These proceedings gather selected papers from the 12th International Conference on Green Intelligent Transportation Systems and Safety, held in Beijing, China on November 17-19, 2021. The book contains cutting-edge research on Green Intelligent Mobility Systems, with the goal of achieving "green, intelligent, and safe transportation systems" as the guiding slogan. The contributions offered here can aid in the advancement of green mobility and intelligent transportation technology by increasing interconnectivity, resource sharing, flexibility, and efficiency. Researchers and engineers in the areas of Transportation Technology and Traffic Engineering, Automotive and Mechanical Engineering, Industrial and System Engineering, and Electrical Engineering will all benefit from the books scope.