Adaptive Cruise Control. I make a lot of trips between Indy and St. Louis to check in on my dad. I-70 has LOTS of truck traffic and I tend to drive a few MPH over the speed limit. I constantly find myself coming up behind a truck with faster traffic in the left lane. I used to cancel and re-engage cruise control dozens of times on that trip. With ACC I just go into following mode until the left lane traffic has passed. It makes for a much more pleasant drive.