Prior to his current position, he was a Principle Transportation Systems Scientist at the National Renewable Energy Laboratory from June 2015 to September 2017. He was the lead research scientist for the Environmental and Emissions Research Facility at the Texas A&M Transportation Institute from April 2014 to May 2015. Dr. Chen received his Ph.D. degree in Civil Engineering, two M.S. degrees in Statistics and Economics, all from University of California Davis.