Yes. Even if you have the required number of occupants in your clean air vehicle to qualify as a carpool vehicle (either two or three, depending on the carpool policies of the bridge you are crossing), you must still pay a toll. However, like all other high-occupancy vehicles, you qualify for a discounted carpool toll rate of $3.50 on all state-owned toll bridges and $6.75 on the Golden Gate Bridge.
Topic: Special Vehicles