국지도 84호선은 당초 수도권매립지 인근 해안 우회 경로로 계획됐으나 김포시 양촌면 인근에 산업단지 클러스터가 형성되면서 현재의 노선으로 변경됐다.
National Road 84 was originally planned as a coastal bypass route near the Seoul metropolitan area, but was changed to the current route as industrial complex cluster was formed near Yangchon-myeon, Gimpo.