It's all confusing. From another part of the article: "TACC allows the vehicle adjust its speed based on the car ahead, decelerating or accelerating as needed."

It's all confusing. From another part of the article: "TACC allows the vehicle adjust its speed based on the car ahead, decelerating or accelerating as needed." So... it will decelerate, unless you are about to crash, then it will just chime? I guess it all makes sense because, also from the article: "Though new Tesla cars have superior hardware (according to Tesla, at least), the software that runs on the system is still being worked on. "