I've road ridden for years, and whoever wrote that mountain biking has its own set of fears was right on. Unclipping upon stopping and safely navigating especially in traffic is second nature to me now (it helps not to ride in areas of congested traffic or times of peak commuter/weekend traffic) but unclipping from my mountain bike is a different challenge altogether, because for the most part, you can't unclip early and anticipate when you want release. I have an underlying fear of the bigger critters on the trail too, I see rattlesnakes on a regular basis, and there have been numerous mountain lion sightings in our area. Not to mention riding with pepper spray in the event that I am confronted by the male of the species when out riding the trails alone. I've thought alot about how I would defend myself if threatened by any eventuality. Its a great suggestion to ride with someone both on the road and moreso on the trail, but in my situation, that is hardly ever possible, and if I wait to find someone to ride with, I don't get to go. I've found the best way to overcome your fears is to try to anticipate and prepare for any contingency based upon common sense as well as other's experience, and go out there and face them...can't live your life not doing things because of fear...on the flip side of that idea is the idea that no one should be foolhardy...trolling unprepared or unaware for mountian lions or riding alone without the necessary plan B isn't a good idea either. When I ride alone I carry cell phone, small gps, pepper spray, CO2 cart for quick flat fix, essentials of 1st aid kit, practiced at quick flat fix, be alert to all that is going on around me...