A standardized color code is used to aid the driver in the prompt
recognition of highway signs. At night, these signs are illuminated by
various light sources including the headlights and other fixed light
sources. These light sources may distort the appearance of the colors
of the signs at night.
The first objective of this study was to provide information about human
capabilities with respect to the recognition of different colors under
daytime and nighttime lighting. The second objective was to examine the
effect of changing the specifications for highway colors from the
Federal Highway Administration (FHWA) standards to the American National
Standards (ANSI) safety color specifications.
A laboratory experiment was conducted in which subjects named the
perceived colors of retroreflective signs viewed under daytime and
nighttime lighting. Forty subjects from four different age groups
representing the driving population participated in the study. Three
color samples (red, orange, and yellow) in three different grades
(engineering grade, high intensity grade, and diamond grade), and two
different color specifications (FHWA and ANSI) were used. Four
different fixed light sources (clear mercury, coated mercury, coated
metal halide, and high pressure sodium) were used for illuminating the
signs. For the nighttime condition, two headlights were used (metal
halide and tungsten halogen). Daytime lighting was simulated using a
fluorescent D-65 light source. Response times as well as correct
responses for naming the colors were collected for each subject.
Significant differences were found for nighttime versus daytime viewing
of the signing materials. In general, for nighttime viewing, red and
orange colors were identified faster than yellow color samples. In most
cases, FHWA colors were identified significantly more accurately and
faster than the ANSI colors. The coated metal halide headlight
performed better than the other fixed light sources. There was no
significant difference found between the tungsten halogen and the metal
halide headlights. / Graduation date: 1991
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/37992 |
| Date | 02 August 1990 |
| Creators | Saremi, Ahmad Reza |
| Contributors | Safford, Robert |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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