Seoul Metropolitan Government revises data ordinance to establish legal basis for collecting crowd density, flow time and foot traffic data

City says crowd management has improved significantly since CCTV-centered response following Itaewon crowd crush

Officials manage crowds at Yeouinaru Station near Yeouido Han River Park during the Seoul International Fireworks Festival 2026 on Sept. 5. (Not directly related to the article.) [Yonhap]
Officials manage crowds at Yeouinaru Station near Yeouido Han River Park during the Seoul International Fireworks Festival 2026 on Sept. 5. (Not directly related to the article.) [Yonhap]

The Seoul Metropolitan Government announced Saturday that it will collect and analyze big data on crowd density, flow time and foot traffic across the city to prevent mass crowd accidents like the 2022 Itaewon crowd crush, and share the information with police, fire departments and other relevant agencies.

The city recently promulgated and began enforcing an amended version of its ordinance on the provision and activation of data use, which now includes a new provision on the collection and use of big data for crowd management.

The amendment was sponsored by People Power Party Seoul Metropolitan Council member Lee Seong-bae of Songpa District 4 and passed at the 339th extraordinary session of the Seoul Metropolitan Council last month. It contains three key provisions: it authorizes the mayor to collect and use big data on crowd density, flow time and foot traffic for efficient crowd management; it allows crowd data to be linked and shared with autonomous districts as well as local police and fire stations; and it enables administrative, technical and fiscal support to ensure the effectiveness of crowd management data projects.

Under the revised ordinance, the city may collect and use big data on crowd density, flow time and foot traffic for crowd management purposes. The collected information may be shared with autonomous districts, police, fire departments and other relevant agencies within the bounds of personal data protection laws.

The ordinance also allows for administrative, technical and fiscal support needed to carry out related projects. The city said the revision was necessary because crowds regularly or temporarily converge on a wide range of locations — including public transit transfer hubs, public rest areas, cultural and tourism sites, and commercial districts — yet there had been insufficient legal grounds to systematically and objectively measure and record foot traffic in those areas.

The city also said it expects the change to reduce administrative and financial waste caused by individual autonomous districts commissioning separate foot-traffic surveys each time they develop specialized streets, assess commercial zones or draw up crowd safety plans.

Seoul's crowd management system underwent a major overhaul following the Itaewon crowd crush of Oct. 29, 2022. Starting the year after the disaster, the city introduced an AI-powered "intelligent people-counting system" that analyzes CCTV footage to automatically measure the number of people per unit area. When crowd levels exceed a set threshold, autonomous districts, the city government, police and fire departments can share situational updates and respond together.

When the system was first built in 2023, the city pursued the installation of 909 detection cameras at 71 locations expected to see high crowd density. The scope was later expanded, and during last year's year-end and New Year's special safety management period, 1,086 crowd-detection cameras were in operation across 91 locations in Seoul's 25 autonomous districts.

The city has also been developing a "crowd density safety map" and a "crowd accident prevention index" to identify areas at risk of overcrowding in advance. The system measures congestion based on telecommunications data and assesses risk by combining factors such as transit card inflow figures, road gradient and CCTV coverage density.

The city said the ordinance revision is significant because it goes beyond monitoring specific congested areas via CCTV and providing real-time population data at key locations — it now establishes a clear legal basis for the city to collect crowd-related data and share it with autonomous districts, police and fire departments.


ikson@heraldcorp.com