I just got pulled over by the Utah Highway Patrol on I-15 by Lagoon. He told me it was illegal to drive in the car pool lane by myself. I pointed to the very small "C Decal" that is properly affixed just to the right of my rear view mirror. Having the decal allows free use of Express/HOV lanes for single occupant vehicles and is available for qualifying clean fuel vehicles. Referring to the decal he said, "This is the first time I've ever seen one of those before." and then apologized for wasting my time. The C license plate used to be used for the same purpose. It obviously made it easy for the UHP to tell if a single occupant vehicle was authorized. The decal sticker is almost impossible to see. On the other hand maybe they should just assume that if the car is a Tesla (or any other "green" vehicle) that they've got the sticker? Here in N. Utah I've only seen three other MSs besides my own, so most UHP officers are probably unfamiliar with the car. Afterwards I thought maybe I should have said "This car is a 100% electric Tesla Model S. It is pretty recognizable, and it's probably a safe assumption that it has will have the C Decal".