Measures
Manual observations from video recordings of closed-circuit television (CCTV) were independently conducted from Monday to Friday in each phase by two observers blinded to the intervention status. Therefore, visitors were not aware of being observed. The speed of the video recordings was accelerated two times to reduce observers’ burden, and the resolution was lowered to protect visitors’ privacy. In addition to counting the visitor journey, whether entering the lift, exiting the lift, climbing the stairs, or descending the stairs, observers also took note of the incidence of stair accidents. The two observers statistically significantly agreed in their counts (