The first traffic law I was aware of that had changed over the years was U-TURNS. It used to be that you couldn't make a U-Turn unless it was posted that you could or you were in the middle of nowhere and no traffic was around. Now you just have to be careful.
I have talked earlier about the Speed Limit: the de facto speed limit is 10 miles above the posted limit.
If you were to follow at 1 car length per 10 miles of speed like you used to, or even at the 3-second rule, you will probably get honked out of existence. (I don't care, I still do.)
Apparently, the blind spot that used to exist is gone. This law of human anatomy has been repealed. That is what it seems like when you watch people in the lanes around you.