What does a 'Pedestrian Crossing' (zebra crossing) sign look like in NSW, and what must a rider do when approaching one?

1. A yellow diamond with a walking-person symbol; only stop if a pedestrian is already more than halfway across
2. A circular blue sign with a walking person; stop only if a pedestrian waves you down
3. A rectangular green sign; slow to 40 km/h but do not need to stop if the crossing is clear
4. A rectangular black-and-white striped sign; give way to any pedestrian on or entering the crossing