RECALL, OR DELAYABLE RECALL

Actuated phases of modern traffic signal controllers are provided with several recall modes. When any recall is ON, it calls that phase to Green or Green-Walk regardless of an actual detector actuation. Conventional recalls operate every cycle, even soft recall when traffic is light. The most common recalls are: (1) Vehicle Recall, (2) Pedestrian Recall, (3) Maximum Recall, and (4) Soft Recall. This article explains recall -- its applications, how recall delay works, advantages of delayed recall, purchasing delayable recall controllers.