The man was driving west on Mercer Island in his pickup truck when he noticed a woman in a nearby sedan slumped over her steering wheel. She had just struck a jersey barrier on the north side of the freeway and was veering back across the lanes of traffic, troopers said.
The man managed to maneuver his truck in front of the woman's sedan and was able to bring it to a stop just east of Island Crest Way, troopers said. Medics responded and took the woman to the hospital. Troopers say the woman had likely suffered a seizure.
Both cars sustained minor damage and no one else was hurt.