Yes, you have to sift through the BS a bit. It didn't used to be so bad here.. but it seems so many people that don't know.. like to chime in and act as if they do. As NOID said.. if you don't know.. then STFU. Well, he said it nicer than that, but that is what he meant.
The correct answer is in post #7. Refer to the link there for the offical answer: HOV lanes on Hwy 80 in Alameda County approaching the SF Bay Bridge are: "Three or more persons per vehicle, motorcycles, two-seat vehicles with two persons."
Also, from the FAQ at the Bay Area Toll Authority website:
http://bata.mtc.ca.gov/faq.htm
"18. What are the HOV/carpool-lane restrictions at the bridges?
HOV/carpool hours and occupancy requirements vary by bridge. Signs at each toll plaza and on the bridge approaches designate the carpool-lanes and any bridge-specific restrictions on use, including hours and occupancy requirements. For more bridge-specific information
[CLICK HERE] "
That link takes you to their schedule which states: "Note: Any motorcycle, bus, inherently-low-emission vehicle (ILEV) with DMV-issued decals, or
2-axle vehicle, without trailer(s), designed by the manufacturer to be occupied by no more than two persons, carrying two persons, may also cross toll-free in designated lane(s) consistent with the above referenced hours of operation."
FWIW, BARFers that back up their answers with actual CVC sections (that apply) and links to official/credible websites or previous threads where the answer has been given get "extra points" and should be the ones you heed. All others are suspect.