It operates three different service typologies:

• Local: stopping service, calling at all stations. Trains sometimes call at Broadway (weekends and holidays only), Stanford (game days only), and College Park (weekday peaks only). In the current schedule (effective June 15, 2020), two trains, one in the morning and one in the afternoon, operate as a Local to and from Gilroy.
  • For access to Tamien Station on weekends and holidays, a shuttle service is provided from San Jose Diridon Station, timed to most train arrivals and departures.
• Limited: skip-stop service, calling at select stations along the line. This service type operates weekdays only during the morning and afternoon peak in both directions. In the current schedule (effective June 15, 2020), all Limited trains call at San Francisco, Millbrae, Belmont, Palo Alto, and San Jose Stations.
  • Limited “A” trains also call at South San Francisco, Burlingame, San Carlos, California Avenue, Mountain View, Lawrence, and Tamien.
  • Limited “B” trains also call at 22^nd Street, San Bruno, San Mateo, Redwood City, Menlo Park, San Antonio, Sunnyvale, and Santa Clara.
• Baby Bullet: the fastest service variant, calling at fewer stops than the Limited. These typically call at San Francisco, Millbrae, Palo Alto, and San Jose, with some trains calling at 22^nd Street, San Mateo, Hillsdale, Redwood City, Menlo Park, California Avenue, Mountain View, and Sunnyvale Stations. The fastest Baby Bullet services complete the trek in around an hour.
  • As of the May 16, 2020 schedule, Baby Bullet trains operate twice on weekends and holidays, calling at San Francisco, Millbrae, San Mateo, Belmont, Redwood City, Palo Alto, Mountain View, Sunnyvale, and San Jose Diridon.
  • For access to Tamien Station on weekends and holidays, a shuttle service is provided from San Jose Diridon Station, timed to most train arrivals and departures.

Its service span and frequency are as follows:

Caltrain also connects with other rail services along the line, including:

• Muni Metro at San Francisco 4^th & King
• BART at Millbrae
• VTA Light Rail at Mountain View and San Jose Diridon

Note, however, that transfers between Caltrain and the above agencies may not hold for passengers coming from late arriving trains. And passenger cars can be swapped between the Bombardier and Nippon Sharyo for both train engines depending on both demand and carriage availability.

Locomotives

Two locomotive types currently operate with Caltrain, all of which allow push-pull operations.

Units 900 to 919 are the EMD F40PH-2 locomotive units, all of which are named to a particular community or county along Caltrain. Units 902, 903, 907, 910, and 914 have the gear drive HEP (head-end power). Units 900, 901, 904, 905, 906, 908, 909, 911, 912, 913, 915, 916, 917, 918, and 919 have the Caterpillar 6-cylinder HEP generator (EMD F40PH-2-CAT). 

Units 920, 921, and 922 are the Boise F40PH-2C locomotive units, all of which are also named to a particular community in southern Santa Clara County. These have the Cummins HEP generator. 

Units 923 to 928 are the MPI MP36PH-3C locomotive units.

Passenger Cars

Six passenger train types operate with Caltrain: Bombardier Bilevel (cab car, regular passenger cars, and ex-Metrolink 2nd generation passenger cars), and Nippon Sharyo Gallery Bilevel (cab cars, luggage cars, and regular passenger cars).

Bombardier Bilevel Passenger Cars. Nine cab cars, numbered 112 to 120, lead trains in the northbound direction. An additional 16 units (numbered 219 to 226, and 229 to 236) are trailer passenger cars with varying number of seats per car.

Ex-Metrolink Bombardier Bilevel Passenger Cars (1997). Sixteen units (164, 165, 167, 169-173, 175-182) were purchased by Caltrain in 2016 to provide additional passenger capacity on its trains. These are combined with the Caltrain Bombardier units (both cab and trailer).