it’s still pretty useful tech given that I barely touched the brake pedal from a trip from North London/M25 to Braintree and back the other day
As I said earlier my VW Golf TACC story is old, so technology will have moved on, but it would not slow the car down, in regular moving traffic, below some threshold (I forget, but let's say 25 MPH), at that point it would just sound alarms. The alarm noise was the same for everything, so you had to look down and read the dash to figure out what the emergency condition was (remember: car is slowing down with traffic, gets to trigger point, and then for no obvious reason [to the driver] sounds an alarm and releases the brakes ...)
Tesla: In traffic: slow down with car in front even coming to a stop ... and then when car in front sets off again the Tesla does too. Even on a tight bend. And: even if the car in front is pulling onto a roundabout
But also if the car in front is half asleep and does nothing, but car in front of that slows down suddenly, then Tesla will slow down anyway
an early warning system in the event of me drifting by accident or god forbid falling asleep. It does respond with the wheel vibrating and the car beeping at you
Definitely a benefit of using AP. AP might detect something that the driver doesn't - side incursion from blind spot, for example, in that case it will move the car in lane to avoid the danger, let alone straight line braking for slowing traffic ahead. Tesla has lane departure alert (when manual driving) too, and many of the safety features are working all the time - accelerate hard at the car in front, intending to overtake, and Tesla will alert the impending straight-line collision ... that's quite fun for a passenger demo
- but I think when on AP there are more things active and working to save you.
The biggest problem with AP is complacency. Mile after mile, in my case tens of thousands of miles after miles, of faultless AP driving and there is temptation to let it just get on with it. I've never had AP do something daft, but there have been fatalities where driver clearly had time to take over and sort the situation out ... but didn't. Me = one hand on wheel at all times, supervising, no exceptions.