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Electric cars prove we need to rethink brake lights
- twobitshifter 3y agoThis isn’t really a new problem. You could engine brake your manual transmission car without touching the brakes and there’s such a thing as going uphill. I think the bolt solution of an accelerometer gives the best indication that a car is slowing down quickly.
- consp 3y agoIt's a US problem probably, everywhere manual transmission was or is a thing everybody expects cars to slow down. Also: keep enough distance, pay attention and this is never an issue.
- roomey 3y agoWell yes, but engine breaking is a lot weaker then regen braking can be, so there really needs to be break lights id deceleration is more than one would reasonably expect engine breaking to achieve
- cataphract 3y agoReally depends on the car. There are cars with very little inertia, if you let go of the gas pedal quickly they will get quite jerky. In those, you really have to depress the clutch before completely letting go of the accelerator.
- Enerccio 3y agoWhat kind of a car is that? I have 1.6l hyndai ix20 and I can let off gas at any time with zero issues....
- willio58 3y ago> keep enough distance, pay attention and this is never an issue If this was helpful, far fewer crashes would happen on roads today. People are imperfect. They're distracted, they have slow reaction times, they have poor vision, and they drive in poor weather. As the video states, regulations should definitely be altered to require car manufacturers to show brake lights no matter how deceleration occurs. It's just one additional way to prevent collisions.
- deleted 3y ago[deleted]
- spookthesunset 3y ago> keep enough distance, pay attention and this is never an issue That isn’t how safety regulations work. Driving is a cooperative affair and giving more information about your intend to the drivers around you is a good thing. I mean if all it took was “keep distance and pay attention” why bother with turn signals? And as a side note: “self driving” cars still haven’t completely figured out the right algorithm for turn signals. I watch enough “AI Driver” on YouTube to see him call out how Tesla’s turn signaling is sometimes pretty erratic. It is probably a pretty hard problem when you think about it. Showing brake lights is much easier. Got a deceleration over a certain value? Well, show them lights!
- mynameisvlad 3y ago> I mean if all it took was “keep distance and pay attention” why bother with turn signals? Have you met BMW drivers? /s You should be practicing defensive driving whenever you drive. It's what's taught nowadays and has been for a long while. You should expect others to be driving at their worst. No turn signals, broken tail lights, erratic lane change, abrupt braking or acceleration, the whole shebang. Expecting the worst is the best way to ensure your own safety on the road.
- SuperNinKenDo 3y agoI laughed at the mention of BMW drivers because it's so spot on. I agree that defensive driving is always the way to go, but at a certain point you need information. TC essentially goes from 100km/h to stopped in less than 15 seconds without any obvious visual indication. That's coming to the point where there's almost no defensive driving possible and a deadly highway collision becomes more likely than not. It's the same in any situation. Always assume people will do completely insane things and prepare accordingly, but that doesn't mean we should make things more dangerous for no good reason. For all the truth that more chaotic roads make for more attentive drivers, they also still make for more accidents.
- NikolaNovak 3y agoYes. But the point is more information is good. You can be the most observant most defensively best trained driver, and more predictable information is still good. I don't understand the motivation of arguing an objectively provably demonstrably good thing, because some other thing is also good :-).
- ilyt 3y agoKeep enoug distance to be safe and someone will just change a lane to be in front of you, removing any safe distance you decided to keep
- p1mrx 3y agoThen slow down a bit and make more space. Traffic flows better when people have room to change lanes.
- ilyt 3y agoThat's my complaint, if I do someone just fills that space because their lane is going 2cm/minute slower than mine
- p1mrx 3y agoThen slow down a bit and make more space. There's no trophy at the end.
- ilyt 3y agoWhich causes next car to get in front. Still no space, nor more safety, and also triggering morons to do extra maneuvers and potentially fuck up more. Do you lack ability to think about the results of the actions ?
- HPsquared 3y agoIn theory you can, but 99% of the time you'd still generally use the brakes for any serious deceleration. On the other hand with one pedal driving, regen braking is used 99% of the time.
- tmerc 3y agoI've thought about putting a manual brake light switch in my manual transmission car because of this, but I'm also that guy that engine brakes more than actual brakes. 6 years of owning this car and I've never worn out a brake pad.
- OkayPhysicist 3y agoWouldn't it be easier to just put some light pressure on your break pedal while you're engine breaking? My older Acura definitely lights up the break lights well before actually engaging the brakes.
- tmerc 3y agoMuch easier, but not as technically interesting :) And I do pedal it if I think the driver behind me is risky, though I'm not sure where the light engagement is relative to brake engagement.
- interestica 3y agoThat foot is on the gas pedal still in a lot of cases
- stanski 3y agoIt's so nice to not have to ride your brakes going downhill, especially when you also have to turn at the same time. (I miss my old manual car)
- tmerc 3y agoNewer manuals are really nice.. mine has hill hold, which some people hate but I enjoy. And supposedly engine braking uses no fuel.
- function_seven 3y agoUnless you have an older carbureted vehicle, engine braking should use no fuel: https://en.wikipedia.org/wiki/Engine_braking#Limitations https://en.wikipedia.org/wiki/Engine_braking#Limitations Just do a decent job matching revs on the downshifts so you don't trade brake dust for clutch dust :)
- Gordonjcp 3y agoWhy would you need an accelerometer when you've got perfectly good tacho pulses from the ABS rings?
- mindslight 3y agoAFAIK ABS modules already have accelerometers. If I had to guess it falls into the domain of the ABS module, and it's just easier to talk about it as an accelerometer, when it's really using multiple inputs (wheel speed sensors can fail). I hope whatever new regulation is intelligent enough to not consider the deceleration from coasting up a hill to be part of triggering the brake lights. Brake lights should only come on when there is deceleration beyond what you'd expect from a naturally rolling car.
- Gordonjcp 3y agoOne would assume it's not a difficult process to model. If the driver presses the brake, put the brake lights on. If the driver lifts off the throttle in heavy regen mode and the vehicle slows faster than <some amount> put the brake light on. If the vehicle slows faster than <some amount> with the throttle "off idle", do not put the brake light on.
- Pxtl 3y agoGoing uphill isnt a problem because the car behind you is also going uphill. The point of brake lights is to warn driver's behind you they need to brake, which is why it needs to be a measure of negative force being applied by the car, not just the resultant acceleration vector.
- bearjaws 3y agoNoticed this the other day when behind an Ioniq, I knew immediately it was because of regen braking. I love Technology Connections for taking it a layer deeper and going into the regulations and industry experts.
- influxmoment 3y agoSounds like an Ioniq specific oversight and bad design not a general problem with break lights
- Pxtl 3y agoIf you watch the vid, he starts out with the Ioniq's problem but then goes into discuss how their implementation actually meets the regs and therefore the regs are bad.
- mfalcao 3y agoJust watched this while eating. It's half an hour long, so here's a summary: - He owns a 2022 Hyundai ioniq 5, USA version - The brake lights generally work fine, however when in one-pedal mode (i.e. accelerator does regenerative braking for the first X% of travel) they only activate when the vehicle is about to stop so long as the driver has the accelerator ever slightly depressed - This is a problem because the regenerative braking is quite strong - he goes from 60 mph/96 kph to 0 in 13 seconds and the stop lights never illuminate - He thinks this should not be allowed and Hyundai should recall the cars to fix this - However, in the US this is perfectly legal - regenerative braking is not considered as part of the "service brake", so illuminating the stop lights is not required - The EU on the other hand just fixed this gap in the law in March, by requiring that stop lights be illuminated whenever the deceleration exceeds 1.3 m/s^2
- nabla9 3y agoExhaust brakes on truck or engine braking behaves the same way. There can be strong deceleration without brake lights. Deceleration threshold is great solution because it signal what is happening.
- bryanlarsen 3y agoTrucks use exhaust braking because it's quicker than braking using the brakes without overheating. They can get away without brake lights only because the noise makes it obvious when trucks are exhaust or engine braking.
- rcme 3y agoEngine breaking, which any manually car driver uses, does not produce any indication that you're slowing down. Technically, the engine noise is louder, but not enough to notice outside of the car.
- tmerc 3y agoYou can engine brake in any "manumatic" like Subaru with their flappy paddle CVT. You could drive a manual without engine braking more than a normal automatic; nothing forces you to downshift. You could also only up shift and use neutral when braking with actual brakes, which I think a lot of people do when learning manual. Indications that the car in front of you is breaking include brake lights, distance between you and them, and weight transfer to the front (nose down, rear up). Only one of those is affected by the thick pedal.
- phkahler 3y agoRegenerative braking should trigger brake lights if it's strong enough. The car knows your brake pressure and it knows how much regen torque it's applying. Just sum those two and turn on the light at the same threshold as before. OTOH there may be a federal regulation that doesn't permit that. I haven't studied FMVSS in a while.
- willio58 3y agoDid you watch the video? Because that's exactly what he says. The whole issue boils down to the fact that the regulations are outdated, not that there are conflicting regulations.
- rootusrootus 3y agoWorth noting is that even if the regulations could be worded better, nothing is stopping Hyundai from doing it correctly. It's not forbidden by regulation, most other manufacturers get it right.
- brewdad 3y agoWhile they have these cars in the shop for the theft related recall* they should update the computer to fix the brake lights too. *I have no idea if this specific car is recalled.
- rootusrootus 3y ago> *I have no idea if this specific car is recalled. No, the only affected cars were ones that used a traditional key. Not the push-button cars, which necessarily excludes all their EVs as well.
- willio58 3y agoRegulations are there to help in cases like this. If the regulation is failing to accommodate modern vehicles, they need to be changed. Trusting companies to "get it right" on their own and act in the best interest of peoples' safety leads to unnecessary deaths. Seriously, back when seatbelts were invented car manufacturers were almost completely against it. They lobbied against regulations to implement them. Luckily, at the very end of the video, it's actually revealed that a couple of months ago the new regulations were put into action (about a decade late)
- elil17 3y agoI have been driving my hybrid under the assumption that my brake lights triggered when ever the car used regenerative braking. Guess I will have to be more careful.
- rootusrootus 3y agoIf you're not driving a Hyundai, it's probably working as you expect.
- elil17 3y agoI'm driving a Honda. I looked it up and people online say that it has the same issue. However, I plan to observe for myself.
- brewdad 3y agoNow I'm curious about my Volvo. I do most of my freeway driving with the adaptive cruise control adjusting my speed to match the flow of traffic. I have no idea if my brake lights are triggering when the ACC slows my vehicle due to a slower car in front of me. I certainly am not touching the brake, unless I need to stop more quickly. Given Volvo's reputation for safety, I'm assuming they got it right but that is purely assumption on my part.
- rootusrootus 3y agoMy guess is that most decent TACC implementations won't activate the brake lights when slowing for a car in front, unless that car cuts you off. Generally the deceleration should be slow enough that it falls under 'engine braking' levels and therefore unworthy of a brake light.
- elil17 3y agoUpdate: My Honda does not show brakelights until I hit the brake peddle, even on the highest regenerative breaking setting.
- 3y ago
- renewiltord 3y agoI'd like to show people behind my accelerator / brake / clutch state. Would be cool if they had the information so they could react appropriately.
- Sohcahtoa82 3y agoClutch state would be lost on at least 95% of drivers in the USA. Honestly, I'd wager that half the people driving a manual car that's not in a sports car doesn't even know what the clutch is actually doing. They just know they need to press it while shifting and hold it halfway out for a second or two when coming from a stop with no concept on why they have to do that, other than "That's what you do in a manual transmission".
- ilyt 3y agoOr just huge bargraph at back showing acceleration/deceleration of the car.
- renewiltord 3y agoYeah, I was thinking of that. Sounds like it would be neat. I wonder if it is legal.
- twobitshifter 3y agoI have seen some cars that have pulsing brake lights to indicate aggressive braking. Don’t know if this was aftermarket or not.
- b0sk 3y agoI think Tesla solved this problem. https://www.tesla.com/ownersmanual/modely/en_eu/GUID-3DFFB071-C0F6-474D-8A45-17BE1A006365.html https://www.tesla.com/ownersmanual/modely/en_eu/GUID-3DFFB07... "Note If regenerative braking is aggressively slowing Model Y (such as when your foot is completely off the accelerator pedal at highway speeds), the brake lights turn on to alert others that you are slowing down."
- HPsquared 3y agoWhat do other manufacturers do?
- reubenswartz 3y agoSeems like a software problem that they will hopefully fix. Teslas do this already.
- bwanab 3y agoFrom Tesla (note this is for the Model Y, but is true for all models): --------------- If regenerative braking is aggressively slowing Model Y (such as when your foot is completely off the accelerator pedal at highway speeds), the brake lights turn on to alert others that you are slowing down. --------------- I had kind of assumed all electric cars did that, but I guess not.
- jwr 3y agoMy VW ID.4 does this correctly: the brake lights come on whenever the car slows down, which could be because I pressed the brake pedal or because I released the accelerator pedal in "B" mode. The software on this car sucks really badly in too many ways to describe here, but this part they got right.
- geephroh 3y agoThanks for posting! I was just thinking about how I was going to confirm this on mine. And, yeah, the software is hot garbage.
- rootusrootus 3y agoSolved problem. My Teslas have always activated brake lights based on deceleration. My wife's Bolt does as well, though it does have a glitch -- once it comes to a complete stop, it turns off the brake lights if you don't have your foot on the brake. Tesla gets it right, keeps the brake lights on until you start to move again.
- _whiteCaps_ 3y agoThat's covered in the video - GM uses an accelerometer to detect braking. Once you stop decelerating, it turns off.
- hedora 3y agoGMs now incorrectly turn the backup lights on when in park. Bastards.
- londons_explore 3y agoThis is part of a larger class of problems, which is "car manufacturers are not taking some quite simple steps to make the roads safer". I think this could be solved with a small fee, payable by a vehicle manufacturer, whenever one of their vehicles is involved in a road traffic incident. Perhaps $100 would be enough for them to keep an eye on their fleet of cars on the road, and do basic things to minimize accidents, like for example tyre wear alerts.
- londons_explore 3y agoBilling a company for something that is entirely outside their control (post sale) isn't going to fly. But you could maybe publish safety figures per manufacturer on the road, and make the scores for a new car incorporates the manufacturer score too - therefore effectively giving a competitive advantage to manufacturers that make cars which turn out to be safe.
- ilyt 3y agoThat has added advantage of preferring cars that are actually safer and not cars that filled some safety checkbox.
- bryanlarsen 3y agoTesla is now in the insurance business. So it has a direct incentive to prevent crashes, as well as to make the car cheaper to repair.
- londons_explore 3y agoThey also have the reverse incentive if their cars get into crashes which are other people's fault. They get to profit from very expensive repairs, paid by the other guys insurance. Making sure the brake lights work more effectively than the regulations require, reducing rear-endings of tesla customers, would then reduce profits...
- asynchronous 3y agoNo, Hyundai needs to rethink how brake lights work. Putting yet another mark on the board for things Tesla engineers figured out nearly a decade ago that other car companies haven’t.
- helf 3y agoEventually they will figure out things like properly gapped body panels and not removing hardware functionality at servicings!
- mikestew 3y agoNissan figured it out in the original '11 Leaf before the first Model S was even delivered. Other companies have figured it out as well, it would seem Hyundai just dropped the ball on their design.
- diebeforei485 3y ago> before the first Model S was even delivered The original Roadster came out in 2008.
- pseudalopex 3y agoThe point was regulations should be updated. And comments said other manufacturers got it wrong.
- jeffbee 3y agoWow I actually drive a Bolt pretty often in a shared EV fleet and I always wondered what the hell the "L" on the shifter was supposed to mean. The biggest issue with the brakes on the Bolt is the way the brake pedal software works. In every other car I have ever driven, a steady pressure on the brake pedal will bring the car to a halt. But on the Bolt a steady pressure on the brake produces (inexplicably) proportionally less braking as speed falls, meaning to bring the car to a normal stop you need progressively more force on the pedal. It makes the car feel as if its brake lines are full of air, even though it's all computer-controlled regenerative braking and the hydraulic system only engages at the very last moment.
- guenthert 3y agoRegenerative braking is disabled at very low speeds as it becomes inefficient/ineffective. That's when the mechanical brakes need to be applied. Some cars might need a bit more pressure on the brake pedal for such. In a Prius (2nd gen.) this transition is barely noticeable (and I assume was the reason for some of those "sudden acceleration" claims years ago). This all applies of course only to the soft-braking when coming to a stand-still. When braking hard, the mechanical brakes are applied at high speed as well.
- milliams 3y agoI previously posted this at https://news.ycombinator.com/item?id=36071933 https://news.ycombinator.com/item?id=36071933 I'm not sure why it didn't deduplicate.
- ihuman 3y agoThat submission is marked as [dead]
- mikestew 3y agoI would argue that, no, it's Hyundai that needs to rethink brake lights (though I suppose we might write some regulations to ensure consistency). I have an Ioniq 5, and this is one of the two reasons I don't use one-pedal driving (the other is that the car always uses both motors in one-pedal mode, therefore reducing range). There are many discussions on https://www.ioniqforum.com https://www.ioniqforum.com about the subject. There are also three levels of regeneration, and apparently the highest level (Level 3) also does not light the brake lights appropriately, whereas Level 2/1 and "auto regeneration" apparently do.
- pseudalopex 3y agoComments said other manufacturers got it wrong also.
- kileywm 3y agoWhile brake lights are a fine and necessary signal, I find myself wishing that cars would display speed & acceleration deltas compared to the vehicle in front. Brake lights do not convey how much deceleration is occurring, so it's not immediately obvious how much time there is to impact. As an example, I see lots of drivers do minor braking on US highways, where their small braking corrections will cause their tail lights to flash for a brief moment. These minor corrections become noise that drowns out the signal of significant, safety-related braking. If my vehicle could warn me that their rate of deceleration puts our vehicles on a collision course... now that would be very useful.
- archi42 3y agoSome do: In ACC mode my 2013 Volvo uses radar to "lock" on the car in front of me. If it is slower than the ACC set point, its speed is indicated in the instrument panel. It looks like this: https://www.motoreport.de/wp-content/uploads/2014/01/IMG_2964.jpg https://www.motoreport.de/wp-content/uploads/2014/01/IMG_296... Set point is 110 km/h (green marker), the car in front is going 80 km/h (solid white line indicates the speed difference). The small red triangle indicates the speed limit of 80 km/h. Obviously the ACC is also cruising at 80 km/h, so most indicators are focused there. And you're right, even with the limited form (single car in front of me on the same lane, data only shown if slower) this is amazing.
- philjohn 3y agoThis was seen as a problem in Formula 1 when they moved to hybrid engines - and so when a Formula 1 car is engaging regen during braking for a corner the red light they have on the back of the car flashes to let any car following know that they are likely to stop faster than if just using brakes alone.
- 2-718-281-828 3y agofun fact: break lights are red because red light disperses / scatters less than other parts of the spectrum like yellow or green f.x. and the sky is blue because blue light disperses the most - so everything blue in the sun's light gets dispersed into the sky while the color of the sun is what's left of its full spectrum minus blue.
- gnicholas 3y agoDoes anyone know how this works in Ford EVs/hybrids? I have a PHEV CMAX and have wondered about this. I've never had an issue with people honking or getting close to rear-ending me, so I assume the lights do come on when it's decelerating rapidly.
- kotaKat 3y agoFusion Hybrid '18 here -- no brake lights on regen activity, just the dash icon that you can enable to see that it's regenning. It's not harsh regen at least on the full hybrid (even in Eco w/ Grade Assist enabled) until you slap it in low for engine braking.
- gnicholas 3y agoI drive in L almost all the time.
- diebeforei485 3y agoHow does one make a video about "electric cars" without considering that the most popular electric car brand by far (Tesla) has solved this issue years ago? There are more Teslas on the roads in the US than all other electric cars combined.
- deely3 3y agoAuthor mentioned that other car manufactures solved this issue. No need to mention Tesla specifically.
- guenthert 3y agoFor motorcycles (with combustion engines) where engine-braking can be quite effective due to the high displacement/weight ratio, there exist (but afaik isn't widely known or deployed) custom brake-light switches which can additionally be activated by chopping the throttle or downshifting. I never had such device and relied a lot on engine braking (and on followers to pay attention to the distance, rather than my brake lights). Every once in a while I surprised a tail-gater, but luckily none hit me yet. I rather think we need to rethink driver education.
- rjmunro 3y agoAre there statistics anywhere on which cars are most likely to be run into the back of? I'm sure insurance companies would be able to collate the data. It would be interesting to see how much of an effect this has.
- Animats 3y agoSelf-driving cars should flash their brake lights when they are entering an intersection with the intent of getting a view around obstructions before advancing further. That, according to California DMV reports, is when they get rear-ended. (They don't seem to get hit by cross traffic, so they're doing it right.)
- 1letterunixname 3y agoCorvair, Pinto, Suzuki Samurai, seatbelts, head restraints, offset crash testing: Safety regulations are written in blood. Only when enough people have died from manufacturers skirting technicalities will anything change.
- 1letterunixname 3y agoRelated tangent: Lemon law lawyer on Youtube: https://www.youtube.com/c/stevelehto https://www.youtube.com/c/stevelehto
- Brian_K_White 3y agoPeople have been decelerating without brakes or brake lights forever with manual transmissions. It would have definitely been unreasonable to require some kind of accellerometer system just for that in the 50s, but it's probably not asking too much today and probably more justifiably neccessary with one-pedal mode.
- deleted 3y ago[deleted]
- mulmen 3y agoI am in the middle (south of SF tonight) of a road trip from Palm Springs to Seattle in an electric campervan. This is my first EV experience and the regenerative braking is very strong. I immediately considered the brake light issue and I’m not sure what to even do. Applying the service brake seems wasteful, I have limited range and want as much regen as possible. This should definitely be addressed. Brake light activation should be based on deceleration, not pedal engagement.