Seoul operates on a metropolitan transit system that carries approximately 8 million passengers daily across subway lines, buses, and regional rail connections. The Seoul Metropolitan Subway opened its first line between Seoul Station and Cheongnyangni in 1974 with 7.8 kilometers of track. The network now spans 331.5 kilometers across nine numbered lines operated by Seoul Metro and additional lines run by Korail, AREX, and private operators. Line 2 forms a circular route around central districts with 50.2 kilometers of track serving stations including Gangnam, Samseong, and Hongik University. Line 1 extends beyond Seoul's administrative boundaries to reach Suwon in the south and Uijeongbu in the north, functioning as both metro and commuter rail. The Bundang Line connects southern Gyeonggi Province suburbs to Gangnam and northern Seoul. The Shinbundang Line operates as an express service between Gangnam and Gwanggyo with trains reaching 110 kilometers per hour between stations. Airport Railroad Express (AREX) runs 58 kilometers from Incheon International Airport to Seoul Station with two service types: the express completing the journey in 43 minutes nonstop, and the commuter train stopping at 13 intermediate stations including Hongik University and Gongdeok.
The T-money card system debuted in 2004 as South Korea's first transportation smart card and now processes over 7 million transactions daily across Seoul and most other South Korean cities. Cards cost 2,500 won at convenience stores and subway station kiosks. Base subway fare stands at 1,250 won for adults traveling up to 10 kilometers, increasing by 100 won for each additional 5 kilometers. The same T-money card deducts 1,200 won on buses. Transfers between subway lines carry no additional charge when using T-money. Transfers between subway and bus within 30 minutes receive a discount, with the second trip charged only for distance exceeding the first trip's included range. Cash fares cost 1,350 won for subway and 1,300 won for bus, with no transfer benefits. Monthly passes do not exist in Seoul's fare system. The Tmoney card also functions for payment at convenience stores, taxis displaying the T-money symbol, and vending machines throughout the transit system.
Seoul City Bus system divides routes into four color-coded categories based on function and range. Blue buses (Ganseongbuses) run long distances across the city on major arterial roads, numbered in the 100-series through 700-series based on geographic zones. Green buses (Jisheon) operate shorter routes within districts, feeding passengers to subway stations, with numbers in the 0000-series using four digits. Yellow buses (Sunhwan) form a circular network around downtown and central business districts. Red buses (Gwangyeok) provide express service from outer Gyeonggi Province into Seoul with limited stops, typically traveling 40 to 60 kilometers. Bus stops display route numbers, destinations, and real-time arrival information on LED screens. The Seoul Bus system operates approximately 380 routes with 7,400 buses. Night buses (N-series) run along 72 routes between midnight and 5:00 AM when subway service stops. The Seoul Topis smartphone application tracks real-time bus locations, arrival times, and seat availability on selected routes, drawing data from GPS units installed in every city bus.
Taxis in Seoul operate under three main classifications visible by vehicle color and rooftop signage. Regular taxis display silver, white, or orange paint and charge a base fare of 3,800 won for the first 2 kilometers, then 100 won per 132 meters or 100 won per 31 seconds when traveling below 15 kilometers per hour. Deluxe taxis appear black with a yellow roof sign, offer larger vehicles and drivers who pass additional service training, and charge 6,500 won base fare for 3 kilometers, then 200 won per 164 meters or per 39 seconds at low speeds. International taxis operate with drivers certified in foreign languages—primarily English, Japanese, or Chinese—and use the same fare structure as deluxe taxis but require advance booking through the 1644-2255 call center or mobile application. Large taxis (jumbo taxis) accommodate up to 8 passengers in van-style vehicles and charge deluxe taxi rates. All Seoul taxis accept T-money cards, credit cards, and cash. A late-night surcharge adds 20 percent to metered fares between midnight and 4:00 AM. Taxi stands exist at major subway stations, hotels, and shopping districts. The Kakao T application, launched in 2015, allows users to hail regular or deluxe taxis via smartphone, displaying estimated arrival time and fare.
Seoul Station functions as the primary hub for KTX high-speed rail service to other South Korean cities and conventional rail throughout the peninsula. The station building completed reconstruction in 2004 and handles approximately 100,000 passengers daily across 14 platforms. KTX trains depart Seoul Station for Busan every 10 to 20 minutes during peak hours, covering 417.5 kilometers in 2 hours 15 minutes at speeds reaching 305 kilometers per hour on the Gyeongbu High Speed Railway. Service to Gwangju via the Honam Line takes 1 hour 40 minutes for 294 kilometers. Yongsan Station, located 3 kilometers south of Seoul Station, serves as the terminus for KTX services to Mokpo, Yeosu, and eastern coast destinations via Gangneung. Cheongnyangni Station on Seoul's eastern edge operates ITX-Saemaeul and Mugunghwa-ho conventional trains to Gangwon Province. Gangnam Express Bus Terminal and Seoul Express Bus Terminal (also called Nambu Terminal) handle intercity bus services to destinations throughout South Korea from south of the Han River. Dong Seoul Bus Terminal in Gwangjin District serves routes to Gangwon Province and northeastern regions.
Bicycle infrastructure expanded significantly following Seoul's 2015 announcement of a 10-year cycling promotion plan targeting 10 percent mode share. The Hangang Bike Path runs 40.1 kilometers along both banks of the Han River from Gwangnaru in the east to Gayang in the west, connecting to separate paths extending to the river's source in Gangwon Province. Seoul maintains approximately 920 kilometers of designated bike lanes as of 2023, though many consist of painted lanes on roadways rather than physically separated paths. The Seoul Bike (Ttareungyi) public bicycle sharing system launched in 2015 with 2,000 bikes and expanded to 20,000 bikes at 1,540 stations by 2023. Users register through the Seoul Bike mobile application or at unmanned kiosks at rental stations, paying 1,000 won for one hour or purchasing day passes for 2,000 won. Bikes must be returned to any docking station within the service area covering most districts north and south of the Han River. Rental periods exceeding one hour incur additional charges of 1,000 won per 30 minutes.
Personal vehicles face significant constraints in central Seoul districts through parking limitations and congestion charges. The Namsan Tunnel Congestion Charge, implemented in 1996 and later discontinued, was Asia's first urban road pricing system. Seoul currently operates a Traffic Safety Charging Zone in the city center bounded by the four main gates of the Joseon Dynasty walls, restricting vehicle access during weekday daytime hours except for residents, business vehicles, and permitted users. On-street parking in commercial districts costs 600 to 1,600 won per 10 minutes depending on zone designation, with rates highest in Jung District and Gangnam. Public parking facilities charge approximately 1,500 to 3,000 won for the first hour. Seoul institutes odd-even license plate restrictions on certain high-traffic days, prohibiting vehicles with license plates ending in odd numbers from entering restricted zones on dates ending in even numbers and vice versa. The restrictions apply to portions of roads near Gyeongbokgung Palace, City Hall, and other congested areas primarily during weekday morning and evening peaks.
Walking remains the primary mode for trips under 2 kilometers in Seoul's dense commercial and residential districts. The Seoul Metropolitan Government designated 140 kilometers of Walking Friendly Streets (Chamdoan Gil) with widened sidewalks, reduced vehicle speeds, and improved pedestrian crossings. Gwanghwamun Square, redesigned and reopened in 2009 along a 557-meter section of Sejongno, provides a pedestrian plaza spanning 34 meters wide between remaining vehicle lanes. Cheonggyecheon, an 11-kilometer stream restored from 2003 to 2005 after decades covered by an elevated highway, runs from Gwanghwamun through eastern Seoul with walking paths on both banks. The Seoul Fortress Wall Trail follows the 18.6-kilometer perimeter of the Joseon Dynasty's original city wall across Bukaksan, Inwangsan, Naksan, and Namsan mountains, divided into four sections accessible from multiple subway stations. Traffic signals in Seoul display remaining seconds before light changes on both vehicle and pedestrian signals. Pedestrian scramble intersections operate at major crossings including Gangnam Station intersection and Hongdae intersection, stopping all vehicles to allow diagonal crossing.
Incheon International Airport connects to Seoul through multiple modes, with the fastest being the AREX express train completing the 58-kilometer journey in 43 minutes for 9,500 won from Terminal 1 to Seoul Station. The AREX all-stop service takes 59 minutes and costs 4,750 won, stopping at Digital Media City, Hongik University, and Gongdeok where transfers connect to Seoul subway lines. Airport limousine buses operate approximately 20 routes from Incheon Airport to hotels and districts throughout Seoul, with fares ranging from 10,000 to 16,000 won and travel times of 60 to 90 minutes depending on traffic and destination. The 6001 route serves Gangnam and southeastern Seoul, while 6002 serves Jamsil and eastern districts. KAL Limousine buses offer premium service with fewer stops and reserved seating for approximately 16,000 won. Taxis from Incheon Airport to central Seoul cost 60,000 to 80,000 won via regular taxi or 100,000 to 120,000 won via deluxe taxi depending on destination and traffic, with tolls included in metered fares. Gimpo International Airport, handling primarily domestic flights and some international routes to nearby countries, sits 15 kilometers west of Seoul Station with subway Line 5 and Line 9 providing direct access, as well as AREX service taking 20 minutes to Seoul Station.
Gimpo Airport connects to central Seoul via subway Lines 5 and 9, both reaching the airport terminal in approximately 30 to 40 minutes from City Hall depending on transfer points. Line 5 requires a transfer at Yeouido or Gongdeok to reach central districts, while Line 9 express trains reduce travel time by skipping intermediate stations between major stops. Airport buses from Gimpo to downtown Seoul cost 7,000 to 9,000 won with travel times of 40 to 60 minutes. Taxis from Gimpo to City Hall area cost approximately 25,000 to 35,000 won depending on route and traffic conditions.
Subway operating hours run from approximately 5:30 AM to midnight on weekdays, with first trains departing terminal stations around 5:30 to 5:50 AM and last trains leaving between 11:30 PM and 12:20 AM depending on the line and direction. Weekend schedules typically match weekday timings. Extended service operates on Friday and Saturday nights until approximately 1:00 AM on select lines including Line 2, Line 5, and Line 7. Station platform displays show train arrival times updated in real-time, typically indicating waits of 2 to 6 minutes during peak hours and 4 to 10 minutes during off-peak periods. Rush hours span 7:00 to 9:00 AM and 6:00 to 8:00 PM on weekdays, when trains reach capacity with standing passengers filling available space between seats and doorways.
Platform screen doors installed at all Seoul Metro underground and elevated stations prevent access to tracks except when trains are present and doors align. The system began installation in 2006 following several fatal accidents and completed installation across all lines by 2017. Stations provide accessibility features including elevators or wheelchair lifts at approximately 95 percent of stations as of 2023, though older stations in central areas may require using alternative exits to access street level via elevators. Station layouts often include underground shopping arcades, particularly at major transfer stations like Gangnam, City Hall, and Express Bus Terminal, where retail corridors extend hundreds of meters connecting multiple exits and subway lines. Numbered exit systems organize subway station egress, with major stations having 10 to 15 separate exits leading to different street corners or buildings. Exit numbers appear on maps and transit applications, allowing precise navigation to destinations.