Last night, I couldn't sleep, and in my wakeful state, I allowed the river of thoughts to take me wherever it wanted to flow. This led me to a question: "Who is accountable if a truly driverless car hits and kills a person?"

I conducted a bit of a Google search, but unfortunately, the first 20 answers all discussed accidents involving non-truly driverless cars, where a person is in the driver's seat. My question specifically pertains to cars without drivers, such as Cruise in San Francisco.

To make this question more philosophical, I want to emphasize that the cause of the car accident is indeterminable by experts. Having a bit of knowledge in software engineering myself, let's assume that it's entirely possible for some software behaviors to be unreproducible, with or without a black box. For instance, high-energy particles from the Sun could induce bit flips in memory or CPU, leading to abnormal computer behavior. Thus, we cannot simply approach John and say, "Hey John, your PID controller should have an additional if statement here to prevent high-energy particles from the Sun messing up the CPU."

To add an interesting twist, in this accident, if we replace this driverless car with a normal car with a driver, then the driver is undoubtedly going to jail due to their misbehavior. (Edit: I don't know why I am adding this comment here. I think this paragraph clearly defines the situation. But it seems that there is confusion here, so I am adding more information here. The situation is not about if the driver is intentionally making the car accident. Just purely judging by the result, the driver is going to jail. E.g., the driver goes through the red light and kills a pedestrian. Now, there are many possibilities as to why a driver would break the red light, but let's just say it's the driver's fault, and he/she is going to jail because of his/her behavior. Also, there is still no driver in the driver seat. This paragraph is just making the point of the car accident. If I don't add this paragraph, there will be answers about it may not be the fault of driverless car in the incident, which is not the point in which I am interest in this question.)

Now, after defining the conditions, I want to ask the question: "Who should be responsible for this car incident?" My humble thoughts are listed below:

  • No one. Companies (or the government) should be fined and pay compensation to the victim's family. Let's consider it the shared price we all have to pay when striving to transcend ourselves in the history of mankind.

  • Shared responsibility among the employees of the company. If the total sentence is 3 years, and there are only three people in the company manufacturing this car, then each person goes to jail for one year.

I cannot find other options, and I genuinely dislike the first option while finding the second one somewhat silly. However, if I were the judge, I would lean towards the second option. Please share what the current law and regulation are regarding this case.

Note: I don't live in San Francisco or in the U.S., so I am not following the latest regulations regarding this matter.

Edit: I changed the title from "Who is going to jail" to "Who is accountable".

  • 1
    law.stackexchange.com/search?q=self+driving Commented Dec 14, 2023 at 3:28
  • Unfortunately none of the answers above answer my question. Please read my question carefully. Thank you.
    – Lion Lai
    Commented Dec 14, 2023 at 4:24
  • 1
    In a car with a driver, a fatal crash does not necessarily mean anyone goes to jail. Only if it’s something like vehicular manslaughter, which takes into account the driver’s actions, such as being drunk or extreme reckless speed.
    – Damila
    Commented Dec 14, 2023 at 5:56
  • 1
    have you read en.wikipedia.org/wiki/Self-driving_car_liability ? Currently it's a very grey area of law, as in, unregulated in many practical aspects. In part, because it's currently not legal to leave the driver's seat and not be in control of the car in most states and countries. There is legislation in place on some things, but no car has been found to be the required level 4 or 5 to allow the computer to take over fully.
    – Trish
    Commented Dec 14, 2023 at 8:08
  • "Hey John, your PID controller should have an additional if statement here to prevent high-energy particles from the Sun messing up the CPU." Except that is what exactly happens when coding safety critical systems (albeit not explicitly called out for high energy particles from the sun). There are multiple levels of redundancy and checking of the data and systems.
    – Peter M
    Commented Dec 14, 2023 at 13:46

5 Answers 5


the cause of the car accident is indeterminable by experts

As for the law, it's the jury that makes the determination, not the experts. The lawyers for each side orchestrate the arguments to the effect that their side is not responsible and that the other side(s) are responsible. Nobody is going to jail (not even with a human driver), but somebody might have to pay.

Legal responsibility is not an all-or-nothing proposition. The manufacturer might be 45% liable for negligent manufacturing, the car-owner might be 35% liable for negligence in controlling their car, the victim might be 10% liable for some thing that they were doing that resulted in the accident, and the guy driving the other direction might be 10% liable for some swerve that triggered a bad reaction by the auto-auto. That tells you that the victim's family might recover 90% of the damages, spread out across three plaintiffs.

The essence of the argument for liability is that the party negligently did not exhibit the level of care that a normal person would. For example, if they know that a simple line of code could prevent the accident but they couldn't be bothered, and if the opposing side can prove this, then they might be found liable.

  • The person sittin in the driver's seat could be, by default, 100% liable because he is, under the law as written, the driver and if he is not in control he's iable.
    – Trish
    Commented Dec 14, 2023 at 7:58
  • 1
    @Trish But with true autonomous vehicles there is likely to be no one sitting in the drivers seat.
    – Peter M
    Commented Dec 14, 2023 at 13:48
  • You seem to be talking about the lawsuit end of the situation. The question is about the potential criminal proceeding. They're two different legal actions. Commented Dec 14, 2023 at 21:52
  • @DarthPseudonym The headline question is criminal liability, but the body text also asks ""Who should be responsible for this car incident?"
    – ohwilleke
    Commented Dec 15, 2023 at 20:00
  • @ohwilleke Yes, and then immediately starts talking about jail time. This question is talking about criminal prosecution. Commented Dec 15, 2023 at 23:52

Why does anyone go to jail?

There are such things as pure accidents where no one is responsible. For example, a driver who collides with a pedestrian during a sneezing fit is not responsible for the accident.

For there to be responsibility, there must be, at least, negligence. For criminal responsibility, that must rise to the level of, at least, recklessness.

  • Most jurisdictions have a crime of criminally negligent homicide or vehicular homicide for which criminal negligence is the mens rea rather than recklessness. But criminal negligence corresponds to gross negligence and not just ordinary negligence in a civil action for personal injuries.
    – ohwilleke
    Commented Dec 14, 2023 at 19:28
  • I downvote your answer because your answer is about the existence of a driver which i clearly asked in my question that it's a truly driverless car.
    – Lion Lai
    Commented Dec 18, 2023 at 3:01

To add an interesting twist, in this accident, if we replace this driverless car with a normal car with a driver, then the driver is undoubtedly going to jail due to their misbehavior.

This is not true. It is unusual for there to be a criminal charge that arises from even a deadly car accident. It happens, but it is the exception rather than the rule and is reserved for cases of exceptional driver culpability.

Who is going to jail if a truly driverless car hits and kills a person?

This is a separate issue from civil liability for money damages.

Usually, the driver has to have criminally negligent or reckless or have greater levels of intent to commit a criminal offense.

It would be rare, in the case of a self-driving car, for the driver or owner of the vehicle to have the necessary intent to be guilty of a criminal offense in an accident where the driver was relying on the self-driving vehicle to avoid accidents.


At the time of writing, 14 December 2023, the person behind the wheel or otherwise in charge of the vehicle is responsible for the vehicle.

In early November 2023, the Government introduced the Automated Vehicles Bill, which, among other things, will purportedly have this effect if Parliament makes it law:

Every authorised self-driving vehicle will have a corresponding Authorised Self-Driving Entity – often the manufacturer – which will be responsible for the behaviour of the vehicle when self-driving.


The person who put the car on the road thus creating the hazard would be responsible. Note that most things that would send someone to jail due to an accident are due to intoxication or reckless operation, and I suppose it would be up to a jury to decide if putting a car on the road without a driver were reckless or not.

  • The most likely civil lawsuit defendant would be Tesla on a product liability theory. "Putting the car on the road" is not a well defined act giving rise to civil or criminal liability.
    – ohwilleke
    Commented Dec 15, 2023 at 19:58
  • @ohwilleke, the question was criminal
    – Tiger Guy
    Commented Dec 15, 2023 at 23:55

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