I'm not aware of a "freedom to speed" under either the US Constitution or the EU's Charter of Fundamental Rights.
Speeding falls under the "expedient" category of crimes: it's been illegal this entire time, but selectively enforced for practical reasons. Nobody wants to live in a society where a sufficient number of police are chartered to universally enforce speeding laws, so this seems like a very reasonable solution.
Please see the 10th amendment. "Freedom to speed" is reserved for the states to decide. However, like the Federal Government has done in the past (the since repealed National Maximum Speed Law), it may attempt to persuade states by withholding some, but not too much funding (South Dakota v. Dole).
No, the 10th Amendment doesn't guarantee you the right to speed. The closest thing would really be the 9th Amendment, but even that doesn't imply a positive right to speed -- the strongest argument would be that nothing forbids a right to speed, which in turn must be justified as an actual right. Which, in fact, it is not.
(What you're describing has nothing to do with speeding under the law, which doesn't care whether different states have different maximum speeds. Speeding isn't a Federal crime, and when we're talking about it the sole thing we're talking about is the individual State laws that describe speeding in the US.)
It's a sad state of affairs. Liberties are being killed one after another usually in the name of safety as-if all EU citizens are living in extreme fear and danger.
From deanonymization in crypto to Corona pass and tight border control and lockdowns people are being treated as the lowest common denominator - terrorists, money launderers and criminals.
I feel the opposite about America. We have many consumer and social protections that Americans don't. They seem to value freedom over the well-being of the average citizen.
Perhaps we'll never have as many nobel prizes per capita, or as many millionaires, but I quite enjoy things being regulated in favour of the average citizen.
Speeding falls under the "expedient" category of crimes: it's been illegal this entire time, but selectively enforced for practical reasons. Nobody wants to live in a society where a sufficient number of police are chartered to universally enforce speeding laws, so this seems like a very reasonable solution.