That's the crux of what's wrong with commuter rail thinking in North America: "Serving the city is what the subway is for". Your original post, asking for 200km

That's the crux of what's wrong with commuter rail thinking in North America: "Serving the city is what the subway is for". Your original post, asking for 200km/h commuter rail, is a sign of it. There's a meaningless separation of modes based on technology, and ascribing attributes to them. In Japan or Europe, the technologies are converging and so are the modes. Any infrastructure will have it's utilization maximized, and may function as what North Americans understand as 'commuter rail', subway' or 'light rail' all at the same time. The result: more coverage, more service, better integration of services, more overall effectiveness, more ridership, less reliance on driving.