| CalMod | |
|---|---|
 | |
 A Caltrain KISS electric trainset in revenue service in August 2024 | |
| Location | San Francisco Peninsula, California, U.S. |
| Owner | Caltrain |
| Established | July 21, 2017 (groundbreaking) |
| Status | Partially operational |
| Website | calmod |
The Caltrain Modernization Program (CalMod), sometimes referred to as the Caltrain Electrification Project, was a $2.44 billion project which added a positive train control (PTC) system and electrified the main line of the U.S. commuter railroad Caltrain, which serves cities in the San Francisco Peninsula and Silicon Valley. The electrification included installation of a 25 kV catenary system over the double-tracked line from San Francisco to San Jose, and acquisition of new rolling stock, consisting of Stadler KISS double-decker electric multiple units (EMU). Caltrain is transitioning from its legacy push-pull trains hauled by diesel-electric locomotives, most of which have been in service since 1985.
Construction for CalMod began with a groundbreaking ceremony at Millbrae station on July 21, 2017 and completed in April 2024; after testing, inaugural revenue service with EMUs running under the overhead catenary began just over seven years later, on August 11, 2024. According to Caltrain, benefits accrued by electrifying the tracks and switching to EMUs include improved service times via faster acceleration and shorter headways, and reduced air pollution and noise. In addition, it enabled planning and implementation to proceed for The Portal, a planned railway tunnel to extend service approximately 1 mi (1.6 km) from its existing northern terminus into the rail station shared with California High-Speed Rail under downtown San Francisco's Salesforce Transit Center, as diesel trains cannot serve underground stations.