Against the global climate response and China’s “dual-carbon” goals, energy conservation and emission reduction in transportation are critical. Using the LEAP model integrating demographic and economic factors, this study analyzes energy consumption and carbon emissions under different scenarios. The sector has high carbon emissions (rising in some regions); traditional energy and road transport structures constrain emission reduction, while hydrogen energy helps cut emissions. Across scenarios, trucks and private cars dominate end-use energy demand. With growing green mobility awareness and new energy vehicle promotion, private car energy use falls, making air transport the second-largest consumer; carbon emissions follow energy consumption trends. Scenario differences are notable: baseline energy consumption peaks at 1.307 billion tons of standard coal in 2051, dropping to 1.225 billion tons by 2060; low-carbon peaks at 977 million tons in 2035; carbon–neutral peaks at 863 million tons in 2031. By 2060, energy use in low-carbon and carbon–neutral scenarios is 20.24 and 29.55% lower than baseline, highlighting policy impact. This reveals transportation energy structure evolution and the key role of controlling energy consumption in emission reduction, offering policy and structural optimization insights.