Expressways () in South Korea, officially known as National Expressways (), are controlled-access highways that form the highest level of the country's road network. Most sections are tolled and maintained by the Korea Expressway Corporation, though a few routes are built and managed by approved private companies.
On 2 September 1967, the first expressway of South Korea, nowadays Gyeongin Expressway, was assigned as Second-class National Highway 95 SeoulâÂÂIncheon () by the presidential decree. The very first section of expressway was opened on 21 December 1968. At first, expressways were assigned as a part of national highways, but since 31 August 1971, they were assigned as the new separated class: National Expressways.
Under the new numbering scheme implemented on 25 August 2001, expressway numbers were assigned based on a grid system, reflecting the layout proposed in the 3rd Comprehensive National Territorial Planning () in 1992. This updated system was influenced by the numbering conventions of the Interstate Highway System in the United States. The details are:
The current highway shield for expressways is inspired by U.S. highway signage, combining the shape of U.S. Highway shields with the red, white, and blue color scheme of U.S. Interstate shields which are the same colors used in the South Korean flag.
Most of the expressway network is managed by the Korea Expressway Corporation. Since 2000, however, some routes have been constructed and operated by private companies under government approval. These privately operated routes are managed for a limited time before transitioning to public control.
Hi-passÃÂ is anÃÂ electronic toll collectionÃÂ system for theÃÂ expresswaysÃÂ inÃÂ South Korea.
Some interchanges are designed only for cars with hi-pass.
From Sintanjin interchange, Daejeon to Yangjae interchange, Seoul, a pair of central lanes are dedicated as a bus lane on holidays; technically, it is operated as HOV-6 with cars with 9+ passenger capacity. On weekdays, the restriction is narrowed to Anseong interchange, Anseong to Yangjae interchange.
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.