I searched the forum and found nothing posts on this issue after 2007. I recently bought a used Prius with the CA HOV sticker. In the material that came with Fastrak it stated that a vehicle with the HOV sticker AND with the required passengers for regular carpool access can cross bay area bridges toll free during designated commute hours. But I later read on the Fastrak website that since July 1, 2010, this is not true anymore. Even if a hybrid has the required number of carpool passengers they still have to pay $2.50. Can someone clarify as to which is correct?
During carpool hours, must have a Fastrak which gets charged $2.50 in the carpool lane. This is for all bridges, except the Bay or Golden Gate has a slightly different arrangement. Free carpool is gone.
Actually hybrids with yellow stickers got a break here. Formerely, during car pool hours, you could still use the car pool lanes, but you were charged normal toll. However, now, during car pool hours you pay $2.50 whether or not you are carrying passengers. See here. Note that yellow-stickered hybrids pay the non-carpool rate on the Golden Gate Bridge (it's run by a different agency).
Also to note; if you buy a used Prius that has official HOV stickers you are supposed to "transfer" them into your name via the DMV in Sacramento. There is no fee for this but it takes a few weeks by mail. Call the DMV for info, you cannot do it at your local DMV office, form must be mailed to Sacramento. You then need to get a special FastTrak tag for your Hybrid "sticker" car. The last HOV stickers for Hybrids were issued in early 2007. If you have an 08 or newer car with yellow stickers something is not right. I've seen cars for sale on CL with stickers, but when you call the DMV with VIN or license plate they say "that car has no record of stickers"...ie. someone put stolen or counterfeit stickers on the car. If you buy a Prius with stickers, make sure the seller shows you proof of the stickers belonging to that car. Once you have paperwork in order and a special FastTrak tag you can take the bus lane during rush hours over the bridge with any number of people in the car. You will be charged $2.50 westbound. Eastbound is still free (for everybody).