[1] The highway begins in front of Chiayi HSR station in Taibao City as HSR Avenue, which connects the station with downtown Chiayi City.

The highway continues eastbound as it leaves Chiayi City for Alishan.

The highway then continues eastbound through the Alishan mountains and enters Yushan National Park, before ending at the junction of PH 21 in Tatajia, located near the foot of Yushan, the highest mountain in Taiwan.

Due to environmental concerns, however, most of the segment extending from Tatajia to Hualien was never built.

The only segment that was completed, between Zhuoxi, Hualien and Yuli, was merged into PH 30 as of 2007.