[thirdsun]

I'd add Garmin's Varia radar as a better (yet more expensive) alternative to a mirror. It's a bike light combined with a radar that will track and display cars coming up behind you on your bike computer (doesn't have to be a Garmin unit since the standard is open to everyone). Many cyclists who tired it (including me) won't ride without one.

[wpietri]

Could you say a bit more about why you like it? I was thinking about getting back into touring and I just recently learned about them. Previously I was using a mirror that attached to my glasses, which seemed adequate. The radar seemed interesting, but I was concerned that it would more be in the "cute toy" category for me.

[thirdsun]

Sorry, just noticed your reply.

A lot of people consider it a cute gadget before they tried it and regard as essential safety tool once they did. It certainly depends on your use case - in busy cities it's useless since you'll be alerted to cars constantly. However in my area I ride on countless long stretches of road with little to moderate traffic. Cars will surprise you on these kind of roads. Sometimes you don't hear or notice them.

With the Varia radar I'm much more aware of my surroundings. I can take up the middle of the road until a car approaches. I won't be surprised by cars I fail to hear due to strong winds or other noise. I know when it's safe to slalom around obstacles on the street. Or when to do a left turn (I'd still look but I'm not sure if the radar ever missed a car - it's very reliable). These days I'd feel almost naked without my radar.

Plus, don't forget that it's also a very good rear light which you can control from your head unit. Don't underestimate the importance of daytime lights in order to be noticed by cars - that is the single most important measure to avoid accidents on a bike.