Seats will be removed from some Line No. 4 subway cars from Wednesday as a pilot project to relieve congestion during morning rush hour, Seoul Metro announced Tuesday.

The organization decided to test its new seating plan on Line No. 4 as it often experiences high congestion levels during rush hour. After comprehensive reviews regarding subway car congestion levels and the subway cars' surrounding environment, seats will be removed from the third subway car on Line No. 4 trains.

In November, Seoul Metro announced that it would remove seats in two subway cars per train on Line Nos. 4 and 7. However, through further discussions regarding passenger safety, the organization decided to limit the move.

According to Seoul Metro data, congestion on Line No. 4 peaked at up to 193.4 percent of capacity during the third quarter of 2023, followed by 164.2 percent on Line No. 7 and 148.6 percent on Line No. 2.

Each subway car on Line No. 4 usually holds up to 42 seats. According to Seoul Metro, removing all 42 seats will free up to 12.6 square meters of space and decrease peak congestion levels by 40 percent.

To prevent safety accidents and for passenger convenience, more stanchions, handrails and perch seats have been installed the seatless subway cars.

"After verifying the effectiveness of removing the seats in reducing congestion, Seoul Metro will decide whether to expand the number of subways with seatless cars," a Seoul Metro official told The Korea Herald. "If the project proves to be effective, the organization plans to look into expanding seatless cars to other Line No. 4 subways running at different hours or to other subway lines."