The accident happened about 10:55 p.m. Saturday between Quintilio Drive and Route 7.
The victim was attempting to cross the westbound lanes from north to south when she was struck by a 2009 Toyota Camry in the center lane.
The driver of the car, Terry Berry, 33, of Newark, made a U-turn and returned to the scene, police said, stopping in the left lane.
The victim landed in the left lane and was later pronounced dead at the scene. Her body was turned over to the Division of Forensic Science to attempt to determine her identity.
Police said she was not using a marked crosswalk and alcohol appears to be a factor on her part.
Berry, who was not injured, was charged with driving under the influence and driving an unregistered vehicle. But police said the primary cause of the accident was the pedestrian’s failure to use a crosswalk.
Westbound U.S. 40 was closed about 3 hours as police investigated.