Q&A with Peggy Hellweg
You get different amounts of warning based on the distance you are from the earthquake. In Berkeley we would have gotten five seconds (for the Napa quake). The Bay Area Rapid Transit system got eight seconds because their operations center is farther away. The city of San Francisco got nine seconds. Google got about 20 seconds. Five seconds is more than enough time to drop, cover and hold on.
BART has an automated response, and they can stop the trains based on expected earthquake shaking. Every mile an hour less that the trains are going, that’s less of a hazard of derailing, and that means fewer injuries.