Pedestrian signals consist of three distinct phases: WALK, flashing DONT WALK, and steady DONT WALK. The Manual on Uniform Traffic Control Devices allows either the words themselves or symbols to be used to convey these messages (FHWA, 1988). The symbols are the walking person for the WALK phase and the upraised hand for the DONT WALK phases.

    Unfortunately, prior research has shown that pedestrians do not fully understand the meanings associated with the three phases of a pedestrian signal. The phase that is most misunderstood is the flashing DONT WALK. (Robertson, 1977)

    Many pedestrians perceive the start of this phase to be the point at which they should have completed their crossing and be out the street. On the other hand, other pedestrians arrive at the curb during this phase and perceive it to mean that it is ok to begin crossing because the steady DONT WALK phase is not yet displayed. Unfortunately, both of these interpretations are wrong.

    The flashing DONT WALK phase is a clearance interval and is intended to provide pedestrians with the message that they should complete their crossing if they are in the street or not to start crossing if they are not in the street. This lack of understanding results in the need to either better educate pedestrians as to the meaning of the messages or to provide additional information that can be used by pedestrians to make better decisions regarding when to cross the street.

    In many cities, educational placards posted at intersections, as well as the distribution of educational flyers and brochures, have been used as part of campaigns to inform pedestrians of the signal messages. A supplemental approach to education is the provision of additional information at the crossing location. The count-down signal is a device that displays such additional information for pedestrians.

    Another problem for crossing pedestrians appears to be a lack of understanding or awareness that turning vehicles may be crossing their paths during the WALK phase of the pedestrian signal. While the drivers of these vehicles are obligated to yield right-of-way to the pedestrians, they sometimes do not. The result may be a serious conflict or crash.

    Recent research has shown that vehicle-pedestrian conflicts occur less frequently when pedestrians look for turning vehicles (Van Houten and Malenfant, 1995). Thus, reminding pedestrians to look for turning vehicles as they are crossing the intersection is one approach to reducing this type of conflict. A recent effort by Retting et al. (1996) found that signs and markings reminding pedestrians to look for turning vehicles significantly improved the search behavior of pedestrians and reduced the number of conflicts.

    The wide-spread use of signs and markings, however, may not be financially feasible and may result in unnecessary clutter. An alternative would be to incorporate such a reminder within the pedestrian signal head; the animated eyes display is one such device.