Weekend riders on the southern end of the Caltrain line are in for a bumpy summer. The railroad is temporarily suspending regular Saturday and Sunday service between San Jose Diridon and Tamien stations so crews can finish work on the aging Guadalupe River Bridge. The closures start this weekend and continue on select weekends through mid-September. Weekday trains are still expected to run as scheduled, but anyone riding on weekends will need a backup plan.
The warning went up on Caltrain's X account and on the agency's service-status page, which lays out the full closure schedule and rider guidance. According to the status page, there will be five affected weekends between July and September, and there will be no replacement bus service covering the gap during those shutdowns. Weekday trains between Tamien and Diridon will operate as normal, per Caltrain.
Caltrain Temporarily Suspending Train Service Between Diridon and Tamien Stations to Complete Repairs to Guadalupe River Bridge, read more: https://t.co/1TbyHKOcob .
— Caltrain (@Caltrain) July 8, 2026
Which weekends are affected
If you count on rolling between Diridon and Tamien on Saturdays or Sundays, these are the dates to circle in red: this weekend, July 11-12; July 25-26; Aug. 8-9; Aug. 22-23; and Sept. 19-20. Riders who usually board at Tamien on weekends should expect a hard stop at Diridon and adjust their trips around the gap.
Why crews are closing the line
The shutdowns are tied to the Guadalupe River Bridge Replacement Project, a multi-season effort to replace or extend two bridge spans and shore up the riverbanks to boost seismic safety and cut erosion risk. Local and industry coverage note that the northbound span is being replaced while the southbound span is being lengthened, work that has triggered periodic service changes since 2025, as reported by SFGATE.
How riders should plan
Caltrain says weekday trains will continue to run normally and urges riders to double-check schedules before heading out, especially on the affected weekends, and to keep an eye on @CaltrainAlerts for real-time updates. For deeper details on the bridge project and its timeline.
Earlier this year, Caltrain restored service to Tamien in January, so this latest move is a targeted, short-term weekend disruption rather than a permanent rollback at the station. Expect more advisories as crews work through the remaining bridge construction and plan accordingly.
