[windows2020]

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 However, like the Federal Government has done in the past (the since repealed National Maximum Speed Law), it may attempt to persuade states by withholding some, but not too much funding (South Dakota v. Dole).

[woodruffw]

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.)