I don't want to install turn signal lights...was just wondering if they existed (have never seen a bicycle with them). I was thinking about it the other day when I was making a left turn. I was also thinking about the usefulness of hand signals, since what I was taught as a youngster and in drivers ed are different from what is published by my city in their cycling guide. I was also wondering how many drivers out there will recognize my hand signal for what it is, even though I think it's pretty obvious, you never know what the driver of the car behind you has going on between their ears, or what they were taught.