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Signs should produce useful visual information to road and sidewalk users without creating undue glare or visual distraction. In order to assist in navigation and wayfinding, signs must be sufficiently conspicuous. For this reason their brightnesses are often higher than the surrounding visual environment. However, if the brightness becomes too high, the sign risks contributing to visual discomfort. Several published recommendations for limiting sign brightness include limits on the maximum illuminance from the sign (in lux). There is evidence, however, that the maximum luminance of a light source can also influence visual comfort. To investigate the potential role of maximum luminance, a pilot study was carried out to assess visual responses to sign panels producing the same illuminance but differing in luminance.
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