In the past, surface communications between northern and eastern Taiwan were more or less limited to the Suao-Hualien Highway, a one-way road traversing rugged mountains which is both dangerous and easily disrupted by landslides during typhoons or other periods of heavy rain.
過去多年來，台灣東北部的對外交通主要靠蘇花公路，但是蘇花公路是單行道，又盤旋在群山峻嶺之上，安全性較低，每逢颱風、豪雨，交通常因坍方而中斷，所能發揮的功能有限。