Forward Collision Alert saved my *** this weekend

[AdamHLG]

Fellow enthusiasts.... we often come to these forums and discuss the features we don't have yet. This post makes me appreciate a feature we do have.

What I am about to tell you is an accident averted because forward collision alert actually worked and saved what would have been my own driver error. This weekend en-route to the beach (about a 3 hour drive) was a mix of 65-70 mph driving, at times, and bumper to bumper traffic, at other times, and everything in between. This typically would have been a stressful drive, but auto-pilot is amazing as long as the driver is attentive.

However, because of the nature of the drive, construction along the way, or other factors, sometimes I had auto-pilot engaged, and other times not. About half way through the trip, I encountered moderate stop and go traffic. Auto-pilot was not engaged and I was following a car in front of me at about 35 mph. There were about 5 - 7 car lengths between us. I reached over to grab something and took my eyes off the road for what would have, in my mind, been a split second, but in reality was probably 3 seconds - tough to know exactly. What I do know is that while my eyes were off the road, I heard the "BEEP BEEP BEEP BEEP BEEP" and quickly looked forward and saw the red brake lights of the car in front of me RAPIDLY approaching my 35 mph moving vehicle. The car in front was almost stopped at that point. I was able to brake hard and make a very rapid controlled emergency stop as my heart sank into my feet. Luckily the car behind me stopped on time as well. Crash averted.

My wife said to me (as she was oblivious to what just happened) "I hate those various beeps and sounds your car makes" and I was just sitting at a stop with my jaw hung open with the knowledge that, absent those beeps, I likely would have hit that car. The fact she was oblivious to what happened shows my technical skill at executing an abrupt emergency stop

It only takes one of those incidents to remind me that distracted driving is no joke. I consider it a strong warning to me that I better not take my eyes off the road again auto-pilot or not - not even for a split second. It really can happen that fast. The car in front must have started to brake the instant I lost eye contact with the road.

So, thank you Tesla engineers because despite the rare false alarms I have received via the forward collision alert, this time is saved my ***.

I took the time to post this in the hope that other can learn from my own close call. Be safe out there!!!

 

[Peteski]

Glad it worked for you. I have mine set on "early" warning for maximum effect. It's a good feature to have for sure.

 

[chillaban]

That's a great story. I actually have moved my FCW setting from Medium to "Early" to give myself more opportunities for situations like this. It's really really easy to get distracted for a split second. I'm embarrassed to admit I have multiple stories like this.

I was in San Francisco once (crazy city to drive in), running late, and suddenly my Waze conked out and told me to turn left immediately. Traffic was fairly dense in those lanes, and this area does not allow U-turns for miles. It would've delayed me long enough that I felt motivated to force Waze to re-route.

Before I started playing with my phone, I had 5 car distances to the guy in front of me and we were both going 25mph or so. I don't think I looked down for more than 3 seconds, but suddenly the FCW went off. When I looked up, there was a diagonal taxi cab stopped in front of me. I slammed on the brakes just in time. I don't even know how he got there, but I presume he was trying to cut across.

This is something I deeply appreciate of AP2, as an aside. It recognizes cars from far more angles and situations compared to AP1, which pretty much strictly requires the rear of the car to be head-on to you.

A less fortunate story: My friend in a 2017 Audi rear-ended someone because in the split second he was checking his blind spot for a lane change, the car in front decided to suddenly stop on a 50mph road. The camera-based collision warning system (which was highly rated by IIHS) did not even go off. He's still paying the insurance premium from this accident, and understandably lost some trust in his car's safety features.

I really think, despite all of the media flak, Tesla's FCW system is one of the best on the market in terms of the wide variety of circumstances where it's able to deliver a relevant alert. And I think in 50k miles between AP1 and AP2, there's only been 1 case where I've gotten an alert that's genuinely a false alarm and not just me driving unreasonably aggressively.

 

[verygreen]

there's only been 1 case where I've gotten an alert that's genuinely a false alarm and not just me driving unreasonably aggressively

Seeing as how you are in Bay area, you seem to have a super low bar on the "unreasonably aggressively" definition. That or cars don't often drive in two lanes at the same time in CA

 

[aesculus]

As much as I hate to admit it, it has saved me at least twice when perhaps I was not paying as much attention as I should have been.

 

[gilscales]

I have mine set to "Early" and it has generated lots of early warning beeps when I was paying attention but to be fair we live in one of the more congested areas so people are setting it off just jockeying for one more spot, One time it did beep when I was not fully aware of the early stopping traffic and I was glad for that, makes all the other "Unnecessary" beeps much more tolerable!

 

[TexasRat]

I have mine set to moderate and it did go off once this weekend and I was thankful that it did as it helped me ensure I stopped in time. The noise is pretty annoying though, so I'm a little hesitant to set it on early if it's going to go off a lot. Great feature!

 

[Xenius]

I won't admit this to my wife, but pretty sure autopilot prevented a sleep deprived me from falling asleep at the wheel on a 6+ hr trip yesterday...

 

[mtndrew1]

FCW has saved my butt twice, once while initiating the emergency braking.

Both times were when the car ahead of the one I was following was having an incident and I couldn’t see what was happening prior to the cars ahead of me slamming on their brakes.

I’m certain that one of these incidents would have resulted in a collision as I was particularly exhausted that day. It’s a valuable feature.

 

[JSergeant]

I encountered moderate stop and go traffic. Auto-pilot was not engaged and I was following a car in front of me at about 35 mph.

I don't understand why you didn't just leave the TACC on. This is exactly the conditions when it's worthwhile.

 

[gilscales]

I don't understand why you didn't just leave the TACC on. This is exactly the conditions when it's worthwhile.

Many times I have turned off TACC as it was just to jerky in stop and go traffic and uncomfortable, other times it is performing smooth enough to leave on when full autopilot is not appropriate for the conditions so I can see why the OP may have it off.

 

[chillaban]

Seeing as how you are in Bay area, you seem to have a super low bar on the "unreasonably aggressively" definition. That or cars don't often drive in two lanes at the same time in CA

Do those situations trigger FCW frequently for you? I like driving aggressively in a lot of different ways, but after an absolutely horrible experience on my Audi with ABS activating inappropriately resulting in much longer braking distance than I had estimated, I don't chance following distance anymore. It only takes being burned once for that to be a life lesson.

So no, Bay Area or not, I don't risk how I regulate following distance.

 

[AdamHLG]

Many times I have turned off TACC as it was just to jerky in stop and go traffic and uncomfortable, other times it is performing smooth enough to leave on when full autopilot is not appropriate for the conditions so I can see why the OP may have it off.

This is true ^^^. However, I did not have it on because I was not really thinking about it. I had turned off both TACC and AP for some reason that I do not recall prior to that particular moment and I was simply driving the old fashion manual way (if you can believe that!).

 

[spectrum]

Random but related question — do I get this feature if I didn't get EAP?

 

[skip8jj]

FCW has saved my butt twice, once while initiating the emergency braking.

Both times were when the car ahead of the one I was following was having an incident and I couldn’t see what was happening prior to the cars ahead of me slamming on their brakes.

I’m certain that one of these incidents would have resulted in a collision as I was particularly exhausted that day. It’s a valuable feature.

I have experience what you describe. The scariest and first time our MS reacted was in the fast lane in 5 PM traffic on I15 in SLC, Utah. Really surprised us. A car ahead of the car we were following missed a left exit lane and drove over the median to get on the off ramp.

 

[mxnym]

Random but related question — do I get this feature if I didn't get EAP?

I believe so. It is listed as a standard safety feature in at least some of the marketing material.

 

[KerryOH]

Random but related question — do I get this feature if I didn't get EAP?

Yes, I don't have EAP but FCW works well in NJ and Delaware traffic.

 

[spectrum]

Yes, I don't have EAP but FCW works well in NJ and Delaware traffic.

Thank goodness! Do you still see the cars/trucks on the road around you in the IC?

 

[verygreen]

Do those situations trigger FCW frequently for you? I like driving aggressively in a lot of different ways, but after an absolutely horrible experience on my Audi with ABS activating inappropriately resulting in much longer braking distance than I had estimated, I don't chance following distance anymore. It only takes being burned once for that to be a life lesson.

So no, Bay Area or not, I don't risk how I regulate following distance.

Yeah. FCW activates when you are quickly approaching a car that is at least partially in your lane (no matter how small), this happens when: you are overtaking somebody, or they bump into your lane/drive in two lanes for whatever other reason (also when they are turning/changing lanes), you can see one example of that in my "Tesla/Navigon maps comparison" video, btw, and it's super easy to reproduce) - probably working as designed even if I don't fully agree with that particular design decision and would like it to be at least somewhat more tolerant. I have left mine at medium, btw.

Other cases where I see FCW activating - poorly marked twisty backroads where it picks up oncoming cars and warns you of imminent collision. The IC display shows a red car that matches the oncoming car and eventually it "hits" your car on display as it passes by and then like a ghost continues further.
Sometimes it's confused by overhead signs and you get a phantom FCW where the car in front of you turns red but does not get any closer, yet the beeping persists until you pass the sign and then the beeping suddenly stops and the car you are following turns white again.

That said it also tends to beep when I am approaching stopped traffic (not every times), we'll chalk these as working as designed as well since sometimes I do approach them somewhat fast I guess.

Of course I am still not turning mine off because well, I can tolerate beeping and hey, it might save me too one of those days.

 

[MorrisonHiker]

I don't understand why you didn't just leave the TACC on. This is exactly the conditions when it's worthwhile.

I almost always use TACC but there's one spot where I usually turn it off. Two lanes from one highway (C-470) merge into one lane right where they connect with I-70. While the right lane ends and there are plenty of signs indicating this, half the cars stay in it instead of zippering and merging into the remaining lane. I'm usually in the middle lane and cars are trying to get into my lane from the left (I-70) and right (C-470 lane that ended). Sometimes the speed at this point is 20 mph. At other times, it's 70 mph. If I use TACC there and the car in front of me moves left onto I-70, the car will try to instantly accelerate to 65 mph. While I have the right of way, cars on the right (in the lane that really already ended) always try to cut over and if my car was accelerating greatly, they would either hit me or think that I'm trying to prevent them from merging. IF everyone would just zipper and merge politely, it wouldn't be a problem but due to clueless and inconsiderate drivers, I feel it's actually safer to disable TACC at this location.

Yes, I could just constantly adjust TACC here but with the recent updates the car is already adjusting the set TACC speed from 70 to 65 to 60 to 55 back to 65, etc. and it is just easier to handle things manually and anticipate what drivers will be doing on either side.