jyoung8607
4 hours ago
I'm not an expert in the LLM space, but I'm an external contributor to comma.ai's openpilot project and I'm and quite familiar with how its controls work, so I looked from that perspective. There's two questions here:
1) Could a cloud-delivered LLM figure out how to drive this route, based on those input data and given access to those output actuators? Looks like yes. Sure.
2) Could this work in the real world? Absolutely not. Three reasons: latency, latency, and latency.
openpilot's driving model updates the target curvature and acceleration at 20Hz. Every millisecond of the round trip time through every piece of its entirely-local driving stack is well-understood, extremely consistent, and tightly optimized. It has to be, otherwise you can't react to even minor bumps or wind gusts, much less rapidly-developing traffic situations.
Adding even a single speed of light RTT to a cloud service is meaningfully bad, and you'll need a whole lot more to encode and upload camera imagery to even start the time-to-LLM-response clock, and then send the response back down. By then the world around the car has moved on.
There's a reason Tesla and every other self-driving manufacturer need the compute hardware in the car.
aditya-ramabadr
4 hours ago
Great point! Yeah latency was one of the biggest issues here. To cope with that (and for safety reasons) the cars are driving at extremely low speeds. They also get timestamps with every tool call output etc so they can, in theory, "in context learn" about their own latency and choose motion durations and control how fast their iteration loop is to some extent. But yeah, this is just sort of a fun benchmark to see how good frontier LLMs are out-of-the-box at driving a real car, and probably not actually practical any time soon.
-Aditya, Tobias, Simon
jyoung8607
4 hours ago
To clarify my parent comment, I think it was an interesting experiment and seems like it was done well, and it may well be informative about what various frontier LLMs could do with recorded or world model footage.
My only point is to say this sort of experiment is where it ends. Neither Anthropic nor OpenAI will be coming out with a "drive your car from the cloud" subscription until we have FTL communication, meaning never.
sashank_1509
3 hours ago
Is it plausible they can use the large GPT model, to distill a smaller car driving model only from it and then run that onboard. Seems like that will solve all your issues.
Xmd5a
3 hours ago
What about Waymo's remote controlled cars? Why is this not an issue?
jyoung8607
12 minutes ago
The car always has to be capable of driving safely and avoiding collisions locally. The human operators are being asked occasionally to help with some higher level, longer term decisions. As a random example, if there's foreign objects blocking the road, the car has to be able to stop itself before hitting them, but it might phone-home to a human to decide if a u-turn is appropriate.
rented_mule
2 hours ago
My understanding is that Waymo's remote driving is not direct control of the car, for exactly these reasons among others. So human operators don't have steering wheels or joysticks. Instead the humans can give something closer to advice (e.g., "pull to the right and stop") that the car can accept, modify, or reject.
bayarearefugee
an hour ago
> Could this work in the real world? Absolutely not. Three reasons: latency, latency, and latency.
That and also the fact that (in spite of their usefulness) LLMs still so often do incredibly dumb shit without thinking of the consequences that the idea of having them drive in public is absurd.
Recently was using claude code/opus 5 to diagnose an intermittent wi-fi connection problem and one of the first things it did was to bring the adapter down. The wi-fi adapter was the only way the system was communicating with the outside world so claude effectively disconnected its own brain as step 1 in figuring out what was going wrong. Things did not progress well from there. Easy enough to clean up its mess in this case, but luckily it wasn't driving a heavy killing machine at the time.
ivanjermakov
4 hours ago
> otherwise you can't react
I'm far from neuroscience, but humans don't need to operate at 20Hz to drive a car. And human reaction latency (event to measurable action) is often over 1s (under 1Hz).
chaos_emergent
4 hours ago
The reaction latency you’re referring to for humans includes perception, planning, and actuation, I’d separate that from the concerns of the hardware, which are mostly about actuation frequency.
From what I understand about AV (as a non-expert!), all three of those steps happen at different clock rates, ie you have a planner that’s updating continuously with observations from sensors at one rate, that planner then issues actions that get picked up by the actuators at another rate.
In that sense 20hz should really be compared to human reflexes without perception and planning; in scenarios where one is anticipating an action, response time can be as low as 150ms. in that context, I think 50ms/20hz is plenty reasonable for an automated driver.
gpm
3 hours ago
In circumstances where one is maintaining grip or muscle tension (e.g. steering a car) I believe human response time can be more like 50ms. Which perhaps unsurprisingly lines up with the 20hz figure pretty close to exactly (we built cars controls so that they're controllable by human reflexes).
Though you can't convert between hz and latency, all 20hz tells us is that it adjusts 20 times a second, not how long it takes from sensor input to be fed into a particular choice of adjustment, there could be (and actually almost certainly are) multiple adjustments in flight simultaneously with the adjustment actually being applied being calculated from old data (both in humans and automated substitutes).
ASalazarMX
21 minutes ago
Average human reaction time is about 250 ms, or 4Hz. That's still plenty fast for an attentive driver at reasonable speeds. More important, it's consistent when not distracted. Any LLM with latency would be like a driver constantly checking their phone.
jacquesm
2 hours ago
Humans have multiple layers of processing such inputs and your subconscious reacts a lot faster than your conscious train of thought in case something happens (and then you have to 'catch up'). For the same reason that you don't consciously think about what you do when you are walking or how to stop yourself from falling when you stumble. That's all out of the top level and pushed further down to stack, sometimes even multiple levels.
mirrir
4 hours ago
I'm not an ornithologist but birds don't need to consume jet fuel to fly hundreds of miles either.
bonsai_spool
4 hours ago
> but humans don't need to operate at 20Hz to drive a ca
This is not a helpful statement unless you can claim what speed human sensors do work at. And it's going to be faster than the latency of $(sensor + server round trip) Hertz, not getting into LLM processing time.
nearbuy
14 minutes ago
Are you asking for the latency or throughput?
In humans, it's about 200–250 ms for a visual cue where you already know how to respond and you're ready, but you don't know exactly when it'll happen. It can be a fair bit longer if you need to identify what you see and choose how to respond. Typical perception to reaction time estimates for drivers when there's an unexpected hazard on the road are 1-2 seconds.
Groxx
4 hours ago
It's also not subject to signal loss issues like anyone who uses a phone is quite familiar with. Unless you have narcolepsy.
cozzyd
4 hours ago
Let's see how well you play counterstrike with a 100 ms ping...
replygirl
4 hours ago
reaction latency doesn't cover everything. the round trip from trigger to action is a few hundred ms at best, yes, but to enable that we are processing inputs at ~30hz minimum and integrating at ~5hz. you would total your car pretty quickly if you couldn't constantly adjust
suddenlybananas
3 hours ago
>human reaction latency (event to measurable action) is often over 1s
This is so self evidently false, I struggle to believe you think it is true. How could anyone catch a ball even?
asah
35 minutes ago
actually, human latency is quite slow and distracted drivers often have 1sec+ latency.
it works because 99% of the time you don't need fast latency because you can accurately predict things.
that's why a standard recommendation is to drive 2+ seconds (time not distance) behind the car in front of you. also why experienced drivers instinctively move their hands/feet into position during tricky moments when they need to cut the latency.
fun exercise, try taking your foot off the gas and hitting the break - slower than you think!!
blactuary
3 hours ago
Kind of funny to mention comma today of all days
ex1fm3ta
24 minutes ago
It is also worth mentioning that the openpilot AI model is a world model. The way a world model understands physical reality and geometry makes it inherently safer for driving than an LLM, which is essentially a text-based statistical machine with no concept of the physical world.
odo1242
3 hours ago
You can see this in the photos, it took over five minutes for the cars to get around the cone course.
pishpash
2 hours ago
Yet remote pilots can fight wars on the other side of the world?
Insanity
2 hours ago
Flying a drone with e.g 1000ms RTT latency is not exactly the same as driving a car on a highway. There are typically less collisions in airspace.. :)
jacquesm
2 hours ago
There are fewer obstacles. That's the main reason it works, if you tried flying at 1 m above the ground it would become a lot more like driving, but without the benefit of friction. Flying requires less strict constraints on latency because it happens in straight line segments that are rather longer than the segments that you use when controlling a vehicle.
aaroninsf
2 hours ago
Is that the same comma.ai project also in the news today?
https://arstechnica.com/cars/2026/09/aftermarket-driver-assi...
Onavo
4 hours ago
> Could a cloud-delivered LLM figure out how to drive this route, based on those input data and given access to those output actuators? Looks like yes. Sure.
Well, if the massive cloud models that are generalized and have a world model that's good enough, you can just distill them into smaller models. As a point of reference, the current gen of Tesla FSD models only have 1B params. They are tiny by LLM/VLM standards.
chaos_emergent
4 hours ago
Wow, I had no idea that they are so small, that’s incredible! Really goes to show how much visual information can be compressed.
Onavo
4 hours ago
The next gen (v15) is supposedly going to be around 10B.
ramesh31
4 hours ago
Perhaps there's a synthesis to be had though. Eyes, control, and safety critical features on the hardware, higher level decision making to the cloud. Openpilot's biggest weakness has always been in the very "robotic" way that it drives, which is technically correct but causes frustration for other drivers. Deciding "should I pass this car" is a fundamentally different question to "can I pass this car", or "what is the actual safe speed and following distance given the current traffic conditions and weather".
simianwords
4 hours ago
How are you so sure that latency can't be improved? Sol can run on cerebras and we may get enough efficiencies that Astra can also be run locally.
nijave
2 hours ago
Even if latency is improved, it's still a monumental task powering a latency sensitive safety critical system over the internet--especially one that's moving.
Maybe if latency can be improved _and_ it can run local inside the vehicle.