fly by pedestrians, it's dangerous to them, and
you. Watch out for people walking their dog's
on long leashes too. Dogs and kids are always famous
for cutting in front of you at the worst times. You
should always expect the worst possible movement from
anything else on the path.
Using a whistle sometimes helps, but most think
it's a train or something. We use our brakes when approaching,
if only to make that high pitched squealing sound when
braking. This seems to get people's attention, and is
better for avoiding collisions. Probably because they
think that someone is barrelling down on them. You move
quicker when you think you're in trouble.