The 53-year-old woman from Concord ran west across the traffic lanes of southbound I-680 south of Pacheco Boulevard shortly after 11:30 p.m.
At the time, Janko Trifunovic, Jr., 35, of Brentwood was driving south with Melissa Meeks, 31, also of Brentwood and three children in a 2005 Honda when the woman ran in front of their car.
CHP officers said that Trifunovic was unable to avoid a collision with the woman, who fell in the road after being struck by the car.
Several more vehicles also struck the woman, who was pronounced dead at the scene. Officers suspect that the woman may have been under the influence of alcohol.
CHP officers are asking anyone with information regarding the incident to contact CHP at (925) 646-4980.