The DC area has all kinds of screwed up ideas like this. There are now segregated car pool lanes where solos can pay large tolls to drive. The segment of I-95 that runs into the south side of the metro area only has three lanes each way. There are traffic jams, even on the weekends.
Phoenix has a carpool lane that splits off the main freeway, sores into the air to cross another freeway, then rejoins the original.
The intersection of freeways plus the carpool lanes causes a dangerous exit ramp puzzle and traffic crunch. Just a mess.
But, someone got rich!