National Freeway 3, also known as Formosa Freeway, is a freeway in Taiwan. It is the second north–south freeway in Taiwan, beginning in Keelung City at Jijin Interchange on the provincial highway 2 and ending in Linbian, Pingtung on the provincial highway 17. It is the longest freeway in Taiwan with a total length of 431.5 km (268.1 mi). The freeway is also the only one in Taiwan to have a spur route, Freeway 3A.