well the author complains "the employees per every kilometer of rail" is low... But the author doesn't actually mention '신분당선 (new-bundang line)', which doesn'

well the author complains "the employees per every kilometer of rail" is low... But the author doesn't actually mention '신분당선 (new-bundang line)', which doesn't even have train drivers (automated)... And the main reason line9 being crowded is: it goes through gangnam! of course it's crowded. Lastly, the stations are built to accommodate +2 extra cabinets (6->8), which is the lowest hanging fruit... (even the screen doors installed for those cabinet places) ...so "economically infeasible to add more cabinets" doesn't seem to make sense to me...