Should I have the right to go as fast as I’d like on the highway?
“Should” and “have the right” don’t mix. You either have the right to do something, or you don’t; it’s a fact; there is nothing anyone can do to change it, so it does not make sense to ask whether you should have it. It’s like asking, “Should the Sun come up in the East, or the West?”
Under full capitalism, all roads would be privately owned. The owner of each road has the right to set a speed limit (either himself or through an agent); if you exceed the speed limit, you are not within your rights, and the owner (or an agent of his) can rightfully stop you by force.
Is it immoral for me to go as fast as I’d like?
That depends on why you “like” the speed you like. If it is a rational choice (which will, among many other factors, take into account the speed limit set by the road’s rightful owner), then it’s moral. If it’s a whim, it is not.
Now, the above assumes that the road has a rightful owner, which most roads today don’t. The government has no right to extract money from you by force, use it to build most roads in the country, and dictate the speed you must drive at on those roads. You are not violating any rightful owner’s rights by exceeding the speed limit set by the government.
However, if you endanger the lives of other drivers, you are violating their rights by doing that. And if you endanger your own life, you are acting self-destructively.
So, a rational and therefore moral choice of driving speed on a government road will take into account your own safety and the safety of others; the likelihood and severity of a punishment for exceeding the government limit; other relevant factors such as how much you are in a hurry etc.–but will not take into account the government limit other than with regard to the possible punishment.
What if instead of producing cars that were capable of speeds of 150mph, automobile manufacturers were only allowed to produce cars that were capable of speeds of 80mph? Would that be unrightful?
If by “allowed” you mean that the government would use force against them if they didn’t comply, then it absolutely would be unrightful.
This sounds rather Utilitarian (I presume it’s not)… might you care to elaborate?
The idea is that it is in your right to prevent or mitigate the consequences of a crime, but not in your right to add to them.