That's 40% of "ton-miles" - trains disproportionately move heavy, cheap goods (i.e. aggregate, coal), which makes that number potentially misleading. The percentage of freight moved by rail by "value" is closer to 15% (trucking is ~65%).
Why would one want to emphasize value over weight? If I load up a train with extremely expensive metals, jewels, artwork, etc. couldn’t I raise a countries rail by value measurement overnight?
I agree it's good to consider the whole picture, but ton-miles are probably the most important to consider given the increased diesel required to truck heavy loads, correct?
I’m unclear why you’d care about value at all in the context of this discussion. In context weight and volume are the most relevant metrics.