Torn up about the disappearance of the old bus system, I am not. I don't miss it, I didn't love it, and it won't ever live on in my mind as "the good ol' days" of getting to the airport.
Is the new monorail type train perfect? Nah, but it's light years ahead of the old bus system.
Here's the deal: If you want to get on BART from the Oakland International Airport, you have to get to the Coliseum station. You used to take the terrible old bus, but they built an above-ground rail that shuttles back and forth. On the OAK side, you catch this by going outside, across all lanes of airport traffic, and heading up the tall skinny escalator. Just follow the signs. All but about 25 feet of this walk is weather protected, so even if it's raining you're out of it for the most part.
On the BART side, you exit the regular BART train and head to the end of the platform and take the escalators up. Again, just follow the signs.
The train itself is usually 3 cars, and there aren't many seats. I rode it the first week and it was shiny, plush, and sparkling clean. These days it's not bad, but the shine is off. Once you exit at the Coliseum station, you'll have ticket machines there where you can either load your Clipper Card or just use cash/card to buy a ticket. Look at the fee chart and see where you want to go by starting at "Oakland International Airport" as your departure and then whatever your destination is. Don't calculate the math from Coliseum, as there's an extra fare you pay for by boarding at the airport. It's like $6 tacked onto your fare, which, for the convenience of a ten-minute train ride (they say it's eight, but that's optimistic) is a good deal. Remember that if you fly into or out of SFO you pay an extra $5 or so for boarding BART there.
Buy your ticket, then use the turnstiles as normal to get to the Coliseum station proper. From there, it's just like any ol' BART trip.
Honestly, I love flying into OAK and taking BART into San Francisco. With only a few stops before going under the water, it's at least 15-20 minutes faster for me to get into downtown compared to flying into SFO and having all those Daly City stops. I didn't love it so much when the AirBART bus was all we had to get from the station to the airport, but this train did indeed make the difference for me. It's slick, it's automated, it runs frequently, and it takes me right where I want to go. Unless the were to re-route the actual BART line to OAK, I'm not sure what more you could do for convenience. It's not perfect, but it absolutely means that I will now skip the madhouse of SFO, get into the city faster, and only pay $1.30 more to do it. Good riddance, bus. read more