Experimental Study the Impact of Visibility on Individual Ascent Speed in Stair

An experiment was conducted in a 20-level building, where 120 participants were asked to walk upward in the stair in four kinds of visibility conditions (i.e., normal visibility condition, lighting-out condition, the condition of wearing 27% transmittance eye-patch and the condition of wearing 16% transmittance eye-patch). Their upward movement, ascent speeds and behaviors were recorded by cameras. In normal visibility condition, the ascent speeds of males and females decrease continuously for the 1–10 levels, and then the speeds keep at around 0.69 m/s for the males and 0.57 m/s for the females. In lighting-out condition, the ascent speeds of males and females decrease continuously for the 1–12 floors and 1-10 floors respectively, and then keep at around 0.68 m/s for the males and 0.57 m/s for the females. For the two scenarios, participants used the handrail in upward movement process as physical exertion. In condition of wearing 27% transmittance eye-patch, the ascent speeds of males and females maintain at 0.71m/s and 0.51m/s. In condition of wearing 16% transmittance eye-patch, the ascent speeds of males and females maintain at 0.54m/s and 0.48m/s. In the movement process of the two scenarios, participants used handrail to identify the direction of movement. The experimental results showed that individual ascent speed and characteristics of movement are affected by gender, traveling distance and visibility, whilst visibility could be a dominator factor when it is below a certain value.