Do you mean to say that one must obey the law even when, in your assessment, there is no danger [that is, if the legislator were facing your particular case, the consideration and ruling would be different]? Do you really observe every last letter of the law as if it were Torah from Sinai?
My question is about a case where I have no possibility of getting professional approval [there are no driving tests], and to the best of my assessment there is no reasonable risk in my driving—why shouldn’t I be able to decide this, just as I decide about my other forms of conduct, some of which also include a possibility of causing harm to others?
Why does the fact that the general arrangement requires professional approval mean that a person cannot evaluate his own abilities by himself? [How do they do it in places where there is no supervisory body (like in the territories)? Is it immoral there too for a person to decide on his own when to drive?]

I mean both things, exactly as I wrote. You cannot make decisions for the public. When you drive, it concerns other people as well, who are endangered by you. Somewhat like what I wrote in the column about Rabbi Chaim Kanievsky.

And if there were no traffic regulations from the government, would I then be able to make such a decision?
And if so, why, once such an arrangement exists, is my freedom of choice nullified?

Likewise, I would ask regarding all traffic laws, which as is known are determined according to what should be instructed to the public at large, but it is very possible that in a specific case, from an individual standpoint, there is no danger in violating a certain law. And since the laws are not Torah from Sinai but rather a recommendation for how it is proper and necessary to conduct oneself in general, when I have a particular reason to assume that here there is no danger, I do not see the reason to refrain from it.

From your comments here, and in the article on the coronavirus, it sounds like you are “stringent” about obeying all laws exactly as written, without leniencies or clever workarounds, roughly like the way the Haredim conduct themselves with respect to religious law. But there at least the binding source is understandable; here I do not understand it.

I already answered that, and although I did not understand what is unclear, I’ll answer again.
I am really not stringent about the laws of the state. I have already written several times in the past that one should not treat them as though they were Jewish law in the full sense of the term. (By the way, regarding Jewish law, strictness is not a Haredi matter. No connection at all.) Although “the law of the kingdom is law” applies, one should and must use common sense here.
But in the present case we are dealing with a law whose purpose is to protect other people, and therefore here you have no authority to decide on your own. You cannot decide that no danger is posed to others if they themselves think there is. It is like someone feeding you carrion without telling you, because in his opinion being careful about kashrut is nonsense, or the like. Or alternatively, a nurse at the health clinic who gives your son an injection of water instead of a vaccine because in his opinion vaccines are harmful.
Beyond that, your assessments of yourself are biased, so I would not rely on them even in themselves.
And finally, suppose we were to allow everyone to make such decisions for themselves. You surely agree that among them there would be some who make the wrong decision. If so, the categorical imperative requires not allowing anyone to make such decisions.