The Effects of Ambient Illumination, Color Combination, Sign Height, and Observation Angle on the Legibility of Wayfinding Signs in Metro Stations

TLDR

Well‑designed wayfinding signs improve metro service, enhance passenger safety during evacuation, and support sustainable public transport. The study examined how ambient illumination, color combination, sign height, and observation angle affect legibility of metro wayfinding signs. Simulated metro‑wayfinding signs were tested for legibility under two illumination levels (70 lux and 273 lux), two color combinations (achromatic‑white on black and chromatic‑yellow on black), two heights (1.5 m and 2 m), and three observation angles (0°, 45°, 70°). Results showed that higher illumination and achromatic color combinations improved legibility, observation angle significantly affected legibility, sign height had no direct effect, and the visibility catchment area was elliptical with a short axis matching the legibility distance at 0°, informing optimal sign placement in metro stations.

Abstract

Well-designed wayfinding signs play an important role in improving the service level of metro stations, ensuring the safety of passengers in evacuation, and promoting the sustainable development of public transport. This study explored the effects of ambient illumination, color combination, sign height, and observation angle on wayfinding signs’ legibility in metro stations. In the experiment, simulated metro-wayfinding signs were made to test legibility. As designed, the legibility was measured based on the following independent variables: two levels of ambient illumination (70 lux and 273 lux), two target/background color combinations (achromatic-white target on black background, chromatic-yellow target on black background), two sign heights (1.5 m and 2 m), and three observation angles (0°, 45°, 70°). The results showed that brighter ambient illumination provided passengers with higher legibility. Achromatic color combination was more legible than chromatic color combination, but not significantly. Different types of signs, set at different height, did not directly affect legibility. Observation angle had significant effects on legibility. Visibility catchment area of wayfinding signs was like an ellipse, with its short axis nearly equal to the legibility distance of the sign at 0 degrees. The findings will facilitate the layout and setting location of wayfinding signs in metro stations and improve the level of wayfinding service.