When I drive a car I'm constantly checking the mirrors, and this need to know what's going on around me while I move is just as important, if not more so, on the bike. Now that I've had a chance to use it for over a year, I don't like getting on any bike that doesn't have one and I'm amazed that I don't see more cyclists using a mirror.
A mirror tells you what's behind you; duhhh! But here are some specific things it does for me on the bike:
- I can see what's going to pass me, how far back it is, and what it is, without turning my head or taking my eyes off the road in front of me too long.
- I can see cyclists coming up on me in the bike lane so I can pull to the right to let them pass. "By the way, the proper way to pass another cyclist is to say "on your left" as you approach, so they know you're there and will make room or keep a straight line. Unfortunately, most cyclists I observe don't use this simple courtesy/safety measure. I'm going to write a "How to Pass a Cyclist" post to elaborate.
- At night I can look down into the mirror and thereby cause my headlamp to shine back into the oncoming motorist's eyes, which is just another dynamic light I have going to show the oncoming car that I'm there. Hopefully they'll look up from their texting long enough to see that extra light flashing at them.