Experimental study on visibility of exit signs in buildings

Visibility of exit signs in terms of the height of the sign content was studied experimentally in an 18 m internal corridor. Four factors affecting the visibility including graphics, colours, lighting conditions and ages of the observers were investigated. Combinations of designations containing the English and Chinese words EXIT, five directional indicators and two exit symbols in different colours under normal and emergency lighting conditions were presented to 30 observers of different age groups to determine their visibility. The sign heights detected, identified and identified with confidence were measured. Increased height for correct identification was found for an exit sign containing two symbols as compared to a sign containing only one symbol. A green exit sign was reported to be highly visible. It was also reported that at reduced illumination, the sign height for correct identification increased.