Although preliminary work on rail lines, bridges, and tunnels in southern Japan was started, work on the project stopped in a few years as the nation's economy and infrastructure deteriorated due to World War II.
虽然在日本南部修建铁路线、桥梁和隧道的初始工作已经起步，但由于第二次世界大战使该国经济和基础设施恶化，几年之后该工程便停了下来。