The answer was almost certainly generated by an LLM.
I tried asking ChatGPT if Japanese high speed rail has level crossings and it correctly identified the line I used as my counterexample (Yamagata Shinkansen). I think GP is just plainly misinformed in a more boring way.
alt Hacker News
I tried asking ChatGPT if Japanese high speed rail has level crossings and it correctly identified the line I used as my counterexample (Yamagata Shinkansen). I think GP is just plainly misinformed in a more boring way.