Expressways in South Korea (Hangul: 대한민국의 고속도로; Hanja: 大韓民國의 高速道路; RR: Daehanmingukui gosokdoro), officially called as National expressways (Hangul: 고속국도; Hanja: 高速國道; RR: Gosokgukdo), were originally numbered in order of construction. Since August 24, 2001, they have been numbered in a scheme somewhat similar to that of the Interstate Highway System in the United States; the icons of the South Korean Expressways are notably similar to those in the United States because they are shaped like U.S. Highway shields and colored like Interstate shields with red, white and blue, the colors of the flag of South Korea.
A numbering scheme of expressways in South Korea changed in 2001. Before 2001, roads are numbered as order of its approval (although not exactly same). This list below is the lines by the old scheme. Note that name, origin and terminus of some lines are changed with numbering scheme.
Since June 1, 1972, all motorcycles except police motorcycles are prohibited from driving on expressways in South Korea, regardless of engine displacement. Before 1972, motorcycles with an engine displacement greater than 250 cc were permitted on expressways.
Since March 15, 1992, all motorcycles except police motorcycles have been banned from certain other roads designated for motor vehicles only. These roads are marked by a circular blue sign with a white silhouette of a car.