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Table 7. Number of New Messages Seen at Various Driver Speeds and
<br />Time Intervals Between Messages
<br />*Assuming the sign is clearly visible from one -half mile away.
<br />Prohibiting displays from changing quickly can minimize potential driver distraction, but it
<br />would significantly limit the message owner's ability to convey information that does not fit on
<br />one screen of the sign. Using two or more successive screens to convey a message is referred to
<br />as sequencing. Based on the studies summarized in part 3 of this Report, including the glance
<br />duration studies performed by Klaur for the FHWA in 2006 and by Beijer & Smiley in 2004, and
<br />Wachtel's analysis for Seattle of the Zeigarnik effect, a message delivery system such as
<br />sequencing that requires or induces a driver to watch the sign for several seconds increases the
<br />likelihood of driver distraction. Based on information from the sign industry, for sequencing to
<br />be effective in a marketing sense, a brief rate -of -change (1 -2 seconds) is generally used before
<br />transitioning into the next screen.
<br />Some codes specify how an image changes, while other codes prohibit the use of transitions.
<br />The change from one image to another can be accomplished by various techniques: no transition
<br />— simply a change from one screen to another, or fading or dissolving one image into the next.
<br />Flashing, spinning, revolving, or other more distracting transition methods can be prohibited,
<br />allowing businesses to use sequencing in an effective manner without making the signs overly
<br />distracting. Another way of regulating distracting transitions is to require a very short time of a
<br />dark or empty screen between images.
<br />4.2.4 Motion, Animation, or Video Limitations on Electronic Signs
<br />Motion on a sign can consist of everything from special text effects (spinning, revolving,
<br />shaking, flashing, etc.) to simple graphics, such as balloons or bubbles rising across the screen, to
<br />more realistic moving images that have the appearance of a television screen. According to sign
<br />industry representatives, video imagery on a sign is referred to as "animation" if the sign is
<br />limited to the capability of 10 frames per second. Fewer frames per second make the moving
<br />image look more like animation. Imagery produced by signs that have the capability of
<br />processing up to 30 frames per second is accurately referred to as "video" imaging
<br />Many communities that allow dynamic signs do not allow the application of any type of motion,
<br />animation, or video on the signs. However, Seattle was obliged to allow video imagery on their
<br />signs after earlier signage code regulating certain types of signs was not strictly enforced. In
<br />addition to requiring a dark period between successive messages to overcome the Zeigarnik
<br />effect, Seattle also limits the duration of the video message to a minimum of two seconds and a
<br />21
<br />Number of Messages Seen
<br />Speed
<br />Time sign is
<br />clearly visible*
<br />Message Display Time (seconds)
<br />1800
<br />3600
<br />(mph)
<br />(seconds)
<br />6
<br />8
<br />10
<br />60
<br />(30 minutes)
<br />(1 hour)
<br />30
<br />60
<br />11
<br />9
<br />7
<br />2
<br />1
<br />1
<br />45
<br />40
<br />8
<br />6
<br />5
<br />2
<br />1
<br />1
<br />55 33
<br />7
<br />5
<br />4
<br />2
<br />1
<br />1
<br />Table 7. Number of New Messages Seen at Various Driver Speeds and
<br />Time Intervals Between Messages
<br />*Assuming the sign is clearly visible from one -half mile away.
<br />Prohibiting displays from changing quickly can minimize potential driver distraction, but it
<br />would significantly limit the message owner's ability to convey information that does not fit on
<br />one screen of the sign. Using two or more successive screens to convey a message is referred to
<br />as sequencing. Based on the studies summarized in part 3 of this Report, including the glance
<br />duration studies performed by Klaur for the FHWA in 2006 and by Beijer & Smiley in 2004, and
<br />Wachtel's analysis for Seattle of the Zeigarnik effect, a message delivery system such as
<br />sequencing that requires or induces a driver to watch the sign for several seconds increases the
<br />likelihood of driver distraction. Based on information from the sign industry, for sequencing to
<br />be effective in a marketing sense, a brief rate -of -change (1 -2 seconds) is generally used before
<br />transitioning into the next screen.
<br />Some codes specify how an image changes, while other codes prohibit the use of transitions.
<br />The change from one image to another can be accomplished by various techniques: no transition
<br />— simply a change from one screen to another, or fading or dissolving one image into the next.
<br />Flashing, spinning, revolving, or other more distracting transition methods can be prohibited,
<br />allowing businesses to use sequencing in an effective manner without making the signs overly
<br />distracting. Another way of regulating distracting transitions is to require a very short time of a
<br />dark or empty screen between images.
<br />4.2.4 Motion, Animation, or Video Limitations on Electronic Signs
<br />Motion on a sign can consist of everything from special text effects (spinning, revolving,
<br />shaking, flashing, etc.) to simple graphics, such as balloons or bubbles rising across the screen, to
<br />more realistic moving images that have the appearance of a television screen. According to sign
<br />industry representatives, video imagery on a sign is referred to as "animation" if the sign is
<br />limited to the capability of 10 frames per second. Fewer frames per second make the moving
<br />image look more like animation. Imagery produced by signs that have the capability of
<br />processing up to 30 frames per second is accurately referred to as "video" imaging
<br />Many communities that allow dynamic signs do not allow the application of any type of motion,
<br />animation, or video on the signs. However, Seattle was obliged to allow video imagery on their
<br />signs after earlier signage code regulating certain types of signs was not strictly enforced. In
<br />addition to requiring a dark period between successive messages to overcome the Zeigarnik
<br />effect, Seattle also limits the duration of the video message to a minimum of two seconds and a
<br />21
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