Every study ever done has shown that getting rid of carpool lanes is just about the worst thing you could do. All those people that were in the carpool lane are now in with the general traffic, and they're not carpooling. So there are even more cars.
The studies I've seen suggesting converting these lanes to toll lanes that allow for HOV free passes. The lanes serve a political purpose and do not solve an engineering issue. The facts are mass the conversion of single car drives to avid carpooled never happened.
