Yes. Keep your switchable FasTrak transponder(s) to be eligible for carpool discounts on designated express lanes throughout California. You can have, both, your sticker transponder and switchable transponder mounted to your windshield at the same time. The switchable transponder becomes the default transponder and the appropriate toll will be collected based on the settings on the switchable transponder. For information on carpooling with FasTrak, visit: TheTollRoads.com/Accounts/FasTrak/California.