I prefer to think I am more cautious, not fearful! With me, it comes directly from having done this long enough to see what can happen when cyclists are careless, and also what can happen through absolutely no fault of their own. Having been involved in a crash due to some poor cycling habits of others and ending up with a broken bone, I know how quickly an accident can happen and how long it can take to recover from it. As a result, I no longer participate in charity rides where I have to start out with hundreds of other riders all bunched up together (and then remain bunched up until the first rest stop). I still participate in smaller charity rides and just stay out of any packs of riders. Sure, it is fear of another crash, but it is also common sense on practical ways to avoid a crash. There are enough rides out there that I don't feel like I have deprived myself of anything, I have just made a choice to support smaller rides. I think caution -and wisdom- come with age. The only answer I know of is to take the precautions you realistically can and still do the activities you enjoy. Not always an easy balance to achieve. I'm interested in hearing from others.
Grits
2010 Trek 5.2 Madone WSD, SI Diva Gel Flow
2002 Terry Classic, Terry Liberator