You'd generally think that Tesla buyers and Tesla fans would be more sophisticated about car technology like adaptive cruise control -- which I've had on my Prius since 2011. And that works the same way as tacc. Even worse because it only has a radar and not a camera. It would never lock onto a car that was already stopped. But the first accident I hear about a driver using adaptive cruise and aiming the car at a parked car is with a Tesla. And the level of fear and hand wringing is surprising.
Indeed, bhzmark probably hit the nail on the head: The reason the Model S accelerated, quite likely was because it "lost" the car in front because it stopped. TACC radar only basically senses moving cars. I've driven TACC on Germans for a decade and this was especially a limitation in the first one radar implementations.
Though, even those first TACC's I drove, usually managed to slow down the car up to the point where they just turned the TACC off (and thus no acceleration but immediate slow down) because they weren't in control anymore, rather assuming something is in front (sometimes when something actually turned away from the road) than the other way around.
Later TACC implementations have gotten better (some Germans use two radars in front plus the camera), and Tesla has a camera in front not just a radar, so it should have recognized a car that stopped in front... I mean, it doesn't sound impossible the Tesla implementation failed, not just that adaptive cruise in general failed. Of course, an attentive driver would probably have been able to correct that failure, but no way should the car just accelerate in that scenario, if the conditions are good.
Later German TACC implementations definitely have worked "stop and go" very reliably. If the Model S really failed this scenario so miserably that it was following the car in front, sensed it was slowing down, but then lost it, I'm not sure that is what I would have expected from a TACC car in 2015. Maybe back in 2005. Drive a new high-end Audi in that scenario and I'm almost 100% sure it would stop, unless the location is a tunnel or it is snowing terribly, and in that case it would just turn the TACC off entirely.
No matter, always funny to see a thread on TMC talk more about the original poster's character and suspect actions than the issue at hand.
It is so expected.
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Wrong characterization. While a lot of these systems are advertised as working with stop and go traffic, they are not designed to detect stationary vehicles and will react in a similar way to a stopped vehicle that it did not track or a moving vehicle that braked but it lost track of because it deviated out of radar range (from a bend or not being in middle of lane).
Here's Mercedes' DISTRONIC PLUS which is advertised to work in stop-and-go traffic:
http://www.m-sedan.com/tips_for_driving_with_distronic_plus-4465.html
Same with BMW's "Active Cruise Control with Stop & Go function":
http://www.bavarianmw.com/guide-2677.html
Those are the exact same situations where people complained the Tesla TACC "failed" and other brands would not. It all comes from a misunderstanding of what ACC in general is supposed to accomplish. All it does is follow the car immediately in front of you at a set distance (accelerating and moderately braking to maintain that distance). Anything that deviates or interferes with that is not what the system is designed to handle (like the oft quoted situation where the car you were following leaves the lane and there's a stopped vehicle in front and driver wants to stay in same lane).
In reality, later German ACC implementations can often recognize stationary cars. It used to be worded "will not", now it is just worded "may not" when referring to stationary objects. The addition of frontal camera, more radars and use ultrasonics has made ACCs much more reliable.
That said, what interests me is - was Model S tracking the car in front, i.e. was it still moving within the range of the TACC, or not. If Model S was slowing down but then lost it and decided to accelerate, it probably mistakenly thought the car in front turned away.
If so, that is still a pretty bad mistake to make. I've seen German's err on the side of caution in that case, never accelerate, usually slowing down just in case when the car in front turned away and taking their good time before accelerating again.
In any case, before anyone of us says more on the topic of how reliable Tesla's ACC is compared to others, we probably have to admit we don't know. We just don't have enough data to determine that, only anecdotal information.
