Portland Orange is the color of light emitted by the phase of
pedestrian crossing signals in the United States and Canada. The color was chosen to avoid confusion with regular
traffic light
Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at intersection (road), road intersections, pedestrian crossings, and other locations in order to control flows of traf ...
s in conditions of poor visibility.
Its
chromaticity
Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called ...
is specified by the
Institute of Transportation Engineers in that body's technical standards,
along with
lunar white for the lights.
Its application is stipulated in the U.S. federal ''
Manual on Uniform Traffic Control Devices
The ''Manual on Uniform Traffic Control Devices for Streets and Highways'' (usually referred to as the ''Manual on Uniform Traffic Control Devices'', abbreviated MUTCD) is a document issued by the Federal Highway Administration (FHWA) of the Unit ...
''. Various jurisdictional standards also require Portland Orange for signs.
The color can be created with some
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
s, and the ITE specifies the precision of its
wavelength
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...
to 3
nanometer
330px, Different lengths as in respect to the molecular scale.
The nanometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American and British English spelling differences#-re ...
s.
[ In practice, the most brilliant color of gaseous tubing is similar to Portland Orange.]
International application
Portland Orange is generally not used outside the United States and Canada. In most of the world, red
Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...
, or another specified color, is used for the symbol instead of Portland Orange.[
]
References
Pedestrian crossing components
Standards of the United States
Standards of Canada
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