Caltrain broke new ground in September by serving 50,821 average weekday riders - a new all-time high.
That number comes on the heels of 26 consecutive months of ridership growth, and it is the second month in the past calendar year that has seen ridership totals of more than 50,000.
Shuttle ridership increased by 52.1 percent in September to 10,247 riders. The shuttles provide an important last-mile connection for commuters using the train to get to work sites off the rail system.
In a statement issued Thursday, Caltrain spokespersons said, "The continuing growth in shuttle usage reflects regional job growth and a rebounding economy."
Caltrain also served huge numbers of people headed to special events in San Francisco, including baseball game service, service to Stanford football games, and service to Opera at the Park.
The Opera at AT&T Park drew a 37-percent ridership increase over ridership to the event a year ago, while baseball ridership grew by 12 percent.
The special event service was capped off with a record-breaking day for transit usage throughout the Bay Area as Giants fans headed to the World Series Championship Parade on Halloween Day. Caltrain carried more than 88,000 riders Oct. 31, marking its largest single ridership day ever.
The previous record was set during the 2010 Giants Parade when Caltrain carried roughly 80,000 riders.
However, Caltrain's ridership growth comes with some challenges for the aging rail system.
On-time performance has dropped over the past month. A series of signal malfunctions, mechanical problems and isolated events "beyond the agency’s control" caused the performance degradation, Caltrain spokespersons said.
"It’s especially difficult to recover service after a major delay during the peak, because there are limits to the additional equipment and crew that can be brought in to help offset delayed schedules," read Caltrain's statement on Thursday.
Additional minor delays due to heavy ridership throughout the system compound other performance issues, the statement said.
"Large crowds take longer to safely board the train, lengthening the dwell time for those trains," spokespersons said. "Caltrain is working closely with its contractor, TASI, to recover service more quickly following these events and reduce the impacts to riders."
“We really do have great customers. They are an engaged and loyal group and they deserve a high-quality service,” said Mark Simon, Caltrain’s executive officer for public affairs. “This has been a rough patch, but we’re throwing everything we’ve got at improving performance. We want to thank our customers for hanging in there through these growing pains.”