So far I've been impressed enough with the HW4 Teslas that I haven't had them do anything that I had to intervene to correct or prevent. It's pretty amazing at how well it handles all kinds of things - construction, weird merges, road debris. This morning, there was a tire in the middle of the road, which caused traffic ahead of me to slam to a halt. Mine had to brake hard enough that ABS engaged, and then navigated around the tire. I was impressed.