What must exit signs posted above doorways be?

Exit signs posted above doorways must be illuminated to ensure they are easily visible in low-light conditions and can be seen from various angles. This illumination is essential for guiding occupants safely to exits during emergencies, such as power outages or smoke-filled environments, where visibility may be compromised. Illuminated signs typically use a consistent color, often green or red, and are designed to contrast with their background to attract attention quickly.

While brightly colored signs can enhance visibility, illumination is the crucial factor that ensures the sign's functionality, particularly in emergencies. Flashing or digital signs may also attract attention but are not required by code in all situations, making the illumination standard the most practical and critical requirement for exit signage.