notfred is wrong on the bridge. San Mateo-Hayward (route 92) is no bikes. Dumbarton (route 84 is the way across the bay on bike.
Whichever would be shorter/quicker/easier - either Redwood City to Fremont across the Dumbarton or Redwood City to Milbrae - then onto BART.
I have commuted across the Dumbarton many times and it is not a tough climb.
Check the map for your best route.
luck,
Jeff still fat