Distance 1-3 are too close to the car in front for anyone sensible. If you drive that close to the car in front on a driving test, you’d fail. If anything I think it needs a 8-12 adding as well. If people left proper gaps, there would be far less accidents AND traffic would flow better.
TACC measures distance in seconds of following time, not car lengths.If you used to enjoy the thrill of driving at above 85mph within 1 car length of the car in front I can see how that's been crippled.
I don't know why 1 second was even in there in the first place given that it's only a level 2 system and requires active driver supervision. Seems odd that you can set a car that will handover to you with zero notice to drive so close to the car in front that you're inside the fairly universally accepted 2 second safe following gap.