Andrea Kuiper was 26 years old when she left Virginia and went missing in California, authorities said.
The Orange County Sheriff's Department identified her as the woman who was hit after the FBI matched her fingerprints in a national missing persons database.
Ms Kuiper's family said they were "thankful" for the closure.
"We are thankful to know what happened to our daughter after all these years," said her father, Richard Kuiper, according to the sheriff's department.
An unidentified 26-year-old woman was hit while crossing the Pacific Coast Highway in Huntington Beach, California, on 1 April, 1990.
The Orange County Sheriff's Department's Coroner Division said it worked to solve the case for years.
"We never forgot her and would regularly pull out her file to see if we could think of anything new to try," Supervising Deputy Coroner Kelly Keyes said in a statement.
"The investigators at the Coroner's Office never stopped trying to figure out who she was."
Ms Kuiper, who left her home in Fairfax, Virginia, was last heard from by her family a few months before her death, the sheriff's department said.
She had suffered from manic depressive disorder, her parents said.
In 2010, the National Missing and Unidentified Persons System (NamUS) was created, providing a searchable database to help solves cases involving unidentified victims.
The sheriff's department put her details in the database shortly after it was created.
In 2017, NamUS partnered with the FBI to examine fingerprints from the database against those from unsolved cases, which led to Ms Kuiper's match.
A woman who was fatally struck by two cars while crossing a California highway in 1990 has been identified as a missing person, according to police.