Troopers responding to a shots fired call at Exit 6 in Greenwich Township, which runs through a truck weigh station, found the woman in her vehicle shortly before 6 a.m., the NJSP said.
She was "conscious and alert," having sustained gunshot wounds to her head, hand and chest, State Police said.
The 39-year-old victim was conscious but unable to speak when taken to a hospital by ambulance, responders said.
She was listed there in stable condition, State Police said.
"Detectives believe that the shooting may have been the result of an incident that occurred between the victim and the unknown suspect motorist on Interstate 78 east between Exit 75 (Morgan Hill Road) in Easton, PA and Exit 6 in New Jersey," they said in an afternoon statement.
He apparently is white, was wearing dark clothing and fled in a dark-colored sedan, the NJSP said.
Anyone with information that can help find the assailant is asked to contact the New Jersey State Police Perryville Station at (908) 730-7042.
Anonymous tips are welcome.
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