Constitutional FAQ Answer #62
Q62. "I have a friend that told me that I have a constitutional right to travel in this country. He stated that to tax that right with driver's license fees, motor registration, license plate fees and a gas tax is unconstitutional and that some people resist this 'violation' in various degrees by challenging then in a court of law and eventually having them overturned. Is there any truth to this and what do you base your arguments on."
A. You don't have an explicitly stated constitutional right to travel within the country, but since you are not restricted from interstate travel, the 10th amendment says you have the right anyway. It could be reasonably argued that Article 4, Section 2, Clause 1, presumes the right to travel between states when it says that a citizen of one state shall have all the rights of a citizen of another state.
Driver's license fees, state gas tax, license plate fees, registration fees, and any other auto tax imposed by the state are entirely constitutional under the U.S. Constitution, which basically says the State can do anything it wants to, as long as the Constitution does not expressly forbid it. Unless that state's state constitution forbids such a tax, it is legal.
Federal gas taxes are constitutional under Article 1, Section 8, which states that the Congress can lay excises, which is what the gas tax is.
So it's no wonder that any case challenging these taxes is thrown out of court.