Asking this question explains a lot of why things are a bad as they are.

The act itself is unsafe and could kill you or another person so the punishment is supposed to act as both a deterrent from doing those things and a response to irresponsibility that put others in danger.

There are acts that we've determined are unsafe enough that we don't want to allow them so even in a "successful" execution of that act you still violate a law.

Because you weren't able to know nothing bad would happen. Your guilt is dependent on the risk you took.

Imagine shooting a gun with your eyes closed in a random spot. Is it ok to do if noone was in the line of fire?

It's shocking how, despite all the response, no one has presented a clear general case.

It's called risk management. We learn about risk when a bad thing happens. When a bad thing happens, that means it was possible for it to happen. The next question is "under what conditions will this bad thing happen again". And as it turns out, there is no deterministic answer to this question. It's all probability.

So condition X increases the probability of bad thing Y happening by amount Z. When a bad thing (Y) happens, we commission studies to look into all the possible conditions (X1, X2, etc) that contribute to Y and what the probability increase is for each X.

Armed with this information, we then set about the political process of determining the negative value of the bad thing and the negative value of eliminating the contributing conditions.

So for example, people get skin cancer (bad thing). The sun is a contributing condition to people getting skin cancer. If there was no sun, less people would get skin cancer. But if we destroy the sun, we destroy all of humanity. So addressing the condition of "the sun exists" is more negative than the bad thing "some people get skin cancer".

Following the same example, another condition for skin cancer is that the skin lacks the physical ability to protect against the sun's harmful rays. We could solve this by forcibly genetically engineering the entire human population, or by forcing everyone to wear a poncho or burka, or by forcing everyone to wear sunscreen. But politically, we have chosen that since skin cancer's largest impact is in the individual who develops it, and that the social cost of skin cancer is small by comparison, that the negative effects of removing bodily autonomy from everyone are worse than the bad thing "some people get skin cancer some times".

So now we arrive at the final component of why we punish people for contributing to the conditions that increase the probability of bad thing happening. Social impact.

If the bad thing we are analyzing affects a lot of people AND the bad thing happens to people who are not exclusively the people who brought about the conditions that increase the probability of the bad thing, then we, as a society, sometimes decide that the best way to reduce the bad thing occuring is to reduce the probability that it will occur and that it is socially acceptable to punish people who raise the probability because that punishment will reduce the frequency and volume of that behavior and therefore reduce the frequency and volume of the bad thing.

In the example of speeding, it's easy. Speeding is totally legal for drag racers on a closed track and no one punishes them for going too fast. They might kill themselves, but that's on them. But speeding on public roads leads to the death of people other than the driver. The driver could also die, but especially with pedestrians and cyclists, the speeder usually survives but other people die because of the speeder's behavior. These things also happen when people drive the legal speed limit. In fact, it's just a reality of living in a society with tons of motor vehicles.

But the research shows speed is a major contributor to deaths of people other than the driver, and that limiting speeds absolutely results in fewer deaths caused by motor vehicles. In fact, literally every single speed limit set in the world is backed by a speed study that you can challenge with empirical evidence and trigger an empirical review to determine whether the speed limit is set too high or too low.

We could go to the next step and automate speed governance. We could require all cars be installed with a speed governor, we could put up digital beacons to announce speed limits and require all cars be designed to respect the speed limit at all times. But, we have decided that the negatives of doing that are worse than the number of deaths caused by motor vehicle accidents where speed was a contributing factor. Costs would be very high, effectiveness would be very low at the outset, false negatives and false positives would be rampant, and people could disable their governor system and then we'd still need traffic monitoring to catch the speeders (although disabling the governor might be punished by jail time and vehicle destruction).

It's all math. We do it because the math shows that it works. Reducing the risk factors of a specific negative outcome reduces the negative outcome. And we do it because we do not want to wait for every single human being to have to experience the bad thing to learn to govern their own behavior, especially when that bad thing could be the death of innocent people.

Same with killing if you are caught by the cops, you should be free to go home.

Tesla ... The car is driving itself quite well

hahahaha

Nothing bad happened yet. Keep doing it, and something bad's going to happen. An ounce of prevention is better than a truckload of cure. Some things can't be cured. You can't punish someone hard enough to undo road deaths. The victims are still going to be dead. They don't come back to life once the killer goes to jail. There is no other reasonable way to handle road deaths than by stopping them before they happen. Drive at a reasonable and appropriate speed, or someone's going to die. Those are your options.

No it's not a perfect solution, people still die on the roads, and they probably always will, but we've chosen the speed limits at a point that prevents some deaths, you cannot realistically argue that, and that is all you have to know to understand that they are justified, and they do have an appropriate punishment.

Does that help you understand?

Why should we punish someone doing Russian roulette while holding a gun against another persons head if nothing happened?

There is a risk threshold that gets crossed due to certain actions. They're punishing rolling the dice, not the result.

Because rational thinking isn't common and some people have to be told or discouraged to not do something dangerous or reckless. Your example is oddly specific, sounds like you got a ticket for putting your Tesla in self driving mode and starting making tik toks and got a ticket.

Imagine someone points a gun into a crowd, closes their eyes, and pulls the trigger, but the gun jams so no bullet is fired and everyone is fine. Do you think that person should be let off scot-free just because nothing bad happened?

By this logic there's no problem with Russian roulette... well, until there is. Same general concept.

Because the whole idea is to discourage people from behavior that is likely to cause bad things to happen. Obviously when bad things happen we go "I wish someone had stopped the person before people died".

If everyone started driving 10 kph over the speed limit we'd see a significant uptick in the rate of accidents. That is just a fact.

We don't want that so we've set limits that still get you where you're going as fast as possible while keeping that particular stretch of road relatively safe. To enforce those limits we've decided that if you get caught going over you get punished for it. Not for driving fast per se but for breaking the rules you agreed to in order to be allowed to drive there in the first place. Fining you even when you didn't get into an accident is just carrying out the threat so that it keeps its credibility.

To actually answer the question: because bad things happened.

First of all, this is a public road used by a lot of people. This is a shared space/resource that we all want to benefit from, and that means that it needs to be safe for everyone to use it (otherwise, people are not going to use it and thus no benefit from it).

By speeding (or letting a Tesla do the self-driving without paying attention), they broke important rules. The other point is that had there been an accident, then we would have punished the person for the accident too.

We can argue about whether a given speed limit is adequate for a given stretch of road, but the core of it is that someone (usually experts) settled on a speed under which it is safe to travel. Going above that speed means that you are now taking on more risks than accounted for when designed.

Why is breaking these rules bad? Because, for example, normalization of deviance. The long-story short is that safety rules are an important part of keeping a system safe, and ignoring them removes the safety margins built into the system and either makes accidents more likely, or makes any accident that does happen more disastrous.

To stay around the speeding example, consider the following: people take a set amount of time to react. The faster you go, the more distance you need to react. If you are traveling down a road, and an animal crosses 100 meters ahead, the faster you go the less time you have to react.

Also consider the following: roads are not perfect. If you go over a patch with sand, or a recently-rained-on surface, you may end up with much less grip than you thought you did, and you end up spinning on the turn, or not breaking enough. And you won't know you need it until you do, and now you're too late to not speed.

If you were on a private road? Good luck. Its on you. But you are in a public space, and it's likely you're putting others at risk, either directly, or by (as linked above) normalizing deviance and making it more likely for others to not follow the rules when it matters.

punish people when nothing bad happened ?

Well, we don't. We just make them pay a fine.

But where are you from, where is it a punishment?

1. Cars are generally made to take impacts at certain, reasonable speeds. Going too fast and the safety features may fail. Add in your response time goes DOWN significantly as well. So you're going 40 in a thirty and a kid runs out in front of your car. That's more energy needed to stop from turning the kid into a road statistic. When you're speeding, you're gambling or taking a mathematical risk. And I'm here to tell you, luck runs out or a lot of people are really bad at math.
2. This goes with the end of number 1. You're taking a risk, you're significantly increasing the chance something WILL happen. The Tesla cars are not "self driving" as it's been showed to be a load of bunk. They can assist heavily but they will make wrong maneuvers given enough time to do so. There's been at least a dozen articles I've seen of a Tesla driver getting into a collision because they were asleep. Most of them end up badly for SOMEONE in the collision.

I'll assume you are asking in good faith / out of innocence, because this isn't a question that typically needs to be asked if you've lived with any group of people for some time.

Let's put laws aside for now, cause they can make this explanation more complicated than it needs to be.

Suppose you like jumping off cliffs for fun, and you've been skillful enough to not fall to your death. You jump off, feel the thrill, and you land safely — nothing bad happens. All is good.

One windy day, branches were flying around, and it was dark out. You wanted to jump anyway because, well, why not?

You jump.

A branch hit your face and scraped near your eye. You winced. And because you couldn't see well enough, you couldn't land like you always would. You didn't die, but you certainly got hurt, bad.

So you thought to yourself after that incident: maybe I shouldn't jump when it's windy and dark out, or maybe I'll wear eye protection when I jump.

You'll tell others not to do the same. Not everyone listens to you, because they thought, well, maybe you just weren't "careful enough". Maybe you don't care enough if they would believe or listen to you. But some people that you do care, say, your kids, also don't seem to listen to you. Despite your warnings, they'd still sneak out at night, on windy days, to go jump off the cliff for fun.

So what would you do?

Risk is high even if nothing happens. It's all about probability.