Dear Parking Guru,
 
Big fan here. You have made me look like I am smarter than I am on a topic that unites San Franciscans of all shapes and sizes!
 
I've never seen this topic covered before, so I thought I'd ask. When I am driving back into the City from Oakland, I can never figure out if I can use the carpool lane. Some signs say "Carpool Lane M-F", other signs only say "3 people required for carpool".  If it is a Saturday, and I have 2 people, can I use the lane? Or do I have to have 3 people? Or am I not charged with 3 people but charged with 2 people? I am sometimes tempted to pull a Larry David and pick up a "friend" on the way back from Oaktown just to speed through the carpool lane and save myself 20 minutes of cluster-f misery.
 
Thanks Guru!!!!!
JR







 
Dear JR,
 
Great questions.  I'll try to boil down the miles of rules and regulations posted on the Bay Area Toll Authority website. But keeping true to form, the answers are not black and white, and the boiled-down version is most likely going to exceed the 500 word limit requested by my very understanding and accommodating editors. The answers not only depend on what day it is and what time it is as, but they also depend on other factors such as: Where you are coming from, what sort of vehicle you are driving, and which type of carpool lane you want to use (yes, all carpool lanes on the Bay Bridge approach are not equal, and choosing the wrong one could cost you several hundred dollars...even if you are a carpool).
 
For the sake of simplicity, I'll start off with a basic situation, and then I'll get into the extra-credit Bay Bridge situations that our driving instructor didn't tell us we had to study for.
 
Let's assume that you are headed from Oakland on a Saturday and are heading to SF via 580 and make it to the area a few hundred yards away from the toll plaza that you referred to quite poignantly as the "cluster-f."  Everyone is trying to figure out where the Fastrak lanes are, but even those lanes are not moving because everybody has Fastrak now. But, on the extreme left side, traffic is flowing in the diamond carpool lane that later, rather than bottle necking, expands the flow into two lanes.

Many cars cruising by you are indeed a 3+ person carpools.  But some cars only have 2 people.  Some only have one person. WTF? Can I use it or not?  Why is most everyone else who is driving alone just sitting in stopped traffic?
 
Are those single drivers zipping along in the carpool lane:

A) Scofflaws?
 
B) Those risk takers who have less adrenaline receptors than most of us and need more risk to feel stimulated?
 
C) The type A+ people that feel entitled to cut to the head of the line in every situation?
 
D) Or the law-abiding citizens that know something that you don't know and getting to SF way before you do?
 
The answer is "D". The carpool lanes, once you are getting close to the Bay Bridge, are regular carpool lanes governed by the typical signs that state the days and times that the carpool rules are in effect, and how many people are required to consider the vehicle a carpool.
 
You are correct in noticing that some signs say "Carpool lane M-F", other signs only say, "3 People Required for Carpool".  They both are true, and your confusion is because you are probably a fast reader.  They alternate signs because everybody cannot absorb all of the information if it were on only one sign when driving at 60 mph.  So, if it is Saturday or Sunday, and you are driving alone, you are free to use the carpool lane, but have to pay the regular fee. And if it is M-F, and you are driving alone and it is not 5am-10am or 3pm-7pm you are also allowed to use the diamond lane.
 
Now for the bonus info that could save you $271.  If you are driving on 580 from Berkeley, or 880 from the Coliseum headed to SF, there are exits with separate ramps that bypass the toll plaza altogether with these 2 signs posted:

These signs are interpreted like this: These lanes are for commute buses only!  If you are a carpool, you may only use these bypass ramps from 5am-10am and 3pm-7pm M-F and you must have Fastrak.  If you use these ramps at any other time, and you are not driving a bus, even if you have 5 people in your car, even if it is Saturday, there is a good chance that a CHP motorcycle cop will be waiting for you at the top of the ramp.  You will say, "But it says carpools only M-F, so I can use this lane on Saturday right?" And he will say, "No. Only Buses can use it on Saturdays."  You will say, "How am I supposed to know that?"  And he will say, "Because it says so on the ambiguous signage."
 
But you are good to go on the carpool lanes in the cluster-f zone, and on freeways when they just post the regular alternating signs.

A good tip when the timing is right to shave off some time is to synchronize the clock in your car to Bay Bridge toll time. On a day when it is not too busy, pay cash and get a receipt. On that receipt will be the exact time according to the toll sergeant. This is important because the ruling of any contested violation is based on "the time clock or time keeping device at the toll collection point".

Synch your clock to that time.  On days when it is getting close to the end of the carpool times, you can go into that lane knowing that you will not be in violation.
 
Lastly, there are special circumstances that also qualify you as a carpool even though you have only 1 or 2 people in the car:

If you are on a motorcycle, if you are a hybrid vehicle displaying an eligible sticker issued by DMV, or you have a two-seater vehicle with 2 people in it. I hope this clears it up for you.
 
For more circuitous, but accurate explanations of the Bay Area rules of the road, click here.