Maglev are less efficent than steel wheels at those speeds. Of course proper maintenance would make the subway smoother and help a lot. france has run regular trains almost to almost 575km/h - though if you really want higher speeds maglev is better but nyc couldn't use those speeds on the subway (though other rail should go faster in the city for service reasons)
Yeah, everyone knows you wouldn’t run a nyc subway at 300 mph.
Where do you get maglevs ant low speed are less efficient? They are frictionless. Of course, I don’t even care if they are. You know what they’re more efficient than? Cars!
Building medium-speed and high-speed maglevs are part of the solution to getting people out of cars.
They are building them in China. Let’s see how far they get.
China built almost 30,000 miles of HSR before the US finished any.
Maybe maglevs will turn out to be one of those things that just doesn’t work in America but works everywhere else.