Metrolink’s Earthquake Warning System Proves Life-Saving Potential

JAIRO RODRIGUEZ
Senior Manager of Train Control On-Board Systems
Metrolink
Los Angeles, CA

Safety is every rail agency’s top priority, and in earthquake-prone Southern California, that extends to seismic preparedness. Metrolink, the region’s heavy-rail passenger train system, connects riders across nearly 545 route miles of track every day through a geographical area that averages more than 10,000 earthquakes each year. This constant threat was the stimulus behind Metrolink’s groundbreaking early earthquake warning (EEW) system, which launched on all Metrolink-owned and operated line segments in 2023.

The first-of-its-kind partnership with the U.S. Geological Survey integrated ShakeAlert technology with Metrolink’s Positive Train Control (PTC) system, enabling earthquake detection sensors to communicate real-time, location-based data directly with Metrolink trains. The EEW system also has the ability, through PTC, to slow or stop trains automatically when dangerous conditions are present.

On April 14, 2025, a 5.2 magnitude earthquake near the city of Julian in San Diego County triggered Metrolink’s early warning system, prompting the immediate halt of three trains on the San Bernardino Line and marking the first full-stop response since the technology was implemented. Based on localized shaking, several trains on the Orange County, Inland Empire-Orange County, and 91/Perris Valley lines also received informational alerts or had speeds automatically reduced.

While Metrolink’s pioneering EEW system has previously slowed trains during seismic events, this activation was the most significant to date. Throughout the event and its aftershocks, communication remained uninterrupted, providing continuous data that helped crews navigate the situation safely and efficiently.

ShakeAlert’s robust network of sensors enables tailored alerts for each train by factoring in precise locations and nearby seismic conditions. This capability is critical for safely managing operations across Metrolink’s expansive six-county network. By automating responses, Metrolink significantly shortens the time between detection and action, which helps reduce derailment risk, minimize damage, and protect lives.

In an environment where earthquakes are inevitable, Metrolink is transforming risk into readiness and reaffirming its position as a national leader in rail safety and resilience.