I am a Bay Area resident. I thought that if I am in my Tesla and go through a bridge toll booth in the HOV lane that I pay less but still have to pay something. See
FasTrak - Keeping the Bay Area Moving
Quote:"California law allows single-occupant use of High Occupancy Vehicle (HOVs) lanes by certain qualifying clean alternative fuel vehicles. Eligible clean air vehicles may use the FasTrak carpool lanes on bridges and qualify for the discounted toll rate with an active FasTrak tag."
I use the external license plate mounted transponder.
You left a line out of your quote. It went on to say "
Eligible clean air vehicles do not require a FasTrak tag to use the Express Lane network."
What all that means is that if you have a MS, you don't need the transponder for express lanes. It also means, but doesn't say explicitly, that if you do have the transponder, you get charged. FasTrak transponders aren't tied to specific vehicles, but vehicles are tied to specific accounts. So if you have three transponders and three vehicles, you can put any transponder in any vehicle. In an HOV lane, you need to remove the transponder to avoid the charge. They don't have anything in place to tell how many occupants you have, or whether you are in an electric vehicle. If you have only one vehicle and one transponder on the account, it's almost a given that you were in an EV. But even at that, you have the right to carry your transponder with you when you use Uncle Joe's Plymouth Duster. So the bottom line is that turning it off is the only way you can avoid paying tolls in areas where you don't need to pay, and having a transponder is necessary for carpool lanes on bridges where everybody in the lane pays the same discounted price.
That being said, I have more vehicles than transponders, and never got a letter related to using the license plate method. But I suppose it comes down to them not knowing what transponder I would have used had one been there. If my wife uses hers daily, it won't get associated with a plate since the transponder gets read and there's no need to look at the plate. So when a plate gets read and there's no transponder, they don't know if it's a case where the one my wife uses simply didn't register, or whether it's a different vehicle with no transponder. That probably explains why I'm way under the threshold for plate scans vs transponder readings.
I've heard of people in SoCal being pulled over for not having transponders, even in cases where they wouldn't need to pay. I think you'd be able to win that one in court, on the grounds that state law requires all FasTrak systems to be compatible with each other. Since BA FasTrak transponders need to be removed in mixed use lanes, it follows that the SoCal system should be required to work with no transponder when there's no toll. The SoCal transponders have switches that can be set to the number of occupants, so if a Tesla had one in the bumper with the switch permanently set to 3, it would work. But you can't have a transponder from one part of the state when its use is almost exclusively in another part of the state.
The best situation would be for Northern California to introduce transponders with switches. If everybody reading this thread contacts a legislator, it won't be quite enough, though.