E-ZPass is a toll collection system in the northeastern U.S. that uses RFID technology to allow a driver to pass through a tollbooth and pay the toll without stopping the vehicle. Typically, the driver pre-pays a month of access tolls and is issued a transponder (a tag about the size of a deck of cards) that gets mounted on the inside of the windshield. When approaching a toll, the E-ZPass driver passes through a special booth that has an antenna. The antenna emits a radio frequency (RF) field that activates the driver's transponder, which in turn, sends back information about the driver's account to the antenna. The toll is then deducted from the driver's pre-paid account. E-Z Pass significantly cuts down on labor costs for toll collection and keeps the lines of traffic moving faster.
Mobil Corporation uses a similar technology to enable drivers to purchase gasoline by using a transponder that attaches to the driver's key ring. Both E-ZPass and Mobil are experimenting with licensing their transponder payment systems to non-competitive vendors, such as McDonald's, who wish to move traffic through their fast food take-out windows more efficiently.
In California, a system similar to E-ZPass is called FasTrak.