Highway 3 begins in Hope. From Vancouver, the Trans-Canada Highway (Highway 1) enters Hope from the west as a four-lane freeway; however at Exit 170, Highway 1 exits the freeway and continues north along the Fraser River. The freeway continues east along the Coquihalla River, designated as Highway 3 and Highway 5, for to Exit 177. There, the freeway turns north and continues as the Coquihalla Highway (Highway 5) towards Merritt while Highway 3 takes the exit and continues east through Manning Provincial Park for towards the town of Princeton. Known as the Hope-Princeton Highway, it begins several significant ascents through the Cascade Mountains; first is the steep climb to the Hope Slide, followed later by the remainder of the climb up to Allison Pass at an elevation of . After the summit of Allison Pass, where Highway 3 crosses from the Fraser Valley Regional District into the Regional District of Okanagan-Similkameen, the road descends for along the Similkameen River before beginning another long climb up Sunday Summit (). Soon after Sunday Summit is the descent into Princeton, where it meets Highway 5A.