Originally Posted by
canklecat
It's because most people naturally go where they look or where their heads are turned. It takes practice and concentration to look one way and continue straight. All racers must practice this, whether runners, cyclists, motorcyclists or drivers.
From my mountain biking days we used to say "Look where you want to go, not at what you want to miss." I still find that advice hard to follow sometimes.
FWIW, I live 2 miles from Missouri's Katy Trail so I ride on it a lot. I've found a tiny little "ting, ting" Incredibell to be about 50% effective with pedestrians. The other 50% are pretty much oblivious to anything.