Scale Economics Drive 65-85% of Freight Transport Efficiency

A comprehensive research study published in Nature demonstrates that economies of scale, not technological progress alone, have been the primary driver of declining freight transport costs and energy intensity over the past three decades. The analysis of intercity freight data spanning 1925 to 2019 across multiple countries and transport modes reveals that 65 to 85 percent of improvements in energy efficiency can be attributed to increased vehicle loads and larger system capacity, with only the remaining 15 to 35 percent attributable to technology advancement. The research identifies inverse relationships between average load carried and both unit costs and energy intensity that remain consistent across all freight modes, geographies, and time periods.

For example, US freight railways achieved a 77 percent reduction in cost per tonne-km and a 95 percent reduction in energy consumption per tonne-km over a century, primarily through increasing average loads more than fivefold. The study reveals that different modes operate within specific competitive ranges determined by their fixed cost structures, with pipelines and railroads benefiting most from scale increases due to high fixed costs relative to variable costs. The findings have significant implications for supply chain professionals and policymakers.

Rather than awaiting breakthrough technologies, substantial further cost and energy reductions are achievable through infrastructure and legal adjustments that enable fuller exploitation of existing scale economies, particularly in surface transport modes like trucking and rail.