A semi-truck struck the 54-year-old woman as she crossed the southbound lanes of the highway near the Broadway exit, moving west from the center divider. Emergency personnel pronounced her dead on the roadway, according to the CHP.
The victim's name has not been released because her family has not been notified of her death, according to the San Mateo County coroner's office.
The crash was reported around 12:50 a.m., CHP Officer Robert Haven said. Drivers on southbound Highway 101 were directed off the highway at Broadway while emergency crews and the coroner responded, Haven said.
A Sig-alert was issued around 1:10 a.m. and canceled around 2:40 a.m., Haven said.