Electric cars prove we need to rethink brake lights

Published 2023-05-25
Truly, this is a pressing issue. I hope somebody at the helm is watching.

Links 'n' stuff:
The mentioned turn signal video
   • The Senseless Amb...  

My other vehicular-lighting related content:
On how we used to require all cars to have the same headlights
   • Old car headlight...  

On why you can't get turn signals to synchronize (except now you can)
   • Why it's not poss...  

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00:00 Intro
01:47 Demonstration
03:15 Regen braking and one-pedal driving
09:17 Somebody forgot about the brake lights
12:25 One solution that GM came up with
15:12 Adaptive cruise control
16:25 US regulations
21:15 The Boy who Cried Wolf problem
21:50 Europe's previously terrible regulations and their fix
25:47 An earnest call to action
28:38 Bloops

All Comments (21)
  • It appears I should have had more faith in the land of amber turn signals! Apparently you've had a quite sensible regulation on the books since 2015. The thing that was just approved in March was a UN thing not adopted by the EU - oops! Apologies from this American, I shouldn't have doubted you. Here's the current in-force regulation:
  • @timseguine2
    As a software engineer I feel qualified to say that one man's software can also be the same man's nightmare.
  • How this guy gets me and 2 million other people to watch a 29 min video about "another brake light problem" is pure magic. 🧙
  • @lancecustar
    Honestly the accelerometer is a good idea that covers a bunch of weird scenarios that even normal vehicles and brakes don't cover.
  • @xiphosura413
    I actually quite like accelerometer-based brake lights because they react even if you are slowing down for reasons outside of your control, which I reckon is a great safety feature. Unexpected slowdowns with no brake lights sound like a great recipe for disaster, and it's neat how it automatically takes that into account. Just don't make like GM and forget the mechanism to leave the light on when stopped :p
  • @HappyBoySWE
    I actually encountered this a few days after first seeing this video. Coming off the highway behind an ionic and it was slowing down quite fast without any lights showing while I was on the brakes quite firmly. I was prepared since I was turning off with it but I can absolutely see this being an issue if someone is coming up on them faster or not paying full attention
  • @MrRedPony01
    The accelerometer in the bolt was already there for the stability control. They just had to write some extra code for the secondary function.
  • I’m an automotive lighting, safety engineer, and just shared this with my team. Keep up the good work 😇
  • @roblasala1252
    This seems like it can be easily solved with a software update. Either adapting gas pedal position threshold based on regen braking intensity mode, or GMs idea
  • @ryanwatts3168
    I’ve always wondered how often these one pedal systems communicated brake lights. Also how adaptive cruise control does it. Great video👍
  • @970357ers
    Mapping already present pedal position and G sensors to a ‘brake map’ (similar to a gas engine throttle map) could combine road speed, pedal position and G-force to determine whether to illuminate the brake light. Mandate a few key (on/off) points on that map. Job done.
  • @chounoki
    I agree with you. The brake lights should be based on the speed of deceleration only, not on whether a pedal is depressed or not.
  • I would like to add that this has been a much older problem with motorbikes; that is, leaving the bike in gear without power can significantly reduce the speed of the vehicle without having to depress the brakes (Due to wind resistance and a smaller flywheel). In training, I was asked to lightly tap the brake pedal when ever i used engine braking to signal that the vehicle was slowing down instead of relying on any software.
  • @MrMoustaffa
    This man has more passion for car signals than most people have for their marriages. Truly the hero we needed but dont deserve
  • @snowskeleton
    Reminds me of a similar issue with regards to downshifting with a manual transmission. Even if I'm engine breaking, I'll tap the break pedal (or hold it lightly) to indicate that I'm slowing down.
  • @mennims
    It would be interesting if the lights came on based on the de-acceleration speed regardless if you're pressing the brake pedal. I wonder what the pros and cons of this would be, maybe they can mix the two. Maybe the brake light can flash slowly depending on the aggressiveness of the regen
  • I had an idea many years ago to make the center high mount stop lamp be of variable size and intensity based upon amount of braking force applied. It illuminates the center of 5 segments with an initial application, expands to 3 of the 5 segments with more deceleration, and all 5 when fully applied. That tells the drivers behind you if you are just tapping your brakes, or in a full panic stop.
  • @BondiAV
    These days, brake lights controlled by an accelerometer should be mandatory on any new car (not only on electrics). It would save me (and many other people, I suppose) the trouble of worrying about how would other drivers know every time I slow down by down-shifting (which I do quite frequently). Of course, we have the option of lightly touching the brake pedal (just enough to trigger the brake lights), but if cars are indeed becoming "smarter", this would be one very useful feature to include.
  • @hugoiwata
    I love how your videos range from "I'm really bothered by this very small design issue in this very specific product" to "Many people may die because engineers are lazy"
  • @walrus4248
    This video answered a lot of questions I didn't even know about for electric cars. Good to know you can't wait for a brake light.