The collision happened on northbound lanes of Highway 99 near Clinton Avenue just after 1:30 am on Saturday.
The woman, 31-year-old Jeanette Ward of Fresno, died at the scene of the crash.
Investigators are still trying to figure out why she ran out onto the highway.
The driver involved in the crash remained on scene and was found to be driving under the influence.
That driver was booked on DUI charges but isn't being charged with Ward's death.
Investigators say that's because the driver wasn't the person at fault in the deadly crash.