I-495 through the VA side of the DC suburbs uses High-Occupany Toll lanes - demand pricing on top of HOV lanes. If you have passengers, you can use them for free. If you're solo, you pay the toll. They use a switchable EZ Pass transponder to make it work without toll booths at each end.
Colloquially, they're referred to as "Lexus Lanes".
As far as a I can tell, they haven't done much to reduce congestion on the non-toll lanes. But, if you can afford $12/day (peak rate, round trip) for a 10 mile stretch of interstate, you get to avoid the dirty, unwashed masses who are stuck in the poor lanes. :)
Well, there is the same concept in LA, the 405 got "pool" lanes, usable for free when you got 2+ people in the car. The issue with this kind of lane is that it's the farthest left, and if your trip on the 405 is only a couple miles you gonna struggle most of your time to reach this lane and then leave it and reach the right lane before your exit when the road is jammed!
The concern when this got deployed in the Seattle area is that it would be poorer people who are most likely to use these. Example: somebody trying to get to the daycare by 6PM so they don't get charged by the minute for being late.
Why is this a concern? It sounds like a completely rational decision for someone of any income level to pay money for a faster trip to avoid an even great amount of money in fines...
Colloquially, they're referred to as "Lexus Lanes".
As far as a I can tell, they haven't done much to reduce congestion on the non-toll lanes. But, if you can afford $12/day (peak rate, round trip) for a 10 mile stretch of interstate, you get to avoid the dirty, unwashed masses who are stuck in the poor lanes. :)