the Department of Civil and Environmental Engineering at Portland State University. She holds an affiliate appointment in the Urban Studies and Planning Program and is a fellow in the Institute for Sustainable Solutions. Her research, teaching and service activities are focused on transportation and how human mobility is shaped by their needs, the built environment, and technology. She is an internationally recognized expert on transport and land use interactions, travel behavior, pedestrian modeling, and equity in transportation policy. She bridges the fields of transportation engineering and planning and is known for qualitative and quantitative methodological approaches.