[threedaymonk]

Pedestrian crossings in the UK are rather unusual compared to most other countries in the world, in my experience.

In most places, crossings work on a parallel/perpendicular system: parallel roads and pedestrian crossings are red or green[1] at the same time. This means that cars turning across a pedestrian crossing must give way (yield) to pedestrians.

The UK system, by contrast, isolates the pedestrian phase from traffic phases: when the green man (the WALK indicator) is displayed, no vehicles will approach the pedestrian crossing from any direction. The time between pedestrian crossing opportunities is longer, but there is no contention for the crossing from cars turning into the road.

The article describes the parallel/perpendicular system. In this scenario, a driver will see a parallel WALK light and a (vehicular) green light at the same time. As the pedestrian crossing typically goes red earlier (because people take longer to cross the road than cars take to cross the intersection), a car driver who watches the pedestrian crossing light or countdown timer gains advanced knowledge of the parallel traffic signal.

1. Or white in some places in the US!

[Rapzid]

New Zealand has a mix. All stop, all direction crossings are usually reserved for downtown high pedestrian flow intersections.

There is also a distinction between green and green arrow turns. Green arrow indicates safe turns and green means yield to traffic/pedestrians.