The smart card, which is commonly understood to be an integrated circuit-based, credit card-sized portable data carrier, is fast becoming a preferred medium for present and future Intelligent Vehicle/Highway System (IVHS) applications. Its compact size and computer functionality make it appealing for driver information, fleet management, and traffic management applications.SmartCards are currentlyused in an IVHS application, namely, in an Electronic Toll & Traffic Management (ETTM) system with Automatic Vehicle Identification (AVI). This system utilizes the smart card for secure automated payment of tolls via a two-way RF link between a toll plaza and an in-vehicle unit which contains the card. As a result of surging customer interest, additional ETTM vendors are considering the use of the smart cards for their systems.Other applications of a smart card-based AVI system include vehicle speed calculation for measuring trafficflow,fleetmanagement (i.e., rental car entry/exit), and various traveler information services. A smart card may also be used for logging of vehicle maintenance records, thusproviding a higher level of customer service for vehicle owners. Another application is advanced vehicle diagnostics, where critical data could be stored on the card at the touch of a fingertip in order to more easily diagnose intermittentvehicle problems. Further, a smart card could be used for data storage in tracking and measuring driver and vehicle behavior for fleet managementapplications. Undoubtedly, new IVHS applications of smart cards will continue to evolve into the 21st century.