I was out on a three hundred mile Sunday ride by myself. As I approached the second ten mile an hour (sign) button hook turn I noticed a teen age girl in a small car ahead of me. I approached the turn slowly, but right after the sharpest part of the turn, the girl slammed on her brakes and stopped for no apparent reason. I dumped as much speed as I could while taking the only non collision path which launched me off the road. There was no shoulder. A steep drop into :wacko:heavy woods with a wall of thorny vines awaited me. I was thrown off the bike, did a flip and got the wind knocked out of me. I felt my back popping like knuckles cracking. A scratch I would find later on top of my helmet, otherwise ok. Today, am very sore and have a big bruise on my left inner thigh close to the knee. The bike rested on on its side somewhat buried in thorny under growth and thankfully soft dirt. The girl who caused me to crash did not stay stopped. She took off. A few people did stop, and with their help, we carefully towed the bike backwards back up onto the pavement. I brushed clumps of dirt off, removed some vines and the bike started right up. I rode it the hundred miles home, with injured pride, and an aching back. I told my wife about it after I walked in the house under my own power. The only damage to the bike is light scratches on the saddle bag, and front cowl on the left side. I will be ok, but right now am pretty sore and eating muscle relaxers and vicodone. I am baffled as to why the girl stopped, or how I could have avoided the accident. This was not high speed at all, but the angle of the shoulder made it more serious than the speed alone. Glad I didn't get far enough off road to encounter a tree. I usually count on cars trying to kill me, but I really didn't see the full stop in the middle of a very tight turn coming. Ouch!