How Do Pedestrian Signals Work?
The pedestrian signal provides time for the pedestrians to enter the street on the steady walk signal or walking person symbol, and to finish crossing the street on the flashing don't walk or upraised hand signal. The signal is normally activated by a push button, which causes the traffic signal controller to operate a pre-programmed timed sequence of walk and flashing don't walk indications.
Walk / Don't Walk
Pedestrian signals consist of walk and don't walk signals or the international symbols displaying a person walking for the walk indication, and a hand for the don't walk indication. The walk indication is displayed in white, and the don't walk indication is displayed in Portland orange.
The pedestrian signal sequence begins when the walk indication is illuminated, and this sequence is typically four to seven seconds long. This sequence should be long enough for a pedestrian to leave the curb and begin crossing the street before the clearance interval begins.
Design / Speed
The pedestrian clearance interval consists of the flashing don't walk indication. During this interval the pedestrian is expected to complete their crossing of the street. The pedestrian should not, however, begin crossing the street on the flashing don't walk indication. The pedestrian clearance interval is typically calculated by dividing the street width by an assumed walking speed of four feet per second, unless a special study indicates that a longer time interval is needed for all pedestrian to safely cross the street, i.e. a slower walking speed of 3.5 feet per second is often used for elderly pedestrians. The actual distance used to calculate the clearance interval is usually the distance from the curb on the near side of the street to the center of the last traffic lane on the far side of the street.
The don't walk indication, steadily illuminated, means that a pedestrian is not to enter the street in the direction of the pedestrian signal.