Provincial Highway 63 () is a limited-access highway, which begins in Taichung at the intersection of Guoguang Road (Provincial Highway No. 3) and Zhongming South Road and ends in Caotun, Nantou on Bixing Road (Provincial Road 14B). It is commonly known as Zhongtou (Taichung-Nantou) Highway.
The total length of the highway is 19.023 km. However, the viaduct actually begins at 1.8 km (on Wuquan South Road).