From what I've seen in Seoul, "cut and cover" doesn't take a year, but more like five years. And Seoul isn't exactly known for slow construction problems, so I

From what I've seen in Seoul, "cut and cover" doesn't take a year, but more like five years. And Seoul isn't exactly known for slow construction problems, so I think it probably can't be made much faster. It can still be cost effective, but it can be rather unpleasant during the construction period.