Brake Lights on Deceleration

[PoweRWatt]

Has anyone else noticed that deceleration no longer causes the brake lights to turn on? It appears that I have to take my foot completely off the accelerator to get the brake lights to function.

Just me or is this not a pretty visible safety issue given how many people text & drive. No brake lights until last second could easy result in being rear ended on High regen.

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[Mathme]

The dash screen on both my truck and my current R1T loaner show brake lights once there's an appropriate amount to stopping power being added. Both are set to high regen.

 

[mudito]

The dash screen on both my truck and my current R1T loaner show brake lights once there's an appropriate amount to stopping power being added. Both are set to high regen.

Same here, I had my bed full of tires yesterday and I was getting the reflection of the red-braking light very prominently shining in my cabin

 

[mkg3]

I cannot recall the exact deceleration rate but there is a NHTSA regulation that require regen braking to initiate brake lights if its slowing down more than the specified rate.

 

[VandalSibs]

mkg3 is on the right track.

If you are feathering the accelerator pedal enough when slowing down, the brake lights won't trigger because you never reach the rate of deceleration that sets off the lights. Either come off the pedal faster, or outright just lift your foot off so that you get full regen ASAP and the lights should come on just fine.

 

[Nixapatfan]

Yes I wish they came on at a lower threshold, sometimes I can come to nearly a full stop without the brake lights coming on. As others have said just need to deliberately force it to come on by harder regen.

 

[southerncadesi]

I'm with OP on this one, I only do one pedal driving and feather it from stoplight to stoplight so that I'm not deaccelerating too fast to where it causes jerkiness. But the drawback here is traffic behind me may not understand/pay attention that I'm slowing down and could case a rear-end accident.

I think the deacceleration rate in which the brake lights turn on should be lessened so that the brake lights come on more frequently.

 

[Dark-Fx]

Decelerate faster, or hit the brake pedal. The rate at which you are slowing down isn't enough to warrant brake lights. If your lights were on already, and you suddenly realized you need to brake much harder, the folks behind you might not notice immediately, because there is no transition on the lights.

 

[VandalSibs]

I'm with OP on this one, I only do one pedal driving and feather it from stoplight to stoplight so that I'm not deaccelerating too fast to where it causes jerkiness. But the drawback here is traffic behind me may not understand/pay attention that I'm slowing down and could case a rear-end accident.

I think the deacceleration rate in which the brake lights turn on should be lessened so that the brake lights come on more frequently.

There are times that I agree, but in the end if someone is following you too closely and crashes into you, that's their fault. Keeping proper following distance is part of being a responsible driver and that's not your responsibility (for the cars behind you, anyway).

 

[mkg3]

Yes I wish they came on at a lower threshold, sometimes I can come to nearly a full stop without the brake lights coming on. As others have said just need to deliberately force it to come on by harder regen.

Check your regen setting. I often use Low Regen and when doing so, the brake lights do not come on unless I tough the brake pedal. When coasting, albeit gradually decelerating, its not slowing down quickly enough to trigger the brake lights and is regen braking slower than the regulation.

 

[southerncadesi]

There are times that I agree, but in the end if someone is following you too closely and crashes into you, that's their fault. Keeping proper following distance is part of being a responsible driver and that's not your responsibility (for the cars behind you, anyway).

Totally understand it's on the drivers behind me to drive responsibly and pay attention. But in the age where everyone is texting, phones on their laps, folks not having insurance, etc. I've just become more and more paranoid of being rear ended.

On my other car (ICE) I added a brake light flasher where when I tap the breaks the middle light flashes a couple times to grab the attention of the drivers behind me.

A slight tweak, maybe 1 m/s less (guessing here) than where the current brake light deacceleration rate is at is all I'm asking for

 

[VandalSibs]

Totally understand it's on the drivers behind me to drive responsibly and pay attention. But in the age where everyone is texting, phones on their laps, folks not having insurance, etc. I've just become more and more paranoid of being rear ended.

On my other car (ICE) I added a brake light flasher where when I tap the breaks the middle light flashes a couple times to grab the attention of the drivers behind me.

A slight tweak, maybe 1 m/s less (guessing here) than where the current brake light deacceleration rate is at is all I'm asking for

I'm in the same boat - so many people following too closely...

My wife likes to pop on the backup cam and get angry about those that are too close (to see if she can read their plates or not....)

 

[csharp]

Feathering the accelerator and slowing your vehicle down but not enough to trigger the brake lights is the equivalent of you removing your foot from the accelerator in an ICE car and coasting. No brake lights come on when you coast, but you are slowing at the same rate as if you feathered the accelerator off on an EV.

 

[usulio]

Sensitivity of brake lights has been discussed, here’s one: https://www.rivianforums.com/forum/...ize-crew-cab-truck-vs-rivian-r1s-wreck.45730/

Feathering the accelerator and slowing your vehicle down but not enough to trigger the brake lights is the equivalent of you removing your foot from the accelerator in an ICE car and coasting. No brake lights come on when you coast, but you are slowing at the same rate as if you feathered the accelerator off on an EV.

That’s not precise. In one-pedal drive EVs you can lift off and get light regenerative braking where the vehicle is being braked, but the brake lights don’t come on unless it’s above a certain level. The question is if rivian sets the level correctly and if it possibly varies between vehicles because people report different things.

 

[mkg3]

From Perplexity:

When an electric vehicle (EV) uses regenerative braking, the rate of deceleration determines whether the brake lights are triggered:

• Brake lights must activate when the vehicle decelerates at or above 1.3m/s² (about 4.27ft/s² or 0.13g) during regenerative braking.

• For deceleration rates between 0.7m/s² and 1.3m/s², activation of brake lights is typically at the manufacturer’s discretion—some vehicles will illuminate while others may not.

• Below 0.7m/s², brake lights generally do not illuminate during regenerative braking.

These thresholds are used in both industry practice and regulations...

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