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3 day old import P85D crashed while using TACC

Shawn Snider

Jul 30, 2014
BC, Canada
If that picture is taken before the accident, then driver is 100% at fault, he drove it knowing something was wrong.

If that picture is taken after accident, doesn't mean anything, as during the accident could have broken any number of the car systems.

The picture above shows Thu, 7 May. The first pictures (of the crash) show May 8. So on the 7th the car told him the features were unavailable, crashed the next day.

If I were driving my family around, in a brand-new, never-before-experienced technologically advanced car, I would NEVER rely 100% on the functionality of the vehicle to keep my family safe. Call me paranoid, but some things are too important to leave to faith.

Also, I read a post earlier mentioning the license plate possibly blocking the TACC sensor in the front grille. Would it beep or otherwise notify you if it were? (ie; adverse weather disabling the sensor/camera) Maybe the 'dealer' (or whoever put the license plate on) he bought it through put the plate over top of the sensor? I'm pretty sure it would warn you though..

Best of luck!


Jun 19, 2014
IMHO, a useless accessory.
I am the active component that pilots my cars. I can't ever imagine a machine ever having the perception of the human pilot.
Yep, there are individuals that may find cruise control an aid for their physical limitations.
Yep, drivers do make mistakes and if the car can alert the driver of a pending situation with a heads up display it might be of some assistance rather than just another distraction.

But the opposite is true too. In situations where it prevents an accident, there will be no mention in any newspaper or statistic in any database. It's not necessarily the case that it saves a driver who wasn't paying attention. It might save a driver who was paying complete attention since it can do things faster than are humanly possible.

Getting back on topic, it's clear from the user manual that Tesla said it may not detect stopped cars, shouldn't be relied on, etc. There's no reason to sue anybody unless you make some sort of claim and they deny responsibility. So even if Tesla were wrong, it still wouldn't make sense to sue them here. Nevertheless, Tesla does want the vehicle to work in this scenario. They don't guarantee it, but I'm sure they are more than interested in what happened. With the latest maintenance release of 6.2, the car has gotten much better at detecting stopped vehicles. I've always made a point to assure that the CC symbol was blue and not gray before the car got anywhere near rear ending anybody, and it's gotten much better at that. It doesn't mean I will stop paying attention.

Nobody here can say what Tesla will or won't do. It can range from them saying sorry but it's your fault, to them saying that they will give you a new car but it's your fault and you have to sign a non-disclosure agreement and a statement denying any responsibility on their part. Or it could be anything in between. That's a very broad range. In theory it could be broader but I doubt that Tesla would sue you so I'll leave it at that. I hope Tesla does as much as possible to help you and it will be a long time before they tell customers that they are offering autonomous vehicles rather than autopilot.

Now getting back off topic, there was a time I was using ACC in another vehicle. There were two cars in the next lane over. One was reckless and tailgating the other within a few feet. The lead car wanted to get out of the way and change lanes in front of me when it was safe to do so. I had no way of knowing what either car would do, but the lead car started to change lanes when it was a bit more than a car length ahead of me. Just as it was about to change lanes (presumably right after the lead driver checked his mirror and saw that he was clear) the reckless driver decided to cut me off within a couple of feet of my bumper and then speed up. Since the car that was in front of it had already determined that it was safe to change lanes, it did exactly that. But by that time, its rear bumper was about three feet behind the front bumper of the car that had just cut me off, and that car was likely in its blind spot when it started moving. So that car slammed on its brakes full force within a fraction of a second of cutting me off at highway speed. My car applied its brakes immediately, tightened the seat belts, and pre-pressurized the master cylinder so that by the time my foot got there I was pressing a rock hard pedal.

The typical human reaction time to that sort of event is about a second. Since the car that cut me off left me with a following distance of perhaps a 20th of a second, it would not have been humanly possible to get my foot from the gas pedal to the brake pedal, which also takes about a second. The car avoided an accident and it had nothing to do with me being inattentive. It was at a high speed and I could have been killed if not for the car's actions. I'm also pretty sure that the car changed lanes without signalling, but even if it had, chances are my A pillar would have blocked it from view. I most likely assumed that it wouldn't change lanes since the vehicle in front was signalling a lane change, but since it had been tailgating so closely, it might have been unable to see anything on the vehicle in front of it short of the rear window. Perhaps my foot was even moving toward the brakes already. I don't quite remember but I know the car reacted before my foot could get there.

That's why I was hesitant to even consider the MS until it had autopilot. It has nothing to do with relying on safety features. I don't rely on airbags to save me and use that as a justification to crash my car. Safety features are there for the worst case scenario. Convenience features such as typical use of TACC are helpful, can double as safety features in moments of distraction or in situations like mine, but if you rely on them when common sense tells you to use the brakes, that's not a reasonable use of technology.

As for McDonald's that's a completely different story. If you read all the facts, it's far from frivolous even though it seems that way on the surface. This incident wouldn't stand a chance in court since Tesla made it clear from the beginning what to expect.


Dec 11, 2014
Fairview, TX, United States
I spent a good twenty minutes typing out a detailed response to your post and the backspace key changed the page and all three paragraphs were gone :cursing:.

My main point was that autopilot-features need to become incompetence-resistant (that phrase is not directed at OP). Many future drivers will use autopilot features in far less than favorable conditions with less than desirable driving habits. Just because Tesla can't be sued can't mean they can't be harmed. The last thing they, or other auto manufacturers, need is the consumer or regulatory perception that these technologies are unreliable or inherently unsafe because of a TACC or Auto steering-blamed crash.

I completely agree with your technology-shortened response. The key word in your response is "blamed". No matter how "incompetence-resistant", or not, blame will be pointed at the new and unfamiliar. Consider the infamous "Bought an RV, put it on cruise, went in the back to make a sandwich" story. Absolutely untrue, yet still widely circulated, even occasionally by a "news organization". The tech literally does not matter; perception does.

That's why it is incredibly important that everybody keep chanting: The driver is responsible. The driver is responsible. Cruise or not, TACC or not, Tesla or Mercedes or Kia... the driver is responsible.

That would be the best protection Tesla could receive from harm.


Jun 19, 2014
The picture above shows Thu, 7 May. The first pictures (of the crash) show May 8. So on the 7th the car told him the features were unavailable, crashed the next day.

Also, I read a post earlier mentioning the license plate possibly blocking the TACC sensor in the front grille. Would it beep or otherwise notify you if it were? (ie; adverse weather disabling the sensor/camera) Maybe the 'dealer' (or whoever put the license plate on) he bought it through put the plate over top of the sensor? I'm pretty sure it would warn you though..

Best of luck!

Yes, it would warn you by giving you a message that the driver assistance features are unavailable and you should contact Tesla service. At that point you know not to rely on them until Tesla investigates it.


Aug 20, 2006
If anyone cares, Model S manual is online here:
[Page 60]
Traffic-Aware Cruise Control uses a camera mounted on the windshield behind the interior rear view mirror and a radar sensor in the center of the front grill to detect whether there is a vehicle in front of you in the same lane. If the area in front of Model S is clear, Traffic-Aware Cruise Control is designed to drive consistently at a set speed. When a vehicle is detected, Traffic-Aware Cruise Control is designed to slow down Model S if needed to maintain a selected time-based distance from the vehicle in front, up to the set speed. Traffic-Aware Cruise Control does not eliminate the need to watch the road in front of you and to apply the brakes if needed.
[Page 61]
Warning: Do not depend on Traffic Aware Cruise Control to adequately and appropriately slow down Model S. Always watch the road in front of you and stay prepared to brake at all times. Traffic Aware Cruise Control does not eliminate the need to apply the brakes as needed, even at slow speeds.
Warning: Traffic-Aware Cruise Control can not detect all objects and may not detect a stationary vehicle or other object in the lane of travel. There may be situations in which Traffic-Aware Cruise Control does not detect a vehicle, bicycle, or pedestrian. Depending on Traffic Aware Cruise Control to avoid a collision can result in serious injury or death.
Warning: Traffic-Aware Cruise Control may react to vehicles or objects that either do not exist or are not in the lane of travel, causing Model S to slow down unnecessarily or inappropriately..
Warning: Traffic-Aware Cruise Control may misjudge the distance from a vehicle ahead. Always watch the road in front of you. It is the driver's responsibility to maintain a safe distance from a vehicle ahead of you.
Warning: When you enable Traffic-Aware Cruise Control in a situation where you are closely following the vehicle in front of you, Model S may apply the brakes to maintain the selected distance.
Warning: Traffic-Aware Cruise Control has limited deceleration ability and maybe unable to apply enough braking to avoid a collision if a vehicle in front slows suddenly, or if a vehicle enters your driving lane in front of you. Never depend on Traffic-Aware Cruise Control to slow down the vehicle enough to prevent a collision. Always keep your eyes on the road when driving and be prepared to take corrective action as needed. Depending on Traffic-Aware Cruise Control to slow the vehicle down enough to prevent a collision can result in serious injury or death.
Warning: Driving downhill can increase driving speed, causing Model S to exceed your set speed. Hills can also make it more difficult for Model S to slow down enough to maintain the chosen following distance from the vehicle ahead.
Warning: Traffic-Aware Cruise Control may occasionally brake Model S when not required based on the distance from a vehicle ahead. This can be caused by vehicles in adjacent lanes (especially on curves), or by stationary objects.
[Page 64]
Warning: Many unforeseen circumstances can impair the operation of Traffic-Aware Cruise Control. Always keep this in mind and remember that as a result, Traffic Aware Cruise Control may not slow down or may brake or accelerate Model S inappropriately. Always drive attentively and be prepared to take immediate action.
Warning: Traffic-aware cruise control may not brake/decelerate for stationary vehicles, ...
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Feb 8, 2014
Los Angeles
+1 TEG

Although I did not read but the 1st post from the OP. I'm glad you and the family are OK, but you clearly did not read the manual. You are in control of the car at ALL TIMES, you are fully responsible for everything it does. Period.

I reiterate, I'm so happy the fam is ok. That's all that matters. Start putting the cash together to get a new Model S rather than wasting it on Lawyers in a case that you will clearly not win.


Well-Known Member
Oct 28, 2012
Skaneateles, NY
This was bound to happen. TACC is not to be used anywhere else but the highway and it is NOT designed to stop on time before an accident. If you have the latest software the emergency braking should kick on if an object is detected BUT ONLY TO REDUCE THE IMPACT. It will not stop on time to prevent the impact. This is written in the manual and I've brought this topic up on the forums before saying that it's bound that someone doesn't read the directions and will get into an accident and will blame tesla even though it's their fault that they didn't read the directions and understand the systems. I feel for you but I don't think there is anything you can do about it except hopefully getting insurance to cover you, sorry. I hope you can your family were not injured.


Well-Known Member
Oct 28, 2012
Skaneateles, NY
Um, even without TACC, the collection detection and braking should have kicked in and prevented this crash. Not even a weird situation where the car in front gets out of the way and the car in front of that one is already stopped. This is pretty incredible. That said, I wouldn't start with threatening to sue Tesla. I'd be surprised if they didn't step up to fix this whether it be replacing the car or covering the increase in your insurance premiums.

VERY VERY WRONG AND BAD INFO TO TELL PEOPLE. If you tell this to people or people read your post and other owners believe you, you may cause more accidents. The system is designed NOT TO PREVENT collisions but rather REDUCE THE IMPACT of an unavoidable collision. Let me highlight this right in the manual for you:





Aug 19, 2014
Northern California
This was bound to happen. TACC is not to be used anywhere else but the highway and it is NOT designed to stop on time before an accident.

Agreed. As MsElectric pointed out, though, it is very important that people realize that the same thing could happen on the highway. Let's say you're traveling down the highway with TACC set at the 65mph speed limit. Traffic is stopped in your lane ahead but the car in front of you doesn't slow down. Instead, the car in front of you changes lanes right before it would have otherwise hit the car stopped in your lane. I suspect the result would have been the same as or worse than what happened to the OP if relying entirely upon TACC to stop the car.

My point is that we need to be just as observant on the highway using TACC as we would have to be on surface streets.

Personally, I wouldn't use it on surface streets because I don't like using my brakes. I prefer the regen braking whenever possible which is more efficient for range and my brakes should last forever!


Mar 11, 2015
The Tesla doesn't have collision avoidance, like in the D event showed here.

It doesn't sense stationary objects but only moving ones for the TACC. So the Tesla would only automatically brake for a vehicle it already locked on to.

Maybe when it can park itself, the collision avoidance will be enabled.
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Todd Burch

Voltage makes me tingle.
Nov 3, 2009
Smithfield, VA
Briefly, I think the car's system not perfectly working and this was not completely his fault.

The systems are continuously performing checks to ensure that they're working properly, and if they're not, they immediately disable themselves.

If he *really* believes the system was working improperly, he can feel free to try to sue Tesla. He will lose, and in the process lose a whole bunch of additional legal fees. Not only that, but I'm willing to bet Tesla has logs from the vehicle showing that it was behaving as expected.


Active Member
Jul 21, 2013
@haggy. +1 . I wasn't going to buy a Tesla either until it had acc. Acc/collision avoidance saved me from a similar close call as well in another car. It applied the brakes faster than humanely possible. Along with abs and stability control and seat belts and airbags, acc has saved lives.


Active Member
Mar 12, 2015
Ohio, USA
I agree this is a limitation with the current technology. And it will continue to remain a limitation until the car takes over steering. Once the car knows what direction it will take, it will be much better at differentiating between relevant and irrelevant stationary objects.

Yea. Eventually this weakness will go away, but not until you have a system like drive PX that can intelligently identify a truck from a car from a person from a road railguard.

As many others as mentioned though, this was definitely a misunderstanding of what TACC is supposed to be used for.


Mar 11, 2015
Sunnyvale, CA
Neither of them calls their system Autopilot either...
The term "Autopilot" has been used for a long time in aviation despite the fact that it often doesn't do much more than e.g. level the wings, keep altitude, stay on a compass heading, and/or fly to a beacon/waypoint.
Still today, when pilots use newer features like "Auto land", they are still responsible, expected to pay very close attention and intervene if necessary.

I don't see harm in Tesla having adopted the term for use in the automotive world.


Active Member
May 16, 2012
> imagine if you were on a 2 hour journey some place and you have been using TACC for a while and have gotten comfortable with and complacent with it as just about any human being would be after a while. [MsElectric]

Here's your twisted logic.

TACC is a passive safety feature operating in the background. How can a driver get 'comfortable with it' unless s/he was GAMING THE SYSTEM, i.e. operating in a purposely foolish and dangerous manner (criminal negligence) to 'test how it works'?

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