Final answer:
Flashing 'don't walk' or flashing 'raised hand' signals indicate whether it is safe to cross the road or not at pedestrian crossings.
Step-by-step explanation:
Flashing 'don't walk' or flashing 'raised hand' signals are used at pedestrian crossings to indicate whether it is safe to cross the road or not.
When the 'don't walk' signal is flashing, it means that pedestrians should not start crossing the road.
The 'raised hand' signal, when flashing, means that pedestrians who have already started crossing the road should finish crossing, but no new pedestrians should begin crossing.