Another four bridges on Nantou-Sanjiao Highway (Sanjiao–Huangpu section) opened to traffic on February 11, marking the completion of the entire main line except the Huangshali Grand Bridge.

The 8.69-kilometer section connects the Nansan Interchange on Minzhong Expressway and the Nantou–Huangpu section. The main line features six-lane dual carriageways, with urban sections equipped with four-lane service roads. Infrastructure includes one grand bridge and four medium-sized/small bridges.

Construction targets completion of all auxiliary works (excluding Huangshali Grand Bridge) by end-May, with Huangshali Grand Bridge's closure scheduled for end-June.