By bus
AC Transit
The U line runs from Stanford University to the Fremont BART station, and the Dumbarton Express DB line runs from Palo Alto through Ardenwood to the Union City BART station, but only during weekday commute hours.
Valley Transit Authority (VTA)
Line 180/181 bus runs from downtown San Jose to Fremont BART station, including service on weekends and holidays.
By train
Amtrak Capitol Corridor
The Capitol Corridor is an Amtrak route from downtown Sacramento to downtown San Jose passing through Fremont's Centerville district. From this line, you can transfer to BART at the Oakland Colliseum, or connect to long distance trains at the Emeryville depot. There are also bus links to the western outskirts of Oakland and Berkeley, and a short bus ride to downtown San Jose.
BART
Bay Area Regional Transit service has its southernmost stop in Fremont; the line ends here for now. From Fremont there are trains north through Oakland, with Richmond or Daly City as their final destinations. By changing trains it is also possible to go inland all the way to Dublin/Pleasanton or to continue beyond Daly City to Millbrae, passing San Francisco International Airport SFO on the way. Construction is underway to extend BART south to Warm Springs/South Fremont (http://www.bart.gov/about...) 2014 and the Alameda county line. From there, VTA/BART Silicon Valley (http://www.vta.org/bart/) will extend the BART line further south into Santa Clara county, first to Milpitas and Berryessa in northeastern San Jose opening 2016, and then in the distant future, with a little bit of luck and a lot of funding, through a downtown San Jose subway to Santa Clara.
Altamont Commuter Express (ACE)
The ACE train connects towns east of Fremont with the Silicon Valley. This train runs only from the east four times a day during the morning commute and to the east four times a day during the afternoon/evening commute.
By car
From Oakland and Berkeley, take I-880 south
From San Jose, take I-880 or I-680 north
From San Francisco and Palo Alto, take US-101 to either US-92 or SR-84 the Dumbarton Bridge; preferred
From more eastern parts of the region or the central valley, get to I-680 and head south