What Makes Signage Flash?
You might find these definitions helpful.

If you face a sign ordinance that prohibits flashing signs, but doesn’t define flashing, here is some help from the U.S. Federal Highway Administration:

“The light source of a flashing-signal indication shall be flashed continuously at a rate of not less than 50, nor more than 60, times per minute.” [From Manual on Uniform Traffic Control Devices-Millennium Edition, Section 4DII “ Application of Flashing Signal Indications”]

This being the case, if your electronically changeable copy sign changes messages at 1.3 second intervals or more, it is not considered “flashing.”

These additional definitions appear in the glossary section of the U.S. Small Business Administration’s Website: www.sba.gov/starting/signage.

• Variable-Message Sign: A sign that includes provisions for message changes Also known as a changeable-copy panel, changeable-copy sign, time-and-temperature sign, or electronic message center.
• Message Center: An electronically or mechanically variable message sign that enables changes to be made from locations away from the sign.
• Electronic Message Center: A variable-message sign that uses computer-generated messages or other electronic means of changing the copy. These signs include displays using incandescent lamps, LEDs, LCDs, or a flipper mix.
• Time-and-Temperature Display: A variable message sign that displays current time and temperature in a stationary or alternating manner. Some also display simpler messages.
• Flashing Sign: A sign with an intermittent or flashing light source. Generally, the sign’s message is constantly repeated, and the sign is most often used as a primary attention-getting device. Government highway departments frequently use flashing signs to improve highway safety.
• Animated Sign: A sign depicting action, motion, light or color changes through electrical or mechanical means. Although technologically similar to flashing signs, the animated sign emphasizes graphics and artistic display.

Article from SIGNS OF THE TIMES - July 2004
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