How to get to San Francisco
(and leave your car in Santa Cruz—where there's no parking problem)
The trip from Santa Cruz to San Francisco is straightforward, involving only the Highway 17 Express and Caltrain, with only a single transfer at the San Jose Diridon Station. The trip will take between two and three hours, depending on the time of day, and whether you travel on a weekday or a weekend. Most trips take about two and a half hours.
The complete schedule is here. The total fare from Santa Cruz is $14 (regular), or $7 (senior, aged 65 or over), or $11.50 (senior, aged 62 to 64).
Buy your Caltrain ticket (within four zones) before boarding the Caltrain. It can be purchased either from the Caltrain ticket machine or at the counter in the Station lobby.
Once you're in San Francisco, it's easy to get anywhere in the city using the MUNI. Muni operates approximately 80 routes throughout San Francisco with stops within 2 blocks of 90% of all residences in the city. For example, it's a 45-minute ride on the N-Judah train from the Caltrain Station to the Ocean Beach at Judah, or you can walk north from the Caltrain Station one long block to the AT&T Park, or get to Candlestick Park via the T-Third (to Gilman/Paul) and the 87 shuttle. A complete list of all the MUNI buses and trains available from the Caltrain Station is here.
The basic fare to ride on the MUNI is $2, or $0.75 if you're 65 or over. (There is one exception: If you want to ride a cable car, it's $6.00, no matter how old you are.) The new Clipper Card is especially useful. The Clipper Card works on MUNI, BART, Caltrain, VTA, SamTrans and several other Bay Area carriers. (Note: Clipper Cards for seniors—for which one must apply in person—are available at many locations. The location closest to Santa Cruz is the VTA Downtown Customer Service Center in San Jose, at 1st & Santa Clara.)
Consider taking your bicycle
The Highway 17 Express has space for three bicycles in its front rack, and every Caltrain accepts bicycles, with two of its cars specially equipped to carry a total of up to 80 bicycles. Once in the City, you can, for example, ride your bike across the Golden Gate Bridge and back. For tips on taking your bicycle on the Caltrain see this page.
How to get to the San Francisco Airport (SFO)
(and leave your car in Santa Cruz—again where there's no parking problem)
The trip to SFO from Santa Cruz takes between two and two and a half hours, depending on the time of day. The total fare from Santa Cruz is $16.05 (regular), or $10.05 (senior, 65 or over), or $13.55 (senior, 62 to 64).
Start out as if you were going to San Francisco, taking the Highway 17 Express to the San Jose Diridon Station. Then get on the Caltrain (after purchasing your ticket—within three zones, not four) and take the train to Millbrae.
At the Millbrae Station, purchase a BART ticket from the machine, and board the BART train (one stop) to San Bruno, where there is a timed transfer to the train to SFO. The BART fare is (alas) $4.05, taking a total of 11 to 12 minutes to reach SFO. BART trains generally run every 15 minutes. On weekends (and evenings) BART travels directly from Millbrae to SFO, with no need for the transfer at San Bruno, cutting the time by about 5 minutes.