Officers say the woman was driving out of a private driveway on Academy Oaks onto Highway 168 when she pulled out in front of a pickup truck traveling eastbound on the freeway.
Officers believe the woman didn't see the truck, and the other driver was going the correct speed limit.
The woman died on the way to the hospital. The truck driver was not injured in the crash.
Officers say drugs or alcohol were not a factor in the collision.
The cause of the crash is under investigation.