The incident happened at about 2 a.m. on the Pacific Avenue off-ramp. Investigators say a man driving the Toyota SUV lost control of the vehicle and crashed.
The woman, who was a passenger, died at the scene. The driver, only identified as a 45-year-old man, was taken to Los Angeles County-USC Medical Center, according to California Highway Patrol.
The off-ramp was closed for several hours as emergency crews cleared the scene.
There was no word on whether wet roads contributed to the crash.
The Associated Press contributed to this report.