From Hawera the highway follows the coast of the South Taranaki Bight southeastwards to Patea and Whanganui before meeting SH 1 again at Bulls. SH 1 and 3 share their route for 6 km as they cross the Rangitikei River to Sanson, where SH 3 continues southeast towards Palmerston North. After crossing the Manawatu River, the route follows its south bank through the Manawatu Gorge to its terminus and junction with SH 2 at Woodville in the Tararua District