It's essential on narrow shared paths e.g. a canal towpath, when you're approaching a pedestrian from behind in order to avoid startling them when you pass.
Most people walking the canal towpath around here know this, runners in particular will sometimes be give a wave or visual acknowledgement they've heard you without turning around.
Most people walking the canal towpath around here know this, runners in particular will sometimes be give a wave or visual acknowledgement they've heard you without turning around.