The Caltrain commuter rail system links San Francisco with San Jose / Gilroy and the cities in between. Originally built in 1863 by Southern Pacific, today the system offers local and express service between the numerous residential and commercial areas in the SF Peninsula and Silicon Valley. With 60,000 daily riders as of 2016, Caltrain’s single line ranks among the busiest rail corridors in the US, and a ridership of 110,000 is anticipated by 2050.

In April 2017, Caltrain made the following changes to its schedule, the most significant in the past decade:

Adjust trains 101 & 103 for same a rrival of current schedule at the San Francisco Caltrain Station

No added stops to train 305 schedule

Additional California Avenue stops for trains 211 & 221

Additional Redwood City stops for trains 314 & 324

Additional Hillsdale stop for train 230

Adjust train 102 at the Mountain View station to improve VTA connection

Adjust train 233’s schedule to improve ACE Rail and Capital Corridor connections at the Santa Clara station

Separation of southbound AM peak Baby Bullet trains 312 & 314 and 322 & 324, which currently operate back-to-back, for improved efficiency and time spacing for passengers

Revised Train Numbers and Departure Times: Existing train 210 becomes proposed train 212 Existing train 312 becomes proposed train 310 Existing train 220 becomes proposed train 222 Existing train 322 becomes proposed train 320 Existing train 230 becomes proposed train 232 Existing train 332 becomes proposed train 330

Additional Sunnyvale stop for train 287

Additional Redwood City stops for trains 371 & 381

Additional California Avenue stops for trains 366 & 376

Additional Santa Clara stops for trains 262 & 272 for improved ACE and Amtrak connections

Adjust train 198 for later departure out of San Francisco station Additional changes include: Departure time adjustments during off-peak periods to enable all train meets to occur at control points that will allow flexibility to the operation to accommodate PCEP work windows

Minor revisions for clock face departures

Added dwell time to Top High-use Stations during the Peak Hours

Hourly reverse peak service to Tamien: Eliminate Tamien Station service due to very low ridership: AM Reverse Peak Trains: 208, 218, 228 PM Reverse Peak Trains: 263, 273, 283, 287 Add Tamien Station service for various trains: AM Peak Trains: 310, 320, 330 PM Peak Trains: 289



Caltrain made minor adjustments to the existing timetable in October 2017, and the next set of changes are scheduled to occur in April 2018.

This post represents the first in a series of articles that will analyze Caltrain’s own ridership numbers in order to make appropriate modifications to the schedule to distribute crowding better and to improve service reliability.

The Commute-Hour Capacity Crunch

Partially fueled by the booming tech industry, Caltrain has experienced high ridership growth since 2010. As the table below demonstrates, many of Caltrain’s peak hour trains, in particular the morning express trains to SF, have become extremely overcrowded. While Caltrain has lengthened several of its train sets to 6 cars for 20% additional capacity, many trains remain standing-room-only, as Caltrain’s recent ridership report indicates.

Caltrain’s busiest trains in the northbound direction. Source: Caltrain 2016 Ridership Report.

During the morning peak (defined as the trains that depart SJ Diridon between 5:30 AM and 10 AM PT), Caltrain runs the following trains:

Trains 3×6

Full numbers can be found at this link. To summarize, nearly all trains departing SJ Diridon between 6:30 and 9:00 A.M. exceed their seated capacity at some point during their trips to SF. The exceptions are Trains 221 and 231, which have lower ridership because they run local in San Mateo County.

Aside from time adjustments, Caltrain has proposed only one major change in the AM northbound direction for April 2017: Train 305 will be converted into a limited-stop train that makes the same stops as Trains 215 and 225. Given that this early-morning train runs only at half capacity, this change is justified, as taking on additional passengers will help alleviate increasing heavy early traffic in the South Bay and Peninsula.

While resources are limited, Caltrain can still leverage existing trains to address overcrowding during the AM peak hours. Here are some suggested changes, roughly arranged in order of priority from highest to lowest.

Additional Proposed Changes

Add an additional stop at Palo Alto to Trains 211, 221, and 231.

Currently, 1261 riders on Trains 217, 319, 227, 329, and 233 get off at Palo Alto. These trains are carrying on average 800 riders when they arrive at Palo Alto, while Trains 211, 221, and 231 average only 400 riders, half that number. These timed transfer trains currently skip the second busiest station in the system, resulting in a 30 minute gap in service at Palo Alto. Stopping these three trains at Palo Alto would divert SJ, Sunnyvale, and Mountain View passengers from the other overcrowded trains, resulting in lower dwell times and more reliable service. This change would reflect a similar 2012 schedule change, in which reverse-peak Baby Bullets that had previously skipped Palo Alto began stopping at that station.

Originate Trains 215 and 225 at Tamien.

Currently, baby bullet trains are departing San Jose near capacity, leading to overcrowding at Sunnyvale or Mountain View. On the other hand, the limited trains do not reach capacity until San Mateo County. To take advantage of spare capacity, trains 215 and 225 should originate at Tamien, which is currently served only by trains from Gilroy and the Baby Bullet ‘B’ trains during rush hour. These trains will divert riders away from the overcrowded baby bullets, and add additional service options for riders coming from South San Jose.

Improve spacing between Trains 215 and 319, as well as 225 and 329.

Limited trains 215 and 225 run between baby bullet trains 313/319 and 323/329, respectively. As such, they are only five minutes apart from each other in San Mateo County, which causes frequent train slowdowns. To improve spacing between these trains, the following adjustments should be made:

Trains 215 and 225: Stop at Hillsdale removed; use Trains 319 and 329 instead.

Trains 319 and 329: Stop at Hillsdale added, and stop at San Mateo removed.

This change is likely to be the most controversial, since San Mateo will be losing service (albeit trains are stopping at San Mateo only 5 minutes apart from each other currently). As compensation for San Mateo riders, Caltrain could consider adding a San Mateo stop at Trains 217 and 227, although those trains experience heavy crowding.