Accident for unable to brake efficiently: Tesla's or my fault? [early 2020]

[Ol'Blue]

In this situation, the brakes were not to blame at all.
If you want to blame it on the car, blame it on the tyres, but the driver could have avoided the accident in any case.

this is why I mentioned “you must have slammed on the brakes too hard”. The key word being “you”

doesn’t matter how good a braking system is or isn’t, if you’re too aggressive on inputs on a vehicle, you can cause it to lose control. This was my point. He hit the brakes too hard in an sort of shocked sort of way. This triggered a chain of events. Not to mention, too short a stopping distance.

 

[Dangerous Fish]

this is why I mentioned “you must have slammed on the brakes too hard”. The key word being “you”

doesn’t matter how good a braking system is or isn’t, if you’re too aggressive on inputs on a vehicle, you can cause it to lose control. This was my point. He hit the brakes too hard in an sort of shocked sort of way. This triggered a chain of events. Not to mention, too short a stopping distance.

It doesn't matter how hard he slammed on the brakes. If the driver realised the car wasn't going to stop in time he should have steered to the right into the 'escape' route. 1st rule of defensive driving is always leave yourself an escape route if it all goes pear shaped

 

[KenC]

One thing not mentioned, roads with hot tar patches in cracks are notoriously slippery when wet. They're worse than wet paint. As you drive, you should always be aware of the vehicles around you, and in particular, whenever you are braking, should be aware of whether you have an empty bailout area to your side. As soon as you suspect your car is not braking quickly enough, you should start edging towards the bailout zone, in case you need to make a quick exit. The Audi on the left brakes exactly when he should have based upon a comfortable gap to the car ahead. That car was further ahead, so your braking should have started exactly at the same time as the Audi's. As you pass the Audi, you're already going too fast, for a comfortable stop, and you should have sensed that and should already have been starting to prepare to bail, because you're getting uncomfortably close to the Hyundai given your speed.

Here the light has just changed to yellow, and the Audi has already hit his brakes. His gap to the car ahead is about the same distance as your gap to the Hyundai ahead. The Audi has started braking exactly at the time you should have begun braking.

At this point, you've passed the Audi, but the gap to the Hyundai is uncomfortably close given your speed. You should already be looking at the bailout area to your right, in fact, you should probably be edging into it.

Way late, and you're still going too fast. Hyundai is a few feet short of where the other SUV stopped, so you have even less room, you have tons of room to your right, you should already be halfway over there, as if you were coming from the right lane, merging. No one is going to be in that part, because they would have already merged, and all you have to check is the bike lane.

 

[BR666T]

Had you been using "standard" regenerative braking since new? I had been in my car and I realized on the first hard stop that the brakes had not bedded - they barely worked. After that I left the car In "low" for a while and performed a number of hard stops. Braking is MUCH better now.

I think Tesla should make this part of the break-in procedure for new cars.

 

[GoodManFrank]

Had you been using "standard" regenerative braking since new? I had been in my car and I realized on the first hard stop that the brakes had not bedded - they barely worked. After that I left the car In "low" for a while and performed a number of hard stops. Braking is MUCH better now.

I think Tesla should make this part of the break-in procedure for new cars.

Yes I've been using standard since new. Never tried hard stop brake test though. And I think regen wasn't slowing down the car as usual at that time...Maybe because of rain?

 

[BR666T]

Yes I've been using standard since new. Never tried hard stop brake test though. And I think regen wasn't slowing down the car as usual at that time...Maybe because of rain?

If you're using standard regen, I'm sure you barely use the brakes. The performance of brakes is poor until they are bedded and that comes only through use. The bedding process can be accelerated with multiple hard stops from highway speeds down to maybe 20 km/h.

 

[Big Dog]

driving too fast for conditions, and all-weather tires.

 

[LongRanger]

Not sure I understand why this is a Tesla question.

 

[smatthew]

FCW didn't trigger.

This is an interesting discovery. There was indeed a dive of nose, or say bounce down of the view, around 11.5-12s, but I started braking way before that, with regen first. Maybe it's just a bump on the road, or maybe that's when I slammed the pedal hard when I realized regen won't stop the car in time.

At some point you thought regen would be strong enough to not hit the car in front of you? At 50mph? Regen has never been that strong.
Honestly, you would have been better off if you had let AutoPilot drive...

 

[smatthew]

Had you been using "standard" regenerative braking since new? I had been in my car and I realized on the first hard stop that the brakes had not bedded - they barely worked. After that I left the car In "low" for a while and performed a number of hard stops. Braking is MUCH better now.

I think Tesla should make this part of the break-in procedure for new cars.

Every Tesla had the brakes bedded in on a test track. The car tracks the status of the brakes and performs preventative maintenance when required to keep brake surfaces clean.

 

[acarney]

Looks like you’re at fault. Wet roads and grease on them absolutely can do that.

 

[GoodManFrank]

At some point you thought regen would be strong enough to not hit the car in front of you? At 50mph? Regen has never been that strong.
Honestly, you would have been better off if you had let AutoPilot drive...

Use regen to brake is how most people drive a Tesla, right?
For me, I'd typically use regen first and then apply brake when speed is lower than about 15mph to come to a full stop. I might have overestimated the power of regen under that road condition.
And 50mph sounds way too fast. If I were at 50, other cars were also speeding. Don't know if there's any way to infer speed from video.

 

[Dangerous Fish]

Every Tesla had the brakes bedded in on a test track. The car tracks the status of the brakes and performs preventative maintenance when required to keep brake surfaces clean.

That's just not true. The brakes are not fully bedded prior to delivery, but that is largely irrelevant in this case.
What is this preventative maintenance you refer to and where is it documented?

 

[Dangerous Fish]

Use regen to brake is how most people drive a Tesla, right?
For me, I'd typically use regen first and then apply brake when speed is lower than about 15mph to come to a full stop. I might have overestimated the power of regen under that road condition.
And 50mph sounds way too fast. If I were at 50, other cars were also speeding. Don't know if there's any way to infer speed from video.

If you set the car into hold mode you can stop the car without using the brakes as long as you judge it correctly.
You continue to try and blame your accident on the car but you were at fault, pure and simple.

 

[evfeh]

Totally your fault.

 

[StellarRat]

Hey all, I've got into a small accident couple months ago and hope we can discuss about this.

Dash cam recording goes first:

(I only blurred the license plate for privacy concerns. Nothing else edited, for example speed, resolution, color, etc)

This rear end accident happened last year, and luckily nobody was hurt. My Tesla insurance covered this, and I told them the brake was not working as intended right after the accident. I also called Tesla roadside assistance & service center to report this malfunction, and they promised I would get an investigation result within 8 weeks. Not surprisingly that didn't happen. So I'm still wondering who is at fault in this accident, because it seems obvious to me that the brake wasn't right. Or maybe I could be wrong and need to be more careful in similar situations.

Here're some key conclusions:

1. The road was wet but not raining when it happened, actually it showered in the morning and stopped about half an hour ago. Temperature was around 50°F - 70°F (10°C - 20°C), speed limit is 35mph.
2. My Model 3 LR AWD was very new with 2000 miles on it. It has the original 18'' aero wheels & tires. Manual driving all the time, no autopilot involved.
3. I started to brake right after I see the red light & front car slowing down, with regen first and then immediately pushed brake pedal hard. I pushed as hard as I could and it still hit the front car.
4. The wheel was making deep clicking sound, indicating ABS triggered, but car just won't slow down and tire is making abrasive sound.
5. No collision warning, no auto braking or any other safety features triggered (I enabled all safety features).
6. Brake & regen still working after the accident. Have't tried braking hard though as I don't trust it any more.

Welcome to share your opinions. Thanks in advance!

Looks like you were going too fast. Also, you could see way ahead that there was a traffic light and a forced merge, why didn't you start slowing down a lot sooner? Everyone else started slowing down much sooner than you did. You passed people on both sides of you. If the ABS starting operating your brakes were doing everything they could. There simply wasn't enough space to stop at that speed because you started braking too late.

 

[sixela]

The ABS started working to ensure that you could still manoeuvre the car to the right,...

 

[GoodManFrank]

Thanks everyone. Most people agreed that the car is working properly in this accident, and I'm grateful for the useful information.

I'm not here to escape the responsibility as this case is already closed by insurance, and I know rear ending another car is 100% my fault. I'm here trying to figure out how would a Model 3 (or any vehicle) would perform under this condition. I was shocked and angry with the brakes after it happened, but now from your posts I know this is what brakes & tires supposed to behave in wet & sloped road. I don't have much experience driving in rainy season and would definitely learn from this. Drive slower, brake earlier and don't rely too much on regen.

As for steering away to avoid collision, I'd think twice and keep observing the traffic because I don't want to hit some cyclists, that would be much more serious.

Also I would consider changing the tires as some of you mentioned.

Hope this will never happen again. I'll keep updating if Tesla tells me anything.

 

[run-the-joules]

Not sure I understand why this is a Tesla question.

Over the last few years, I've come to the conclusion that a disproportionate amount of the Tesla community do not know *anything* about cars or driving, so very basic things that I thought everyone was taught come up in topics with alarming frequency.

 

[SageBrush]

I'll keep updating if Tesla tells me anything.

Better idea: don't waste the senior engineer's time