Brake light function with one pedal driving?

[Singletracker]

We have all had the experience of driving behind somebody that is constantly on and off their brakes. You know - the persistent tailgater, erratic on and off the gas/brakes, two foot, etc drivers. It can be annoying watching those brake lights constantly cycling, often times for no good reason. My question is - using one pedal driving, when does the vehicle activate the brake lights? Surely, this can’t happen every time one lets off the throttle a little, just to gradually slow a bit. Is there a sensor that monitors the actual rate of deceleration and then controls the brake lights accordingly? Just curious

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[SolartoEV]

Yep

 

[Dark-Fx]

It's based off of the amount of deceleration.

This is what the law is for european countries. I thought there was an identical law for the US but I can't find it currently, so ignore previous edits of mine.

I've actually observed that when you are traveling at a decent rate of speed and regen brakes are severely limited that the Rivian will still slow down but not illuminate the stop lamps, so they have to be measuring it somehow.

 

[909phillyman]

We have all had the experience of driving behind somebody that is constantly on and off their brakes. You know - the persistent tailgater, erratic on and off the gas/brakes, two foot, etc drivers. It can be annoying watching those brake lights constantly cycling, often times for no good reason. My question is - using one pedal driving, when does the vehicle activate the brake lights? Surely, this can’t happen every time one lets off the throttle a little, just to gradually slow a bit. Is there a sensor that monitors the actual rate of deceleration and then controls the brake lights accordingly? Just curious

Thank you for asking this question...I have wondered this as well.

 

[alisdair1941]

No good reason?

Foot off throttle = Regen = Slowing Down = Brake Light

It's there to warn other drivers that you are slowing down (for any reason). Imagine if the brake lights didn't come on when you were actually slowing down and you get rear-ended as a result of somebody behind you not slowing down in response to your lights not activated, especially in the dark. You'd probably be found at fault in that case.

I also get annoyed at people who use it persistently, but then maybe I'm following too close to be annoyed in the first place, which would make me the tailgater, not them...

 

[wizard467]

My question is - using one pedal driving, when does the vehicle activate the brake lights?

As others have noted it is based off of the amount of deceleration so if you only gently let up on the pedal the lights don’t always turn on.

One thing to note is once you are driving in the truck the dash display WILL show you if the brake lights are on.

 

[Singletracker]

No good reason?

Foot off throttle = Regen = Slowing Down = Brake Light

It's there to warn other drivers that you are slowing down (for any reason). Imagine if the brake lights didn't come on when you were actually slowing down and you get rear-ended as a result of somebody behind you not slowing down in response to your lights not activated, especially in the dark. You'd probably be found at fault in that case.

I also get annoyed at people who use it persistently, but then maybe I'm following too close to be annoyed in the first place, which would make me the tailgater, not them...

Well, with my ICE vehicle, I slow down countless times during a given drive. Each minor let off the gas slow down, doesn’t necessitate using the brakes. Ideally, there is a smooth ebb and flow to traffic. It would be crazy if every time I took my foot off the gas a little, the brake lights came on. Heck, other drivers would never know whether that brake light actually meant a stop or just a coast. Ever hear that story of the boy who cried wolf For tailgaters, there is no smooth ebb and flow, as there is no cushion between vehicles. It’s always on the gas or on the brakes.

I’m going to have to pay more attention the next time I’m behind an EV, see how often and when the brake lights activate.

 

[freshpow]

As others have noted it is based off of the amount of deceleration so if you only gently let up on the pedal the lights don’t always turn on.

One thing to note is once you are driving in the truck the dash display WILL show you if the brake lights are on.

I've only had my truck for a few days and did not pick up on that. Thanks for sharing!

 

[SANZC02]

Thank you for asking this question...I have wondered this as well.

There are regulations that dictate this action. Additionally if you look at the vehicle in the drivers screen it lights up to tell you when the brake lights are triggered. Not as noticeable as the Tesla Model S display but it is still there.

 

[Singletracker]

One thing to note is once you are driving in the truck the dash display WILL show you if the brake lights are on.

Interesting. Did not know that. Good to know. Thanks

 

[alisdair1941]

Well, with my ICE vehicle, I slow down countless times during a given drive. Each minor let off the gas slow down, doesn’t necessitate using the brakes. Ideally, there is a smooth ebb and flow to traffic. It would be crazy if every time I took my foot off the gas a little, the brake lights came on. Heck, other drivers would never know whether that brake light actually meant a stop or just a coast. Ever hear that story of the boy who cried wolf For tailgaters, there is no smooth ebb and flow, as there is no cushion between vehicles. It’s always on the gas or on the brakes.

I’m going to have to pay more attention the next time I’m behind an EV, see how often and when the brake lights activate.

The point I was trying to make is that, regardless of it coming on or not, it's not your responsibility to be paying attention to your own brake light. Your eyes should be on the road in front of you (being mindful of surroundings as well of course). If somebody behind you is annoyed with how frequent your brake lights come on, that's on them. If you're driving normally then don't worry about it.

As long as they are working at all is what I would be concerned with.

 

[ironpig]

Go to page 93 of your R1T manual - https://assets.rivian.com/2md5qhoea...05dfa95a4e059ba4251/r1t-og-en-us-20230327.pdf

All EVs activate the brake lights under regenerative braking although I'm not sure if it's only at certain speeds. You can see them illuminate as you approach a stop sign with no pressure on either pedal.

 

[Jayhawkeye]

Your driver display will illuminate the brake lights if you want to test it out.

 

[cohall]

As posted above, it only comes on when certain deceleration thresholds are exceeded. It's definitely not every time you lift of the accelerator. That would be crazy.

Easiest way to see when they're coming on is to drive at night with the crossbars installed in the bed. They reflect the cyclops light into your rearview mirror. If you're gently slowing down it definitely does not come on until you're almost to a stop.

 

[JohnB R1T]

There have been really good reasons NOT to tailgate since the second automobile hit the road. It used to be, that everything had a manual transmission. Some still are.

It used to be the "normal" way to drive was to upshift to continue accelerating and then downshift to slow down. No amount of downshifting ever activated a tail light. People actually had to pay attention to the vehicle that was in front of them.

Nowdays, we have metric sh*t tons of drivers who have no idea what to do with a clutch and stick shift. Most people no longer "drive"...they just "aim"....[end of rant.]

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