Walk on the Right!

Now I am walking 35 minutes on the shared pedestrian / cycle track in the mornings I am noticing that most people on foot stay on the left hand side. When did that start? I have always walked facing the oncoming traffic, in this case bikes that can come up very fast behind you, rarely ring their bells and pass with millimetres to spare. I wonder if pedestrians do this on roads without footpaths too, and if so how many casualties could have been avoided?
Rant over - graffiti no. 3 with more to come.