Alyssa Nicole Frantozzi, of San Ramon, died after her Honda became trapped under the right rear tires of big-rig on eastbound I-580 just east of Grove Way in unincorporated Hayward, California Highway Patrol spokesman officer Rob Tuazon said.
The 12:10 p.m. crash also involved a Toyota 4Runner. That driver was not seriously injured. The big-rig driver was unhurt.
Frantozzi was wearing her seatbelt, Tuazon said.
The CHP is still investigating the cause of the crash.