Assessment of the impact of color contrast in the detection and recognition of objects in a road environment: final report

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National Surface Transportation Safety Center for Excellence


With the development of new light sources, options for the color and spectral output of a luminaire are wider than for traditional light sources. This can impact visibility as the spectral output of a light source may have a significant impact on the appearance of objects in the roadway environment. This study compares the visibility and color contrast afforded by three separate roadway luminaire types, each with a different spectral output. The benefit provided by the additional color information provided by the spectral distribution of a luminaire can improve detection of objects in the roadway by as much as 50%. These results, however, are not consistent across all spectral output and object color combinations. These results also indicate that the proper selection of a luminaire output will provide better visibility for the driver. -- Report website.