Even Electric Trains Use Coal: Fixed and Relative Costs, Hidden Factors and Income Inequality in HSR Projects with Reference to Vietnam’s North–South Express Railway

High-Speed Rail is often advertised as a sustainable alternative to air travel, and accordingly numerous initiatives for the construction of new HSR infrastructure are currently being pursued across Southeast Asia and the globe. However, beneath promises of “zero-emissions travel” frequently lie numerous hidden factors—how much steel is needed to build the railway? What energy sources are being used to generate the electricity which drives the train? Moreover, how many passengers are required for the train to be efficient relative to other forms of transport? This paper seeks to examine these questions to uncover what “hidden factors” may be present in HSR, using Vietnam’s proposed North–South Express Railway (NSER) as an example. This study calculates the CO2 emissions likely to be produced by the NSER from the construction steel and the power consumed in operation using publicly available data on the technical standards of the railway and existing data on emissions per energy source, combining this data with market size analyses of the central provinces of the proposed line based on official population and income statistics across a range of scenarios to estimate what level of ridership will be required to outperform an equivalent-length air journey. The research finds that under current projections, the HSR may emit more CO2 per end-to-end journey than a plane, that even in per-capita terms the emissions may be worse depending on the seat fill rate, and that the market size of Vietnam’s central provinces will present significant challenges in ensuring that the railway is efficient enough to outperform the plane in ridership terms. This demonstrates both the outstanding impacts of coal and other fossil fuel use in the energy mix and the potential link between environmental performance and regional inequality which constitute the hidden costs in HSR projects, and the exacerbated risks to the environment posed by inequality.