1. Official Subway Apps (Car & Station Congestion)

Seoul Subway - Official App (또타지하철)

Developed by Seoul Metro, this is the primary app for tracking real-time conditions on subway lines 1 through 8.

• Crowd Tracking: Displays car-by-car congestion levels (Relaxed, Normal, Caution, Congested) so you know which train car has the fewest people before boarding.

• Station Facilities: Tracks real-time train locations, exit congestion, and wheelchair/elevator availability.

KakaoMetro & Naver Map

The standard navigation apps in South Korea both integrate real-time congestion data provided by transit authorities.

• Feature: When you search a route, the apps color-code individual train cars and station arrival platforms based on how crowded they currently are.

2. Citywide Foot-Traffic & Spot Tracking

Seoul Real-Time Congestion (서울 실시간 혼잡도)

If you want to track overall human density inside and around major subway hubs (like Gangnam Station, Hongdae, or Yeouido) or public spots (like Hangang Parks):

• Coverage: Uses Seoul Metropolitan Government public data to track real-time floating population across 120+ major transit hubs, tourist zones, and parks.

• Data Provided: Shows population density stages (Spacious, Normal, Slightly Crowded, Crowded, Very Crowded), demographic breakdowns (age/gender), and forecasted crowd trends.

3. How the Tracking Works (Behind the Scenes)

Seoul's crowd-tracking system relies on three main technologies:

1. Wi-Fi Signal Density: Routers installed in subway cars and stations measure the density of active smartphone Wi-Fi signals in real time.

2. Weight Sensors: Sensors on the subway car undercarriages calculate passenger weight to determine car congestion.

3. AI CCTV Analytics: Major exchange stations (like Itaewon, Hongdae, and Gangnam) use AI-powered CCTV cameras that automatically estimate crowd density per square meter to prevent overcrowding emergencies.