The 70% share of water transport for EU is weird.
Looking into details, they count ocean going ships that pass through territorial waters. This way Portugal looks like having a huge share of maritime traffic, but in fact this also counts Shanghai to UK ships passing through the ocean 50 km away from Lisbon. IMO this is misleading for any practical purpose.
What looks more real is 5:1 share of trucks in EU vs 3:2 share in the US. I would say trucks dominate the EU freight but they are more or less an equal player to rail in the US.
If a container is sent from China to UK by road, it's going to do a certain amount of tonne·km in EU roads. If it's sent by rail, it's going to do a certain amount of tonne·km in EU railways. And if it's sent by ship, it's going to do a certain amount of tonne·km in EU EEZ waters.
And that's basically what you want to account in this statistics.
I'm assuming US' statistics account for China/US and Mexico/Canada traffic in similar manner.
The 70% share of water transport reflects geography.
Shipping from South of Europe to North of Europe is half the distance of shipping via US East and West coast.
Europe has a smaller area with a longer coast line so more of it (and it's people and industry) is relatively close to sea.
Which means containers from China to UK will mostly choose EU waters and not EU railways or EU roads.
Likewise it means intra-EU cargo is more likely to be shipped from Rome to Hamburg than from New York to Los Angeles.
If you focus one one small area like an EU country like Portugal or an US state like New York you're going to get weird values (not just in modal share but also quantities) because they're transit zones for the rest.
