The beauty of ETC is that the agencies generally don't care where whether you live in the state(s) in which you're driving - as long as your money is green, they'll sell you a tag. You can pick up a tag in NJ and use it anywhere in the EZPass area (or affiliated, but not entirely integrated, states, like IL). I know that there's some forward motion to a national ETC standard, which could eventually lead to interoperability between EZPass and isolated systems, like FL SunPass, TXTag and CA FasTrak, but that's still quite a way off.