Low-cost, low energy, programmable and remotely activatable traffic signs,
particularly suitable for roadside, waterside or comparable use, which signs can
display a variety of messages or images, for example warnings and directions, employ
electropolymeric shutter arrays in front of retroreflective materials (32).
The signs employ daylight or other passive illumination external to the sign, such
as vehicle headlights, to yield high contrast images with good visibility. Optional
features include attention-getting effects such as flashing, economical solar power
means and means to detect vehicle approach to initiate the attention-getting display,
e.g. flashing.
