Using energy consumption constraints to control the freight transportation structure in China (2021–2030)

China has formulated a series of energy-saving policies to combat climate change, including energy consumption limit to 6 billion tonnes of standard coal by 2030, thus controlling the energy consumption of freight transportation is crucial for achieving energy-saving goals. In this study, the annual control model for freight transportation structure adjustment (FTSA-AC model) was established from the perspectives of the target year prediction and intermediate year controlling to control energy consumption in the freight sector. Innovatively, an efficient algorithm was designed to solve the model and obtain the annual control plan of freight transportation structure adjustment in China (2021–2030). Accordingly, the national freight transportation structure will be continuously adjusted to the optimal state until 2027, and the freight turnover will be achieved at a steady growth rate of 1.50% from 2027 to 2030. The freight turnover will reach 22888.040 billion tonne-kilometres by 2030, in which railways, highways, waterways, and aviation would account for 18.92%, 30.20%, 50.76%, and 0.12%, respectively. According to the results, freight energy consumption will reach its peak in 2029, with 145 million tonnes of standard coal. Lastly, a series of reasonable policy recommendations were presented to provide a reference for energy-efficient freight transport development in China.