Had a very scary moment yesterday with Autosteer ON going at 70 mph in the left most lane on CA-85 North coming from Cupertino towards Mountain View. This was mid-afternoon with the sun out. It was all going smoothly until the lane markings quickly became a bit worn-out-looking (not horribly so, a la 405 down in LA) and, all of a sudden, the car yanked right (even though there was a wide shoulder to the left with the divider far way) and went into a state of panic beeping away as there was another car in the blind spot to the right. I was able to take over and pull the wheel hard to the left to avoid a collision. I could hear the guy in the car to the right honking away. Thankfully, I had my hands resting just beneath the wheel and was able to react quickly. Wife and son were in the car and, needless to say, wife was terrified enough (as she could see the car real close to the right) to forbid me from doing any more "beta testing and data generation on Tesla's behalf" (as she put it) with Autosteer except on open, inter-city highways. My confidence in Autosteer is a bit shaken too although all my prior experience thus far on the far more congested 101, 92 and 880 during rush hours has been smooth.