Why did you ignorantly say the Constitution lacks a provision without reading the Constitution before commenting?

Yes there is something in the Constitution that says the federal government must build and maintain an interstate highway system. It's in the Postal Clause. Article I, Section 8, Clause 7, empowers Congress "To establish Post Offices and post Roads".

Too bad you're too lazy to make the effort, especially citing "only 17 pages long."

You also imply that if Congress passes an unconstitutional law, it's okay to pass more of them. That defeats the purpose of the Constitution and a federal government with powers that are "few and defined."

As for your other ignorant and incoherent statement, if Congress can "only" do what the Constitution specifically says then limited government, state sovereignty and a Constitution that serves its correct purpose. If we don't have a Congess to pass laws, who else would they be passed?

Try reviewing your comments before posting.