[AnthonyMouse]

FWIW HOV lanes actually increase congestion in practice, because the benefit from getting a small number of additional people to carpool is less than the efficiency loss from operating the lane at less than its carrying capacity during congestion.

And the correct analogy for what they want to do is that the road company also owns a car company and is restricting the lanes you can use and charging higher tolls for not buying one of their cars, because they want to monopolize the car market.