[Jess Kitting]

The trick is to know how they determine people are attempting fraud when flipping that switch.

I believe they use police on the ground for that purpose.

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

[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.

[markomalley]

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

EZ Pass is basically an RFID system.

They have fixed RFID detectors at the "toll gates" but they also make portable ones that can be used by the police.