Charles A. Allison, Jr., 48, was under the influence of methamphetamine and amphetamine when he rear-ended the BMW on the northbound 101 at the Nojoqui Creek Bridge near Buellton on January 12, according to a toxicology report released by the California Highway Patrol.
Kelli L. Groves, 36, and her two daughters had to be rescued from the BMW, which was dangling over the freeway overpass.
Her 10-week-old girl was "conscious and alert" at the scene and sustained minor injuries. Groves and her 10-year-old daughter suffered major injuries.
The santamariatimes.com described the collision as a violent one that blew out chunks of concrete guardrail on both sides of the bridge. The crash shut down both directions of the 101 freeway.
The truck spilled approximately 50 gallons of diesel fuel in the creek bottom, the fire department said.
The rescue effort was aided by a group of Navy Seabees who were stuck in southbound traffic near the crash. They used a forklift they were transporting to stop the BMW from sliding off the bridge.