As part of the election last november in Illinois. A lockbox provision was approved so that "transportation taxes" must only be spent on "transportation." I have been doing professional engineering services and consulting for IDOT, the Illinois Tollway, O'Hare, UP, CN railways etc. for 17 years, and it STILL took me a while to go through all the legalese on that question. It seems pretty thorough; Alas, I'm not a lawyer and currently waiting for all the legal contortions that will be spent to still spend that money on things that aren't quite related to transportation.