Have you been rear-ended using 1PD?

[Jbkimmel]

I was using 1 pedal driving in stop and go on the freeway the other day and had a guy behind me make a hard stop to avoid hitting me. It’s totally possible that he would have almost hit me even if I were using conventional braking - with brake lights on. But it got me wondering whether there is some level of safety “risk” with 1PD, and what those of you with more than a month of MME ownership think. And whether any of you have adjusted your 1PD use accordingly.

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[Kevin P]

1PD activates the brake lights at anything above very mild decel. You can see them at night. I think it MIGHT be 0.2g but not certain.

 

[JamieGeek]

Nope: Been using 1PD for 4 years now (Bolt had 1PD) no issues.

Unlike driving a stick and using 1st gear to slow down 1PD does turn on the brake lights (as Kevin notes above).

Once stopped it keeps the lights on until you hit the go pedal.

 

[mikeinet]

I’ve monitored this at night- I find you do start slowing before the brake lights come on, but when you let up about half way off the pedal the lights absolutely come on

 

[The Electric Duo]

I have been rear ended when I was using 1PD... but I was at a complete standstill and the guy was just an idiot. But after that, I've tried to take notice of how sensitive the brake lights are to deceleration when using 1PD. It can be hard to tell but I've tested on some dark roads and I feel confident that they do come on with even mild slowing using 1PD.

Note: Getting rear ended at a standstill using 1PD made me realize I needed to develop the habit of resting my foot on the brake when stopped even though the car does Autohold. At the time I was rear ended, my foot was on the brake and I mashed the pedal hard and still barely missed hitting the guy in front of me. If my foot hadn't been on the brake, I'm not sure that would have been the case. And if my foot had been on/near the accelerator, that could have been disastrous.

 

[Jbkimmel]

Gee, maybe I should have started by asking whether the brake lights come on with 1PD… ?
I’ll stipulate that this thread was based on a faulty premise but still appreciate the input - including Patrick’s anecdote above. Thanks!

 

[Old Guy]

I took over a 6.26.21 2021 order and gave up a 2022 order made on 10.1 thinking I could get it earlier. It’s been in production since 12.14 with off and on the factory floor. The original delivery date was 12.21, then 2.16 and now 4.20. There is a sense of absurdity here.They’re really planning to deliver me a 2021 in April of 2022? Perhaps I should order the Lexus I originally planned on getting.

 

[ARK]

I don’t use 1PD, but I feel you probably put yourself at a higher chance of being rear ended if it’s making you slow down differently than you would in an ICE or with 1PD off, because then you are surprising other drivers.

Like if you start to slow down more abruptly because you are fully lifting off the pedal (and therefore applying max regen all at once) instead of feathering it by slowly lifting off the way you would slowly start pressing the the brakes (when 1PD is off) and get on the brakes harder as you get to the traffic light, stop sign, stopped traffic, etc.

If your slow down pattern is different with 1PD, I think it makes it more likely another driver would miscalculate and hit you.

I think it’s similar with adaptive cruise control with four car length distance set in stop and go traffic. There is an expectation that a driver will fully or almost fully close the gap with the car in front in a ‘stop’ cycle. But when the adaptive cruise control abruptly stops your car four car lengths from the guy in front of you in what is otherwise bumper to bumper traffic, you end up surprising the person who is himself behind you, making it more likely you get hit.

So, moral of the story, whether you use or don’t use 1PD a big part of not getting rear ended IMO involves not surprising the guy behind you with an abrupt or unexpected maneuver.

 

[MachEZRt1]

I’m happy with the sensitivity of the brake lights coming on when lifting off the accelerator in 1PD. This is one of the first things I tested when I got my MME at night with a similar concern. I think I had a higher chance getting rear ended in my second gen Volt driving in L as this was a way of increasing regen and getting closer to 1PD without similar sensitivity of the brake lights coming on while releasing the accelerator.

 

[phidauex]

I did a little testing of the brake light turn-on in 1PD, and it is very sensitive. I'd say they turn on even quicker than if I were in an ICE vehicle and just engine braking a bit to slow. I measured the turn-on to happen around 0.02gs, which is quite gradual.

It almost made me self conscious a bit while descending canyons around here. The "conventional wisdom" in the mountains is that if you hit your brakes all the time you are a newbie - experienced mountain drivers manage their speed using gear selection only (this mattered back in the day when burning up your brakes was a very real possibility).

So having 1PD flashing my brake lights all the time made me worry about my reputation (just for a moment, until I realized that was silly). The car is actually one step better than engine braking, it is recovering all that free energy!

 

[Jbkimmel]

I know what you mean - I think many of us roll our eyes a bit at folks riding their brakes. Ah, humility. Unless we all get bumper stickers telling the world that we’re not using our brakes…and regenerating! ?

 

[ponydsp]

I know what you mean - I think many of us roll our eyes a bit at folks riding their brakes. Ah, humility. Unless we all get bumper stickers telling the world that we’re not using our brakes…and regenerating! ?

Or we should petition EVs to have a separate blue brake lights to let everyone know these cars are regening.

 

[generaltso]

I took over a 6.26.21 2021 order and gave up a 2022 order made on 10.1 thinking I could get it earlier. It’s been in production since 12.14 with off and on the factory floor. The original delivery date was 12.21, then 2.16 and now 4.20. There is a sense of absurdity here.They’re really planning to deliver me a 2021 in April of 2022? Perhaps I should order the Lexus I originally planned on getting.

And this led to getting rear-ended?

 

[rzanzerkia]

I have been rear ended when I was using 1PD... but I was at a complete standstill and the guy was just an idiot. But after that, I've tried to take notice of how sensitive the brake lights are to deceleration when using 1PD. It can be hard to tell but I've tested on some dark roads and I feel confident that they do come on with even mild slowing using 1PD.

Note: Getting rear ended at a standstill using 1PD made me realize I needed to develop the habit of resting my foot on the brake when stopped even though the car does Autohold. At the time I was rear ended, my foot was on the brake and I mashed the pedal hard and still barely missed hitting the guy in front of me. If my foot hadn't been on the brake, I'm not sure that would have been the case. And if my foot had been on/near the accelerator, that could have been disastrous.

This is exactly the scenario my wife asked me about.
What happens if the foot is near accelerator and someone rear ends you.
I am wondering if car has any crash sensors that would disable acceleration in an accident?

 

[DevSecOps]

Or we should petition EVs to have a separate blue brake lights to let everyone know these cars are regening.

How about ... no?

@ARK hit the nail on the head. The cause of many accidents is because of people doing things that are out of our expected range of events. This is actually one of the main reasons behind self-driving accidents and the concern behind them. It's also why Tesla phantom braking is a very serious issue as well. Unexpected lane changes is the 3rd leading cause to fatal accidents and unexpected maneuvering is 10th. When groups of people drive different many people often label the entire group as "bad drivers" (aka stereotype).

Unless the MME starts suffering the same fate as Tesla I don't think it falls much within the unexpected when it comes to 1PD braking. For ACC/BC I would agree that the stopping is mildly more aggressive than an average human and if the person behind is following closely could result in a rear ending.

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