Depending on the spectral distribution of the light produced by the various types of sign lights and headlamps, the chromaticity of illuminated signs will shift markedly with light. This study assessed the possible improvement in driver recognition of traffic sign colors to be achieved by changing from the federal highway administration highway colors to the ansi (american national standards institute) safety colors. Sign color appearance under daylight and various nigttime viewing conditions was investigated. Although some lighting color combinations improved correct color recognition when viewing the ansi safety colors, these improvements were marginal and applied only to some of the signing material colors and types. The details ofthe study and its results are described and discussed.
Abstract