Following the devastating impact of Typhoon Morakot in 2009, numerous sections of Provincial Highway No. 20 (Southern Cross-Island Highway) sustained severe damage. The Third Maintenance and Construction Office of the Directorate General of Highways promptly launched emergency reconstruction efforts. Initially, temporary riverbed access roads were constructed to restore basic connectivity, with phased openings achieved by the end of the same year. However, due to the inherent difficulties in maintaining riverbed detours and their limitations in serving long-term transportation needs, the office concurrently initiated medium-term bridge upgrades and long-term restoration planning and construction.

In 2012, however, the "610 Flood" brought over 1,500 mm of extreme rainfall, which severely damaged road sections east of Baolai that were still under reconstruction from Morakot. As a result, the reconstruction strategy was revised to include a comprehensive long-term plan covering the entire 206-kilometer alignment of the Southern Cross-Island Highway.

Issued by: Directorate General of Highways, MOTC
Executing Agency: Third Maintenance and Construction Office