An electronic device that processes tolls from a prepaid account. A set of readers at AET gantries and other toll collection communicates with the transponder to automatically deduct fees from motorist's accounts. Transponders are usually referred to as a toll pass or toll tag. There are a number of toll systems in use across the country with some interoperability between agencies. The long term goal is to have all systems interoperable, so that a driver using an E-ZPass from Pennsylvania can drive on a GeauxPass based toll road in Louisiana and vice versa.