[rjsimmon]

Yes, so how do the police on the ground know if a single driver has flipped on his/her switch or not?

The Flex Pass is an RFID transponder. When queried it responds with its current mode. Either HOV or single. The police have RFID query devices and can validate much like a RADAR gun.

[tgusa]

Thanks. That explains why there are always several State Troopers waiting along the HOT lanes. Now we know.