That’s not most trains. Those are highly specialized and constrained applications. There are already self-driving taxis in certain defined city areas, so they’re still ahead by that standard.
I was in Barcelona last month and the metro was automated. Some trams in Switzerland too when I was there two months ago
I’m not a city person but I assumed that was just normal now.
Dunno if you’re from NA but if so just remember you might be a decade behind on public transport