In Europe and the United States, for volume transportation measures, high-speed transportation using airplanes and road networks was considered promising, and the opinion was gaining support that railways would be replaced with such new networks and would be old-fashioned.
当時欧米では、将来の大量輸送手段として航空機と高速道路網による高速輸送が有望視され、鉄道はそれらに取って代わられる時代遅れのものだという見解が広まっていた。