Interface Design, Visual Comfort, and Safety Perception: An Empirical Study of Spatial Lighting Environments in Subway Systems

The rapid expansion of metro systems has exacerbated lighting-related issues, including uneven illuminance, glare, and blind spots. These issues compromise passenger visual comfort and perceived safety. Previous research has predominantly focused on individual lighting parameters, paying little attention to the combined effects of multiple factors. Perceived safety is a core objective in metro space design and is particularly susceptible to adverse visual environments. This study uses field measurements, virtual environment simulations, and eye tracking experiments to investigate the influence of lighting conditions and interface design (ceiling height and material) on visual comfort and perceived safety. The findings indicate that light-coloured, low-reflectance materials enhance visual guidance, whereas dark, high-reflectance surfaces induce frequent gaze shifts and diminish perceived safety. The optimal environmental benchmark parameters were illuminance levels of 140–270 lux and a correlated color temperature (CCT) of 4428–6250 K. This study also discusses optimizing interface design parameters in different spatial contexts. It also revealed systematic correlations between lighting parameters and spatial geometry, particularly regarding ceiling height. Elevated spaces require increased illuminance and color temperature to compensate for light attenuation, while areas with low ceilings necessitate reduced lighting intensity and warmer color temperatures to mitigate oppressive sensations. This evidence provides a human-centered theoretical foundation for lighting design in underground transport spaces.