From San Diego, CA Amtrak Thruway to Fullerton, CA. 2 h 10 min. From San Diego Santa Fe Depot Amtrak train to Fullerton Transportation Center. 2 h 14 min $47. From San Diego drive to Fullerton. 1 h 41 min $11. From Broadway & Front St line 992 bus to San Diego airport, fly to Los Angeles airport, bus to L. A. Union Station station, then train to Fullerton. 4 h 42 min $250.