Ok i’ll bite. Because why? How can you decelrate quickly enough to need to notify the driver behind you without braking?
EVs have regenerative braking, where when you let off the accelerator, it immediately starts slowing down, quickly. But the brake lights don’t come on. This would make driving behind EVs safer.
Perhaps when EVs use regenerative braking, they should display their brake lights. Use brakes, show brake lights, same rule as before just enforce it.
Perhaps when EVs use regenerative braking, they should display their brake lights. Use brakes, show brake lights, same rule as before just enforce it.
Agreed.
Old auto trannys didn’t have a bypass. You dropped to first some obeyed
Engine or regenerative braking can very quickly slow down a vehicle but may not activate the brake lights depending on the manufacturer.
Or crashing, I guess.
Other than regen braking like everyone said (which really slows down a car almost effectively as brakes when set to the highest regen setting; look up “one pedal driving”), you can also slow down a car quite rapidly in a manual transmission if you skip a gear or two when downshifting. No brake lights come on when you do this, and honestly I think that they should.
I would like to share this with you: https://youtu.be/U0YW7x9U5TQ
Jake brakes in big trucks, but most of them do show brake lights now even though you just coast to activate them. Some drivers like to turn them off because it makes you look like a dangerous rookie in the mountains if your brake lights are on consistently while going downhill.
Not a car, but I’ve got a bicycle light that does this. Turns on when it’s dark and also when you brake. So definitely possible
Can you share a link to that? I’m looking for a new light.
search google smart cycle light autosense brake light.
Declaration can happen through a variety of means. Simply not accelerating would be the first one, due to friction. But even steadily accelerating on an upward slope would decrease the vehicle’s speed, and you don’t want to give vehicles behind the idea that a stop is being initiated.
You’ve spelled out the entire problem but have come to incorrect conclusions. If you’re directly behind a car, it becomes hard to sense acceleration or deceleration of other vehicles. More importantly, the brake is often used to decelerate on highways and not initiate a stop. This all leads to a lot of confusion and ultimately crashes every year.
The situations you mentioned are exactly the problem areas. Not accelerating it slowing down, often quite quickly, to make an exit. Dangerous. Going up a slope may or may not change speed, which needs to be known. Again dangerous. Same with downhill which is actually more dangerous not knowing how hard braking is happening.
So we have the technology to fix this. We can invent either variable break lights that change brightness or zoned lights that tell you “I’m slowing down” versus “I’m braking hard”. We could fix this because cars are dangerous enough as is
I always wanted a similar system to what you see in racing video games, when they display input controls. A red and green bar on the rear of the vehicle which shows accelerator pedal position, and a red bar which, in real life would have to show deceleration, as a percentage of theoretical maximum, rather than pedal position, as in the games.
Have you ever been behind a car with a driver that has one foot on the brakes and the other on the gas. It seems to resemble the effect you are looking for and incredibly distracting and annoying. When brake lights go on you expect them to be making a stop or rapid deceleration so you do the same as well as the people behind you and all of the sudden you are speeding up, slowing down, back and forth. It’s becomes a terrible way to drive. The reason we have 2 eyes is to be able to judge these things and it works fine if you aren’t driving distracted.
What if you don’t have 2 eyes?
3 eyes works just as well.
Some EVs and hybrids have a ‘one foot driving’ mode where if you take your foot off the gas, it does start to actively brake and you will eventually come to a complete stop. Technology Connections did a video on it a little while back, showing how it can be bad if the brake lights aren’t programmed to come on in this situation.
Most have KERS. This is what it is. My brake lights go on when it hits a certain % of KERS full effect.
That’s a fairly complicated system to replace what is just an ultra simple switch at the pedal. The latter is even pretty likely to last the life of the car.
They sell something like this for motorcycles because engine braking is so common. If I recall it is like a 3-4 wire install and ~$100.
The problem is with electric cars that can be driven with one pedal most of the time
I was thinking about this last time I drove an ev (ioniq 5). It will really decelerate quite hard when you lift off, and it’s configurable by the driver.
I don’t think they need to do it with an accelerometer, but if the regeneration system is applying more braking force than it would take to turn on the light with the brake pedal, it should turn the light on.
Either that or they should require the brake pedal to be used beyond that point.
Edit: actually it just occurred to me that it might be no worse than downshifting in a normal car. Maybe it’s not a big deal.
An accelerometer isn’t a good idea; but if the car’s systems are responding to a command from the driver to slow down, be that a press of the brake pedal, lifting off the accelerator in a car designed for 1-foot driving, etc. it should illuminate the stop lamps.
Most EVs do put on the brake lights when you lift off the pedal and the regen system kicks in.
The i5 does turn on the brake lights when you use regen modes. They did have a firmware update to make the logic a bit better earlier this year though.
Because there are laws that specify when the brake light has to come on, and it isn’t when the car shows down (slightly). You could be starting to go up hill, or a list of other reasons. The point of brake lights isn’t too signify the car slowing, but that the driver intends to slow down. Which is also why it doesn’t come on if you’re motor breaking" (is that the right term?).
This obviously varies wildly depending on where you are in the world. I’m also sure there are some places where it would be allowed.
Because there are laws that specify when the brake light has to come on, and it isn’t when the car shows down (slightly).
To be clear, the laws say when it must illuminate. They do not (in the US) prevent illuminating it for other reasons in any way. The law says the light must illuminate/burn if you are actively pressing the gas pedal, but does not prevent it from also illuminating if a certain amount of regenerative braking is applied or a deceleration is detected. Theoretically an automaker could get away with making the brake lights simply always illuminate (and that loophole would be fixed in days, so no one does it).
That is indeed US-specific. I’m in the EU, and here it’s defined by when and how it’s switched. Specifically, it is required to be tied to the brake pedal (i.e. then intention to brake) and/or the hand brake being pulled. It is not allowed to illuminate otherwise. But the exact specifics probably also vary by country here. That’s why I emphasized that part.
EDIT: There are actually deceleration values in some laws, possibly tied to regulation of EVs and the regenerative braking. Since that isn’t necessarily tied to the brake pedal when silmulating engine braking, but can be adjusted in strength at will (it isn’t tied to the mechanics of the drag of an idling engine as it would with an ICE). A quick google told me that the lights are allowed to come on at 0.7 m/s² and are required to come on at 1.3 m/s². This obviously implies that they are NOT allowed to come on below 0.7 m/s². This still applies only to (pure) EVs, as far as I can tell (not hybrids, and not ICE powered cars).
Yep, EU as usual having reasonable and well-thought out laws, give the US about 5 more years and they’ll make it law here too.
Which is also why it doesn’t come on if you’re motor breaking" (is that the right term?)
I believe the term you technically want is engine braking
Oh yes, that sounds right. Thanks!
There is a Technology Connections video about this xD:
Between XKCD and Alec, the whole of human knowledge’s pretty much covered.
I personally think cars should have two brake light switches. one for when you’re pressing the pedal at all, and one for when you’re slamming on the pedal.
that way the people behind you know if you’re just slowing down a little or actually braking.
Two colors, amber for slowing, red for hard braking.
I always figured red and red strobing would make sense, since amber is used for turn signals. Not sure if that would fly for epilepsy and such though, but there are plenty of other bright flashy/flickery lights when driving as it is.
Actually, a least some cars (probably more than you think)/have some sort of “emergency” breaking signal, which often result in the usual breaking signal blinking for a while. You need to seriously slam the brakes to see it though. E.g: https://m.youtube.com/watch?v=j_osu1WgGMU
There is also a nice technology connection video talking about braking lights for electric cars and in general, which can be dangerous.
I’ve seen some people play with the programming of BMWs. I was really impressed with one I saw that had 3 levels of lighting. It didn’t affect the actual brake lights but instead utilized the rear fog light. Normal braking was just the normal lights. Moderate braking turned on the rear fog lights. But when he slammed the brakes, the rear fogs flashed.
I was also pissed to be in traffic that allowed for all 3 modes in a few miles.
if you have an adequate following distance you never need to brake hard
That’s frequently not the choice of the driver. An adequate follow distance provides a luxurious ampunt of space for someone to merge into, forcing you to slow to extend the follow distance, which allows more people to merge… etc.
nope
… What?
There is no situation when one is obligated to tailgate
I rented an electric car recently (Mach-E) and almost exclusively drove in single-pedal mode.
Thought a lot about this video as I was driving.
I seem to remember that when BMW first rolled out LED taillights they did something like this — they were brighter when the driver absolutely slammed on the brakes. No idea if that was a concept or in production cars though.
I try (if I have time myself to do it without hitting someone and am just in front a mess) to “wake people up” a bit by rapidly tapping the brakes before hitting them hard (to hopefully make my brake lights flash).
You can buy special brake light kits to do this automatically.
I feel like I looked into that once upon a time and it was illegal in my state (Ohio).
I have seen something like that though, at times it’s a bit too much IMO. I’ve seen some that trigger for pretty gentle braking so there’s just a strobe light distraction in front of you over relatively minor things.
They get brighter based on how much you push the brake
deleted by creator
I know cats that blink the middle light if you brake hard.
EDIT: I’m not fixing that typo
Upvote for typo.
I reach for the hazard lights any time I’m about to break hard or if someone in front has done something that will make me slow unexpectedly.
Most modern cars now put the hazards on automatically when the driver brakes hard.
Source? I have never seen a single car that does this.
It’s a fact.
I’m a truck driver in Germany, and even my Volvo truck turns the hazards on under hard braking.
In Europe it is required for vehicles decelerating faster than 6m/s2 and I believe some vehicles might activate their fog tail lights too.
I don’t know what the system is called but it’s been around on a lot of cars for a while now. Our car does it (2016 Nissan Qashqai) - the hazards came on automatically when I had to brake hard on the motorway, and everyone else’s hazards came on too - it was exactly the reason I knew how I knew I had to instantly brake hard due to all the cars ahead hazard lights coming on with the brake lights.
I have seen several - if you press hard enough to Activate ABS on dry road, you most likely will see the hazard lights on
First time surprised me my because I didn’t know the car had the feature. Slammed the brakes harder than normal and hazards flashed at double time. Driving a 2010 Alfa Romeo 159.
A related tangent is now that there are so many distracted drivers, engine braking in a standard can become hazardous. I often will tap my foot on the brake so the people behind will register that my speed is decreasing.
Same here
I heal-toe, so I’m pressing the brake as I’m engine braking. But I think I’ve read somewhere that newer manuals actually will turn on the brake light on heavy deceleration via engine brakes, I just don’t know firsthand because every very I’ve owned has been old as shit. Ditto with electric cars that have aggressive regen braking.
I beleive that should be common practice when down shifting to slow because it’s not much different from braking without any brake lights. However, I’ve come to also trigger the lights even when coasting down in top gear. The slightly harder engine braking in a manual, even in top gear, combined with the increase of distractions, has me concerned about the same thing as you.
One foot EV driving does turn on the brake lights when it exceeds a certain deceleration amount.
But most EVs default to slowly charging the car and slowing it in a similar way to ICE compression braking (which uses 0 fuel in fuel injected cars BTW).
Anyway regardless of how the vehicle is slowing down, the NHTSA allows for the brake lights to be activated by other devices that slow the car (not just the pedal), and the UN requires brake lights be applied if the vehicle deceleration exceeds
https://unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/R13hr2e.pdf
That is not the case in the US or in the EU. Things like GM and Hyundai won’t even show the brakes with the foot completely off on full regen. You will specifically say you cannot do have a secondary braking systems as well which is where I think the issue comes in. BMW and Mercedes both only show brake lights when you fully remove your foot from the accelerator with regen turned on
I feel like thete must be a Technology Connections video about this.
Gosh that guy sure is good at talking about various types of indicator lights.
That’s 90% of good tech
That’s how the car knows to deploy the safety systems including the seatbelt and airbags
I thought the same thing about blinkers and turning the wheel.
Blinkers should be blinking before you turn the wheel. I once drove as a passenger with a driver who only started blinking after he started his manoeuvres and those 40T trucks were hammering their horns for a good reason. Scary as hell experience, would not recommend.
Kinda worthless to put the blinker on after starting to turn, no? Also, probably doesn’t work so well when you need to change lanes or turn on curves.
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