抗日战争时期，大片国土沦陷，唯有西南、西北稍安。当时，中外交通线只有 3条，即：中缅交通线、中印空中走廊和川、陕、甘、新大驿道。但由于中缅交通线经常受阻，中印空中走廊运输量有限，西北交通线事实上成为加强与盟国联系的主通道，西北交通再次与中华民族安危相联，成 During the period of the Anti-Japanese War, a large area of ​​land fell to the southwest and the northwest was slightly secure. At that time, there were only three Chinese and foreign traffic lines, namely, the traffic line between China and Myanmar, the Sino-Indian Air Corridor and the post roads of Sichuan, Shaanxi, Gansu and Xinhua. However, as the traffic lines between China and Myanmar are often hindered and the volume of air traffic between China and India is limited, the northwest traffic line has in fact become the main channel for enhancing ties with the allied countries. Once again, northwest traffic is linked to the safety of the Chinese nation.