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Regenerative braking saved me from 2 accidents today

Hiline

Member
Supporting Member
Apr 16, 2022
637
887
Los Angeles
I just got home after driving on I-10 West through Los Angeles. If you’ve never driven here, you may not know how much drivers around here love switching lanes without notice, especially when they’re stuck in a slow-moving lane next to a fast-moving lane.

So anyway, I was in a fast-moving lane and a car in the next lane, with no warning, no signal, decided to just head straight out of the lane they’re stuck in without checking whether there was anyone behind in the next lane. I was going 20-30 mph faster than they and was maybe 2 car lengths behind. I had to lean forward off my seat to slam on the brake and as a result of momentum, but thankfully the braking started before I hit the brake. I came within a few feet of hitting the other car. Not once, but twice, in a span of half an hour.

I’m telling you, regen braking was inspired by LA traffic. Be safe out there and get yourself a Tesla!
 

KenC

Active Member
Sep 4, 2018
4,525
4,242
Maine
I just got home after driving on I-10 West through Los Angeles. If you’ve never driven here, you may not know how much drivers around here love switching lanes without notice, especially when they’re stuck in a slow-moving lane next to a fast-moving lane.

So anyway, I was in a fast-moving lane and a car in the next lane, with no warning, no signal, decided to just head straight out of the lane they’re stuck in without checking whether there was anyone behind in the next lane. I was going 20-30 mph faster than they and was maybe 2 car lengths behind. I had to lean forward off my seat to slam on the brake and as a result of momentum, but thankfully the braking started before I hit the brake. I came within a few feet of hitting the other car. Not once, but twice, in a span of half an hour.

I’m telling you, regen braking was inspired by LA traffic. Be safe out there and get yourself a Tesla!
Yep, when inches matter, those milliseconds of regen braking before your foot actually hits the brake pedal, can make all the difference.
 
Glad you’re ok! Regen braking really is a game changer for vehicle safety. It automatically reduces the chances of rear end collisions. In your case, it basically started braking early for you

I wonder if we'll see the same number of collisions overall, just transferring the Tesla hitting to car in front to the Tesla being struck from behind? Of course, in most cases, being rear-ended is better than rear-ending someone else, since the liability will be on the car hitting you. (And I don't think, except in rare cases, it's more dangerous to be struck from behind.)
 

afadeev

Active Member
Feb 28, 2019
1,111
1,310
NYC
Regen braking really is a game changer for vehicle safety. It automatically reduces the chances of rear end collisions. In your case, it basically started braking early for you

I love regen braking and one-pedal driving, but worshiping it as "safety" feature is a bit much.
It can also lead to a false sense of security. How you ask - by failing to apply your actual breaks immediately at the sign of danger. And by neglecting to press that brake pedal with purpose and conviction, enough to trigger ABS. If you didn't trigger ABS while braking in an emergency - you were UNDER-braking.

Like our unfortunate OP.

I was going 20-30 mph faster than they and was maybe 2 car lengths behind. I had to lean forward off my seat to slam on the brake and as a result of momentum, but thankfully the braking started before I hit the brake. I came within a few feet of hitting the other car. Not once, but twice, in a span of half an hour.

I am happy the OP came out OK from these two near misses, but if he needs to "lean forward off my seat" to engage the brakes, he is doing something VERY VERY wrong. And he needs to change his behavior patterns before he gets hurt, or hurts others on the road.

Either he is sitting too far away from the pedals (unlikely), is slouching and not paying attention (possible), or like 99% of the US drivers, has never practiced effective emergency braking and avoidance in his life and doesn't know how to brake properly (most likely).
*sigh*

Three (3) things that will actually improve your safety and reduce braking distances (and no, regen braking and auto-emergency-brake are not on the list):
  1. Learn how much pressure your brake pedal requires to engage ABS, and what that feels like to you when going straight or while turning at various speeds (lateral loads will move your torso, and will require more leg extension to get ABS to kick it). Practice safely without anyone behind you first.
  2. Ditch compromise all-season rubber and get proper performance tires. In addition to shorter stopping distances, your Tesla's handling will magically improve!
  3. If you really want to get good at #1 and learn to drive within 50% of your vehicle's potential, sign up for a proper driving school at your local track, with in-vehicle instruction.
More here:

HTH,
a
 
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I love regen braking and one-pedal driving, but worshiping it as "safety" feature is a bit much.
It can also lead to a false sense of security. How you ask - by failing to apply your actual breaks immediately at the sign of danger. And by neglecting to press that brake pedal with purpose and conviction, enough to trigger ABS. If you didn't trigger ABS while braking in an emergency - you were UNDER-braking.

Like our unfortunate OP.

HTH,
a
I doubt anyone “worships” regen braking as a “safety feature.” But one pedal driving with regen braking definitely increases the driver’s awareness of the road (e.g., anticipating when to ease off the accelerator to maximize regen braking to come to a complete stop) which increases safety (i.e., the car and driver are slowing down appropriately and sometimes sooner than an ICE car where you just mash the brakes). Of course, when there’s danger, the immediate reaction will be to hit the brakes and not just let regen do all the stopping.
 
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afadeev

Active Member
Feb 28, 2019
1,111
1,310
NYC
But one pedal driving with regen braking definitely increases the driver’s awareness of the road (e.g., anticipating when to ease off the accelerator to maximize regen braking to come to a complete stop) which increases safety (i.e., the car and driver are slowing down appropriately and sometimes sooner than an ICE car where you just mash the brakes).

Right, people definitely had no clue how to maintain "driver's awareness" before EVs came around.
I cringe at the thought of all those manual gearbox drivers endless bouncing off the 1st gear rev limiter, or stalling upon deceleration, since those poor souls have had no clue now to anticipate acceleration / deceleration and shift gears in advance. What a nightmare.

It must have required constant ongoing divine intervention for all those manual transmission vehicles to have been driven, at all.

BTW, I've seen no published studies that would prove the theory that manual transmission drivers had greater road awareness, and are thus safer, than drivers of automatic cars (or EVs, for that matter).
If you have, please share.

Of course, when there’s danger, the immediate reaction will be to hit the brakes and not just let regen do all the stopping.

You ain't kiddin'.

Unless, one requires the "lean forward off my seat to slam on the brake" intervening stage.
In which case, regen braking is all one's got. Which, I suppose, is better than nothing. But not as good a knowing how to properly brake, either.

a
 

TomT

Technical Maven
Mar 24, 2014
705
719
NE Georgia
Yep, when inches matter, those milliseconds of regen braking before your foot actually hits the brake pedal, can make all the difference.
If you watch carefully, regen braking actually does not start immediately, there is a slight delay. Thus, if you have normal reaction time, I'm not sure that it makes thay much difference as your foot would be on the brake pedal about the same time that regen really kicks in...
 
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Hiline

Member
Supporting Member
Apr 16, 2022
637
887
Los Angeles
If you watch carefully, regen braking actually does not start immediately, there is a slight delay. Thus, if you have normal reaction time, I'm not sure that it makes thay much difference as your foot would be on the brake pedal about the same time that regen really kicks in...
This is interesting. Do you know where I can read about the delay between foot-off-the-pedal and regen braking kicking in? I feel like it's immediate and what I've found online seems to say the same thing.
 

tm1v2

Active Member
Oct 18, 2021
2,034
1,681
USA
If you watch carefully, regen braking actually does not start immediately, there is a slight delay. Thus, if you have normal reaction time, I'm not sure that it makes thay much difference as your foot would be on the brake pedal about the same time that regen really kicks in...
@TomT That is true, I've felt the delay in every Tesla I've driven (many). And one non-Tesla EV I've driven seemed to have less delay in OPD regen kicking in and ramping up (which I liked).

However...when I disable regen braking in my M3P (Track Mode 0% regen), subjectively the brakes feeling mushier and worse in hard driving. (100% stock brakes.) Now I know that's placebo of sorts, the brake pedal only controls the friction brakes and I'm not changing anything about them by disabling regen. But what it tells me is that OPD regen helps make up for the lack of bite and responsiveness in the stock friction brakes.

So even though the delay you speak of is real, I can feel it too, it's minimal enough that I think OPD regen does benefit braking reaction, even when you're fast switching to the brake pedal (like during very focused hard/fast driving). Maybe if you were left foot braking it wouldn't matter at all, but I don't do that aside from bedding brake pads.
 
Right, people definitely had no clue how to maintain "driver's awareness" before EVs came around.
I cringe at the thought of all those manual gearbox drivers endless bouncing off the 1st gear rev limiter, or stalling upon deceleration, since those poor souls have had no clue now to anticipate acceleration / deceleration and shift gears in advance. What a nightmare.

It must have required constant ongoing divine intervention for all those manual transmission vehicles to have been driven, at all.
No one said that driver's awareness did not exist before EVs, as your statement implies. I said, "regen braking definitely increases the driver’s awareness of the road" - which I believe it does. I also believe that driving a car with a manual transmission (which I did exclusively for about 20 years) increases road awareness, too, because of the need to constantly engage both hands and feet to ensure you're in the proper gear for the circumstance. Not sure if you're being sarcastic.
BTW, I've seen no published studies that would prove the theory that manual transmission drivers had greater road awareness, and are thus safer, than drivers of automatic cars (or EVs, for that matter).
If you have, please share.
Again, no one said that "manual transmission drivers had greater road awareness, and are thus safer," either. But again, I do believe that driving a car with a manual transmission increases road awareness. I'm not here to cite to "published studies," but commenting on this thread's topic about regen braking saving the OP from two accidents and relaying my personal experience.
 

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