High Occupancy Toll lanes are a cost effective way to maximize the movement of people on highways. Although HOT lanes generally carry fewer vehicles and therefore maintain free flow conditions, they often carry 2-3 times as many people as general purpose lanes. In addition, the revenues generated by HOT lanes can be used to provide other transportation services, such as express bus service. People who carpool, vanpool or ride the bus use the HOT lane for free. Single occupant vehicles may also use the HOT lane if they are willing to pay a toll via a transponder that is attached to their inside front car windshields.
Tolls are usually pre-paid and deducted automatically when the car passes an overhead receiver.
There are no staffed toll booths. In a built-up environment adjacent to existing development, the cost could be considerably higher. Caltrans is currently developing cost estimates for the project. Additional funding will be needed to construct the project. Others are under consideration.