Trudy Joyce Barraza, 75, was killed Thursday after a rear-end collision on Highway 58 in Bakersfield, according to the California Highway Patrol.
Barraza was riding as a passenger in a Hyundai Sonata driven by a 28-year-old man, CHP said.
The Sonata stopped completely in the number two lane near Fairfax Road at about 11:35 a.m. because of debris in the roadway.
A Hyundai Santa Cruz driven by a 74-year-old Tehachapi woman then struck the back of the Sonata.
Investigators determined that the Santa Cruz was traveling at an unsafe speed and that its driver failed to slow or stop in time to avoid the collision.
Barraza suffered fatal injuries and was pronounced dead at the scene.