Train hopping is still a thing in the US, I suspect because freight trains are slow.
But what about Europe? Even the slow trains are fast. Although I say that only having seen passenger trains. Are there freight trains that are slow enough? What about controls? The article mentions thermal cams being used to spot train hoppers. I might expect Europe’s tendency to push for safety to manifest as rigorous controls.
UPDATE: found this→ https://hitchwiki.org/en/Train_hopping#Europe