Quote Originally Posted by ny biker View Post
It's superfluous and annoying until it prevents an accident. And it's necessary because of the road noise -- I can't hear many cyclists when they are passing me. And the ones I can't hear are always the ones who are two inches to my left. Which means if I swerve we'll crash and get hurt.

You can't assume everyone will act predictably and safely.
This thread still seems to be more about the safety re: buzzing than calling out. Still, at Hains on a crowded day, if I know I'm going to be swerving for a manhole or walker or roller-skier, I will look back before moving over to check for all kinds of traffic. Cars traveling at the low speeds they are supposed to be going on that loop are frequently as hard to hear as a cyclist in the wind.