I was driving in a car; I believe it belonged to someone else. I was going uphill in a street race with several other cars which were all tightly bunched together.  The streets were narrow and windy, and it was snowy.  It seemed nearly impossible to make a pass, even though it felt like the car had good performance, like a BMW.  My car’s performance was better than competitive, but there was just nowhere to go to get through the field, to move up in position.  There was a bit of ‘slam-bang’ rough-racing going on as the cars jockeyed for position, which really seemed to test the width/extremes of the road surface, perhaps scraping the left side a bit through one of the right-handers.  Then suddenly there was a pause; it was like a lady who owned one of the cars which was being driven in the race, popped up and had to evaluate the condition of a tire which had suddenly failed in somewhat spectacular fashion, as the tire had come off the rim and was not intact anymore.  She wanted to know how that had come about, whether it was the result of normal wear, or due to some specific mistreatment, etc.  So there were several people huddled around, at first just observing and I heard some comment about the tire being bald, like it was just completely used up.  The lady wanted to make the case that it was a mishandling or abuse situation, so she wouldn’t have to take responsibility for racing on a bad tire.  So then the biggest remaining piece of the tire was sort of gathered up and flipped over into its typical spot on the rim; it was clear it had torn open, and the tread surface definitely appeared worn, but not completely bald. But then someone pointed out a particular section which had obviously degraded substantially, like the outer surface was missing completely which exposed a sub-layer, and that area was right on the shoulder.  The guy then put forward the hypothesis/suspicion that this sub-layer got a sudden crack in it, and that caused the whole thing to fail in a more catastrophic fashion. He then demonstrated by pinching some of the exposed area of the sub-layer, which cracked easily and clearly showed how brittle it was.  That seemed to settle the investigation for everyone.

About