Climate change and global warming has been increasingly important in the world. China is the world’s largest energy-consuming and CO2-emitting country and so expected to play an important role in implementing sustainable development. This  study develops a new slacks-based measure (SBM) DEA model under variable returns-to-scale and weak disposability to examine the energy and environmental efficiency of transportation sector in China by province and provide optimal reduction targets of energy consumption and  emission for the provinces. The results of the new model show that they are more valid than the ones by existing models as most provinces in China operate their transportation industries at increasing-return-to scale rather than constant-return-to scale. Even though most China’s provinces performed better than previous results, it is suggested that Chinese government should focus on reducing the input wastes and emissions than increasing the value-added of transportation sector. To improve the environmental efficiencies in China, different approaches and measures should be devised by province as each province confronts different circumstances.