Second, the market already has developed digital cash, similar to a prepaid long-distance card. Just as you can now purchase long-distance telephone minutes anonymously at convenience stores, you would be able to purchase toll-road miles with cash, and stick the magnetic miles card under a fender. Road owners and transaction-management networks would never have to know who you are. This technology is already in widespread use. Only if you prefer to drive on credit, and be billed monthly by a network management provider, would there be any possibility of an electronic record of your whereabouts. And there would be a market even for this—for example, many young, single women, such as college students and young professionals, might desire that someone, somehow can always find out where they are.