Visual salience and the attentional conspicuity of fluorescent sign materials

Fluorescent sign materials are widely acknowledged to significantly improve sign detection in real world driving environments. However, little is known about the mechanisms or magnitude of the benefits resulting from the use of fluorescent materials in daytime driving environments. The current research examined the effect of fluorescent sign materials on the allocation of attention using a laboratory visual search paradigm. A quantitative index derived from sign luminance normalized to the MacAdam Limit for the sign's chromaticity (Y/Ym) was also evaluated as a predictor of visual search performance.; Search times for target symbols on fluorescent backgrounds were found to be significantly faster than search times for equivalent target symbols on non-fluorescent materials. MacAdam Limit normalized luminance (Y/Y m) was found to be a weak predictor of search performance. Results suggest that fluorescent materials have uniquely salient characteristics that may be the result of multiple photometric and attentional factors.