Geoff Wrote:
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> I'm curious of how the enforcement could possibly
> work. If a person cheats the system by switching
> to HOV couldn't they simply switch to Toll when
> approaching a police checkpoint? Additionally
> since police checkpoints can only reasonably be at
> HOT exits where traffic slows anyone exiting to
> 495, 66, or the Dulles toll road probably will
> never get checked so the potential for cheating is
> huge!
>
> ....
I don't believe that would work 100% and here's why: The toll-collection points will be at multiple locations on the road. You've probably seen some of them already, as they consist of two metal arms extending out over where the new lanes will be. See photo below taken several months ago of spot just north of US-50. I'm not entirely familiar with the technical workings of E-ZPass, but the way I understand it is that it works in a similar fashion to the ICC in Maryland and to the New Jersey Turnpike and other "ticket-system" toll roads in that your E-ZPass gets read multiple times. In the case of the new lanes on the Beltway, say you're going from I-95 to I-66. There's a toll gantry south of Braddock Road. It will read your E-ZPass and it will know you entered there. There will then be a gantry just south of Gallows, another just south of US-29, and another just south of I-66. (All these gantries are already in place, hence how I know where they'll be.) All of these will read your E-ZPass as well and so the system will know you're still in the Express Lanes. When the gantry located between I-66 and VA-7 doesn't read your E-ZPass, the system will know you exited, as well as where you exited, and the toll will post to your account. The ICC works in a similar fashion because you pass multiple toll gantries on your trip across and it's the first and last ones you pass that determine your toll. The "ticket-system" toll roads are a bit different in that the system there only reads your device twice, once when you enter the "ticket system" and again when you exit.
Switching the device when you're in the lanes presumably wouldn't work because your E-ZPass would have been read at every toll gantry and if you switched it from "HOV" to "non-HOV" presumably it could trigger a flag of some sort. They've said the system can communicate with the cops to tell them who's using "HOV" mode, so I have to assume that means it could be sophisticated enough to say, for example, "Black Honda with license 3M TA3 is suspect" so that the cops would check that car.