Until December 1997, a short section of the highway between Ourimbah and Kangy Angy was used by Sydney–Newcastle Freeway traffic as there was no freeway alternative. This section of the Pacific Highway was designated as part of National Route 1 and subsequently National Highway 1. It was also upgraded to dual carriageway in the early 1970s. Due to the shared freeway and highway traffic, the at-grade interchanges between the freeway and the highway at Ourimbah and Kangy Angy became bottlenecks during peak times. In December 1997, the Ourimbah Creek Road to Kangy Angy stage of the freeway, located 150 m west of the highway, opened to traffic. The new freeway section was one of the last sections of the freeway to be completed and was referred to as the "missing link" of the freeway. The Pacific Highway was bypassed and reduced to one lane per direction, and the northbound carriageway and bridge over Ourimbah Creek north of Palmdale Road were removed. The at-grade interchange between the freeway and the highway at Kangy Angy was also removed.