What does a flashing amber light at the pelican-crossing mean?

When a pelican crossing (also known as a pedestrian crossing) shows a single flashing amber light, this means that pedestrians should prepare to cross the road but should not cross yet.

However, if there are no vehicles approaching that could turn into the path of pedestrians, they can cross the road. Alternatively, pedestrians may wait until the amber light changes to a green man in order to cross.