>>1626057Its not about speed, its about sound, more specifically the "tunnel boom":
https://www.youtube.com/watch?v=qNmVEPTLDuIBecause Japan uses larger trains and smaller tunnels than Europe, they have to be creative with the train design to decrease noise.
Also those 3 trains
>>1607869 are from different generations, and that
>>1608613 drives at double the speed.