Today I was stopped behind a gray Altima which was stopped behind a yellow school bus. AP graphic showed 2 cars in front of me. I engaged Autosteer to hold position until the traffic started moving. My car started creeping forward and the dash graphic turned to a single truck icon in front of me. It continued to creep forward very slowly and it was clear that it no longer saw the gray Altima, having moved past the spot that TACC/autosteer would usually stop behind a car. What's interesting to me is that it did not lurch forward as others have mentioned before. It was a very hesitant, slow creep forward, almost as if the camera and radar were disagreeing on what was in front and it was cautiously moving forward. If I had let it continue and hit the car, I doubt there would have been any damage.