And they receive funding from the Federal government.
Read the rest of Title 23.
IOW, We ALL pay (and, possibly, those within the the same State pay 2x).
My own $.02 was ‘keep the inter-State system toll-free...then I remembered the N.E. I-95 corridor. Geez, anymore, you can’t drive 5 mi before you’re paying another HUGE tax (aka toll) for the, so called privilege, of ‘speedy-travel’.
Course, if we were to break it down to Constitutional norms: Unless it’s a postal road, the Fed has no authority nor responsibility = State problem, and they can do as they wish. I am still free enough to not care by using or bypassing as *I* require/wish.