They are often unfamiliar with the building and they require as many visual cues as possible for orientation. Some say that an extra metre or two of exit sign visibility can sometimes make a large difference for these people - and the people they rescue. Similar findings were reported by P.G. Wood in the United Kingdom. Some people went only short distances through the smoke, but many of them advanced farther than they could see. 3 Knowing that people do navigate through smoke, we have a responsibility to provide evacuation systems that are visible in smoke, wherever feasible.
Exit signs are essential components of evacuation systems.
Our research identifies simple ways for making exit signs more visible in smoke. In smoke, exit signs should be as bright as possible. In our experiments, people performed better with brighter signs. In a follow-up experiment, we measured people's preferences for sign luminance in smoke. In clear air, the same subjects gave very different results.