You can never be too safe on the bike. Last Sunday I (Vaidila) was stopped at a red light in Manhattan (at Broadway/Spring) waiting for the green (like a good cyclist). All of a sudden, a yellow cab fails to stop in time and tags me from behind, smashing my wheel.

busted bike wheel

The moral of the story: You might be doing everything right on your bike, but drivers aren't always paying attention. Ride with caution.