The woman lost control of her car. It then plowed through a guardrail and then plunged 70 feet onto State Street below.
Police say the crash happened as the woman was traveling north on I-95, just south of the Cottman Avenue exit in Tacony, around 1:30 a.m. Sunday.
The woman was taken to the hospital with serious injuries.
Police are still investigating how she lost control of her vehicle.