On the 21st, when BTS's full-member comeback show will take place at Gwanghwamun Square, a security system will be activated, with 15,000 people deployed across the area.
Police expect up to 260,000 people to gather from the stage in front of Gwanghwamun to Sungnyemun.
It is larger than the 2002 World Cup street cheering that drew 200,000–250,000 people and the 2014 visit by Pope Francis that drew about 175,000.
To manage crowd safety and respond to terrorism, 72 riot police units (6,759 officers) and 35 detective teams (162 officers), totaling more than 6,700 police officers, will be deployed in the area.
Because most of the "ARMY" who will pack the site are women, a large number of female officers will be mobilized for searches. In addition to the riot police, personnel from local police stations, precincts, and substations across the city have been pulled in.
Seven mobile patrol foreign affairs teams (43 officers) will also be deployed to prevent crimes targeting foreigners and to ensure those manning the entrances can explain procedures in foreign languages.
In addition, more than 8,200 personnel will be assigned for safety management. They include more than 3,400 from the city, district, and fire authorities, and more than 4,800 from the organizer. One hundred two fire trucks will also be deployed.
In total, about 15,000 people will be assigned just for safety management.
Police will also deploy a range of the latest equipment. Because it is an open-city event that anyone can attend, the plan is to minimize blind spots that people might miss.
High-altitude observation vehicles that can overlook crowded areas from above will be mobilized. Each vehicle seats six and can rise to a maximum height of 8.6 meters. The onboard camera supports up to 30x zoom.
The police special operations unit's "anti-drone vehicle" will also be deployed. If any unlicensed drone flies without permission, except for police drones used for on-site documentation, officers plan to fire a "jamming gun" to disrupt its signal.
Triple cordons have been set up at five main roads and 15 side streets using barricades and police bus walls.
For crowd control, police assumed a virtual stadium was set up around Gwanghwamun and established "crowd control lines," allowing spectators to enter and exit only through designated gates.
The virtual stadium is defined as 1.2 kilometers north to south, from across the Woldae at Gwanghwamun past the Admiral Yi Sun-sin statue to City Hall Station, and about 200 meters east to west.
At 31 gates, metal detectors will operate starting at 6 a.m. to block hazardous items from being brought in. Police officers armed with firearms will also be stationed inside the gates.
Police will divide the event area into 15 zones and assign commander-level chiefs from each police station to each zone to establish a system of responsible command.
Outside the crowd control lines, police will use more than 300 handheld scanners to check the belongings of suspicious individuals. People without identification may be asked to undergo resident registration number and fingerprint checks.
Thirty-one nearby buildings will also be restricted. The goal is to block detours through building entrances and rooftop viewing at the source.
However, because the Press Center will host a wedding that day, a full closure is difficult, so guests will undergo additional screening using hand scanners and other tools.
Police are also considering deploying police buses from 3 p.m. to 4 p.m., when the wedding is scheduled, to shuttle guests between Euljiro 3-ga Station and the Korea Press Center.
To guard against potential terrorism, lockers at 17 subway stations in central Seoul will be temporarily closed until 1 a.m. on the 22nd. The stations include Jonggak, City Hall, Jongno 3-ga, Euljiro 1-ga, Anguk, Gyeongbokgung, Gwanghwamun, Seodaemun, Seoul Station, Dongdaemun History & Culture Park, and Myeong-dong.
Fire authorities have also set up an emergency medical system centered on crowded sections.
On-site clinics will be installed at three locations — the King Sejong statue, the Admiral Yi Sun-sin statue, and the Seoul Hall of Urbanism & Architecture — and will operate from 2 p.m. to 11 p.m. HYBE, the management company, also plans to operate 11 separate medical booths.