Originally Posted by Helmet Head
I don't think I ever use the slow signal to indicate I'm slowing down. I use it more like when I tap the brake pedal in my car to cause the brake lights to flash to get a tailgater to back off.
Motorists are often uncertain what to do when they encounter a cyclist up ahead in their lane. Given the unpredictable behavior of many cyclists, they get nervous. A slow signal is a very useful way to quickly and efficiently communicate all of the following:
- I know you're behind me.
- I know what I'm doing.
- I'm not unpredictable.
- At least for the moment, I'm not getting out of your way.
- When it's safe and reasonable to pass me, I'll let you know.
- You don't need to be nervous.
- Back off (if you're too close).
I would be oblivious to the usefulness of the ability of the slow signal to be able to accomplish all that if I did not use a mirror.
I agree with all of this, except the last sentence. Yes, a mirror is helpful, and I use one. But most of the time when I use the slow signal (or almost any signal for that matter), I also turn my head, if only briefly. This makes the driver more likely to notice and heed the signal (and communicates that I'm aware of his/her presence, not just slowing down obliviously), and gives me some feedback on whether my signal was understood. So I imagine I could accomplish almost the same thing without a mirror. The mirror just makes it a bit easier to monitor the traffic behind me.
If my trigonometry is not mistaken, a straight arm at a 45-degree angle will stick out further to the left (albeit lower and perhaps less visibly) than the right-angle, across-and-down signal that HH uses. Plus it strikes me as more appropriate, because it has less of a literal association with the meaning, "I'm slowing down". I most often use it on narrow two-lane city roads with parallel-parked cars on each side, where an impatient driver is behind me and I'm looking for an opportunity to move right (into a long enough gap between parked cars) and allow the driver to pass (rather than incite his anger and let him hassle/tailgate me until the next and possibly unsafe opportunity to pass). So my meaning is, "Hold your horses, I'll let you pass me in a second." Then when I move over, I wave the driver to pass. I may have a right to stay my course and hold him up, but in such cases we'd both prefer him to be in front of me, so I'll do what I can to accomodate that safely and courteously. Plus he probably believes I don't have a right to be there -- thus he believes himself justifiably angry -- and nothing I say is likely to change that belief/attitude. (I used the male pronoun only for convenience; female drivers can be equally impatient and ignorant.)