{"document_url": "https://en.wikipedia.org/wiki/Special_Metropolitan_City_roads_of_Seoul"}
The Seoul Metropolitan City roads (Korean: 서울특별시도; Hanja: 서울特別市道; RR: Seoulteukbyeolsido) are a system of highways spanning the metropolitan area of Seoul. Urban municipalities maintain and designate highway routes. The numbering system of Seoul is different from other systems, as they use an official number and guide number. The official numbering system is used in the legal system only, while the guide numbering system is used for the signage system and widely by citizens.

Classification

There are three types of Seoul Metroplitan City roads: urban expressways (Korean: 도시고속도로), trunk routes (Korean: 주간선도로), and auxiliary routes (Korean: 보조간선도로).

Urban expressways

There are 10 routes; some overlap with other routes.
Other guided routes
Trunk routes
Auxiliary routes

Three-digit routes
2000-3000 series