SamTrans Buses 7B and 7F 5:30AM - 1AM at 30' intevals- no luggage on 7F. Stops at the upper level at the Sam Trans sign. 7B: $1.10, 7F (Express): $3. To Transbay Terminal, 1st at Mission, downtown. 30 (Express) to 50 minuts (7B). Express has about 3 stops in downtown SFO.
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Free CalTrain Shuttle from the SamTrans boarding area upper level to Millbrae CalTrain Station. A shuttle meets every train. CalTrain was 2$ (2 years ago) to downtown SFO, $4.50 to San Jose. Info 800-532-8405.